From willamette-fcst at listsmart.osl.state.or.us Thu Jul 1 17:11:22 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 01 Jul 2010 19:11:22 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 01 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT THU JUL 01 2010 ...Corrected Burning Instructions... WEATHER DISCUSSION: A weak cold front will bring increasing clouds today with a chance of showers by late in the afternoon. Ventilation conditions will be good, ahead of the cold, early this afternoon. Mixing heights will rapidly lower late in the afternoon and evening, due to increasing onshore flow. The high temperature, of near 70 degrees, will likely be met in the mid-afternoon with a cooling sea breeze in the late afternoon and evening. Prep burning is not allowed. Propane flaming is not allowed. TODAY: 11am 2pm 5pm 8pm Temperature: 63 70 69 63 Relative Humidity: 54% 39% 42% 60% Surface Wind Direction: 200 200 230 250 Surface Wind Speed: 6 7 8 7 Transport Wind Direction: 230 230 270 260 Transport Wind Speed: 6 10 12 15 Estimated Mixing Height: 3500 6000 3000 1500 Ventilation Index: 21 60 36 22 Sunset: 8:57 pm EXTENDED OUTLOOK: An upper-level trough will maintain cool and showery conditions on Friday. The flow aloft will turn northwesterly over the holiday weekend with dry weather and progressively warmer temperatures. The long-range computer models are indicating that an upper-level ridge will build over the region during the middle of next week, which will likely bring the Willamette Valley a couple of days of 90-degree temperatures for the first time this year. Friday: Mostly cloudy and cooler with a chance of showers. high near 67. Wind: W 5-15 mph with possile gusts to near 20 mph in the afternoon. Friday Night: Mostly cloudy with a chance of showers. Low near 50. West to northwest wind decreasing to 5-10 mph late. Saturday: Morning clouds...becoming partly sunny. High near 73. North NW 5-15 mph in the north valley and northerly 10-20 mph in the south valley. Saturday Night: Mostly cloudy. Low near 50. Independence Day: Partly sunny. High near 77. North to northwest winds. Monday: Mostly sunny. High near 80. Brisk north winds in the south valley. Tuesday: Sunny and warm. High near 88. North winds. Wednesday: Sunny. High near 92. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. From willamette-fcst at listsmart.osl.state.or.us Thu Jul 1 17:25:35 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 01 Jul 2010 19:25:35 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 01 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT THU JUL 01 2010 ...Corrected Burning Instructions... WEATHER DISCUSSION: A weak cold front will bring increasing clouds today with a chance of showers by late in the afternoon. Ventilation conditions will be good, ahead of the cold, early this afternoon. Mixing heights will rapidly lower late in the afternoon and evening, due to increasing onshore flow. The high temperature, of near 70 degrees, will likely be met in the mid-afternoon with a cooling sea breeze in the late afternoon and evening. Prep burning is not allowed. Propane flaming is not allowed. TODAY: 11am 2pm 5pm 8pm Temperature: 63 70 69 63 Relative Humidity: 54% 39% 42% 60% Surface Wind Direction: 200 200 230 250 Surface Wind Speed: 6 7 8 7 Transport Wind Direction: 230 230 270 260 Transport Wind Speed: 6 10 12 15 Estimated Mixing Height: 3500 6000 3000 1500 Ventilation Index: 21 60 36 22 Sunset: 8:57 pm EXTENDED OUTLOOK: An upper-level trough will maintain cool and showery conditions on Friday. The flow aloft will turn northwesterly over the holiday weekend with dry weather and progressively warmer temperatures. The long-range computer models are indicating that an upper-level ridge will build over the region during the middle of next week, which will likely bring the Willamette Valley a couple of days of 90-degree temperatures for the first time this year. Friday: Mostly cloudy and cooler with a chance of showers. high near 67. Wind: W 5-15 mph with possile gusts to near 20 mph in the afternoon. Friday Night: Mostly cloudy with a chance of showers. Low near 50. West to northwest wind decreasing to 5-10 mph late. Saturday: Morning clouds...becoming partly sunny. High near 73. North NW 5-15 mph in the north valley and northerly 10-20 mph in the south valley. Saturday Night: Mostly cloudy. Low near 50. Independence Day: Partly sunny. High near 77. North to northwest winds. Monday: Mostly sunny. High near 80. Brisk north winds in the south valley. Tuesday: Sunny and warm. High near 88. North winds. Wednesday: Sunny. High near 92. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. From willamette-fcst at listsmart.osl.state.or.us Fri Jul 2 09:31:15 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 2 Jul 2010 09:31:15 -0700 Subject: [willamette-fcst] Silverton Hills Forecast - Fri Jul 2, 2010 Message-ID: <8CD18C5BD70D6F4BB2B636295905299C8A13B9A7@WPODFEXCL01.ODF.STATE.OR.US> SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 A.M. PDT FRI JUL 02 2010 TODAY'S BURNING ADVISORY: Prep burning is not allowed. Propane flaming burning is not allowed. TODAY'S WEATHER DISCUSSION: An upper level trough will bring cool and showery weather to the northern Willamette Valley today. Fields are not ready for burning. TODAY'S FORECAST: Mostly cloudy and very cool with a few showers likely. Surface winds will be S at 5-12 mph this morning; becoming W 5-15 mph this afternoon. Transport winds will be SW at 8 mph this morning; becoming W at 10 mph this afternoon. Maximum mixing height today will be 4000 feet. The ventilation Index will rise to 40 this afternoon. Salem's high temperature today will be near 65 degrees. The relative humidity will drop to 50% around 2 p.m. Salem's sunset tonight is at 8:57 pm EXTENDED DISCUSSION: A drier northwesterly flow aloft is forecast for Saturday and Sunday. An upper-level ridge will build over the region late Monday through Wednesday. A surface thermal trough will build northward along the coast with the transport winds turning offshore Tuesday and Wednesday. Sinking air aloft and plenty of July sunshine will warm northern Willamette Valley temperatures to well above normal. The ridge may begin to back off the coast as next Thursday with increasing northwesterly flow aloft. That is still a dry pattern, but the low-level flow would turn back onshore...likely cooling temperatures back closer to normal by Friday. EXTENDED FORECAST: Sat July 3rd: Chance of a morning shower...becoming partly sunny. 49/71 Sun July 4th: Morning clouds. Partly sunny in the afternoon. 49/73 Mon July 5th: Morning clouds...becoming mostly sunny in the Afternoon. 50/75 Tue July 6th: Sunny and much warmer. Northeast winds. 50/87 Wed July 7th: Sunny and very warm. Northeast winds. 57/92 Thu July 8th: Sunny. Increasing onshore flow late. 60/90 Fri July 9th: Patchy morning clouds. Mostly sunny. 55/85 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Jul 6 08:33:29 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 06 Jul 2010 10:33:29 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 06 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT TUE JUL 06 2010 *** Potential Fire Marshall Conditions due to winds and humidity *** BURN ADVISORY: Agricultural burning is allowed. Suggested burn times are 11:00am to 7:00pm. Prep burning is not allowed. Propane flaming burning is not allowed. WEATHER DISCUSSION: Upper air charts show a strong ridge aloft extending from about 600 miles west of northern California northward into the Yukon. This gives a dry northerly or northwesterly flow aloft to the region. The ODF morning surface analysis shows a strong thermal trough extending from the central valley of California northward into southwestern Oregon. There is a strong northerly or northeasterly surface pressure gradient. Pressure gradients as of 8am included: Newport to Salem, 0.5 mb offshore; Salem to Redmond, 2.1 mb offshore; Newport to Redmond, 2.6 mb offshore; and Portland to Medford, 5.6 mb northerly. Smoke trajectories from both the NAM and RUC models show smoke from the Silverton Hills heading towards central Lane County. The morning Salem sounding shows an inversion from about 1500 feet to 2800 feet. This will break with a surface temperature of about 76 degrees which should be reached by 1pm. The limitation on burning today will be winds and humidity. Fire Marshal burn-ban conditions will likely be met by about 2pm this afternoon. Salem's high temperature today will be near 87 . Relative humidity reaches 50% by 10am. Minimum relative humidity will be near 24% Sunset: 8:55 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 69 79 86 82 Relative Humidity: 51% 34% 24% 29% Surface Wind Direction: 010 020 020 030 Surface Wind Speed: 13 16 17 12 Transport Wind Direction: 020 020 030 020 Transport Wind Speed: 12 20 23 10 Estimated Mixing Height: 2500 5500 7000 1000 Ventilation Index: 30 110 161 10 EXTENDED DISCUSSION: Computer models indicate the pattern tomorrow will be similar to today with a dry, offshore flow. The thermal trough shifts inland late Thursday with onshore flow developing but the generally dry, sunny and warm pattern continues through the weekend. EXTENDED FORECAST: Wednesday: Sunny, with a high near 91. East northeast wind around 9 mph. Wednesday Night: Mostly clear, with a low around 62. East wind between 3 and 8 mph. Thursday: Sunny, with a high near 94. Calm wind becoming northwest between 6 and 9 mph. Thursday Night: Partly cloudy, with a low around 60. Friday: Mostly sunny, with a high near 93. Friday Night: Mostly clear, with a low around 57. Saturday: Sunny, with a high near 91. Saturday Night: Mostly clear, with a low around 58. Sunday: Sunny, with a high near 89. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. From willamette-fcst at listsmart.osl.state.or.us Tue Jul 6 11:59:08 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 06 Jul 2010 13:59:08 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 06 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST NOON UPDATE OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 AM PDT TUE JUL 06 2010 *** Potential Fire Marshall Conditions due to winds and humidity *** BURN ADVISORY: Agricultural burning is allowed. Suggested burn times up until 7:00pm. Prep burning is not allowed. Propane flaming burning is not allowed. WEATHER DISCUSSION: Upper air charts show a strong ridge aloft extending from about 600 miles west of northern California northward into the Yukon. This gives a dry northerly or northwesterly flow aloft to the region. The ODF morning surface analysis shows a strong thermal trough extending from the central valley of California northward into southwestern Oregon. There is a strong northerly or northeasterly surface pressure gradient. Pressure gradients as of 11am included: Newport to Salem, 0.1 mb onshore; Salem to Redmond, 2.2 mb offshore; Newport to Redmond, 2.1 mb offshore; Eugene to Medford, 4.1 mb northerly; Portland to Eugene, 1.8 mb northerly; and Portland to Medford, 5.9 mb northerly. Smoke trajectories from both the NAM and RUC models continue to show smoke from the Silverton Hills heading towards central Lane County. The morning Salem sounding showed an inversion from about 1500 feet to 2800 feet. This will break with a surface temperature of about 76 degrees which should be reached by 1pm. The limitation on burning today will be winds and humidity. Fire Marshal burn-ban conditions will likely be met by about 2pm this afternoon. Salem's high temperature today will be near 87 . Relative humidity reaches 50% by 10am. Minimum relative humidity will be near 24% Sunset: 8:55 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 69 79 86 82 Relative Humidity: 51% 34% 24% 29% Surface Wind Direction: 010 020 020 030 Surface Wind Speed: 13 16 17 12 Transport Wind Direction: 020 020 030 020 Transport Wind Speed: 12 20 23 10 Estimated Mixing Height: 2500 5500 7000 1000 Ventilation Index: 30 110 161 10 EXTENDED DISCUSSION: Computer models indicate the pattern tomorrow will be similar to today with a dry, offshore flow. The thermal trough shifts inland late Thursday with onshore flow developing but the generally dry, sunny and warm pattern continues through the weekend. EXTENDED FORECAST: Wednesday: Sunny, with a high near 91. East northeast wind around 9 mph. Wednesday Night: Mostly clear, with a low around 62. East wind between 3 and 8 mph. Thursday: Sunny, with a high near 94. Calm wind becoming northwest between 6 and 9 mph. Thursday Night: Partly cloudy, with a low around 60. Friday: Mostly sunny, with a high near 93. Friday Night: Mostly clear, with a low around 57. Saturday: Sunny, with a high near 91. Saturday Night: Mostly clear, with a low around 58. Sunday: Sunny, with a high near 89. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. From willamette-fcst at listsmart.osl.state.or.us Wed Jul 7 08:56:35 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 07 Jul 2010 10:56:35 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Wed, Jul 07 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT WED JUL 07 2010 BURN ADVISORY: Agricultural burning is allowed. Suggested burn times are from 11:00am to 7:00pm. Prep burning is not allowed. Propane flaming burning is not allowed. WEATHER DISCUSSION: A strong ridge of high pressure will bring near record warm temperatures to the Willamette Valley today. Fields are not ready for burning. Salem's high temperature today will be near 98. Relative humidity drops to 50% by 8am. Minimum relative humidity 17%. Sunset: 8:55 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 81 93 98 92 Relative Humidity: 33% 22% 17% 21% Surface Wind Direction: 010 360 360 340 Surface Wind Speed: 7 9 10 9 Transport Wind Direction: 10 30 20 30 Transport Wind Speed: 10 13 17 17 Estimated Mixing Height: 1500 3500 5000 3000 Ventilation Index: 15 46 85 51 EXTENDED DISCUSSION: The strong ridge of high pressure will continue to bring near record heat to the valley Thursday and Friday with weak onshore flow bring some minor cooling over the weekend. EXTENDED FORECAST: Thursday: Sunny with near record warmth. Light north winds. 62/100 Friday: Sunny and continued hot. Wind: NW 5-10 mph. 63/96 Saturday: Sunny and slightly cooler. Wind: NW 5-15 mph. 57/87 Sunday: Patchy morning clouds. Sunny and warm. 56/86 Monday: Patchy morning clouds. Sunny and warm. 56/88 Tuesday: Morning clouds. Sunny in the afternoon. 54/84 Wednesday: Morning clouds. Sunny in the afternoon. 52/82 This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. From willamette-fcst at listsmart.osl.state.or.us Wed Jul 7 11:57:30 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 7 Jul 2010 11:57:30 -0700 Subject: [willamette-fcst] Silverton Hills Forecast - Wed, Jul 07 2010 Message-ID: <8CD18C5BD70D6F4BB2B636295905299C8A13BDC0@WPODFEXCL01.ODF.STATE.OR.US> SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT WED JUL 07 2010 BURN ADVISORY: ...Fire Marshal Conditions are likely this afternoon... Agricultural burning is allowed. Suggested burn times are from now to 7:00pm. Prep burning is not allowed. Propane flaming burning is not allowed. WEATHER DISCUSSION: A strong ridge of high pressure will bring near record warm temperatures to the Willamette Valley today. Skies were sunny across Oregon at midday, with the exception of low clouds advancing northward along the southern and central coast. Most western valley locations had already warmed well into the 80s by late this morning and were 10-15 degrees warmer than 24 hours ago. Salem's record high, of 100 degrees, is within reach this afternoon. The late-morning surface analysis showed a thermal trough extending from southwestern Oregon to the northern Oregon coast. The interior of western Oregon was getting offshore winds, while winds on the central and southern coast had turned onshore. Winds were still offshore along the northern coast, where Astoria was in the mid 80s. In contrast, temperatures were in the mid 50s on the south coast and only in the low 60s along the central coast. The coastal onshore flow will continue to creep northward this afternoon. Winds will stay offshore in the Willamette Valley, helping temperatures approach record highs. Fields are not ready for burning. Salem's high temperature today will be near 98 degrees. Minimum relative humidity this afternoon will be near 17%. Sunset: 8:55 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 93 98 92 Relative Humidity: 22% 17% 21% Surface Wind Direction: 360 360 340 Surface Wind Speed: 9 10 9 Transport Wind Direction: 30 20 30 Transport Wind Speed: 13 17 17 Estimated Mixing Height: 3500 5000 3000 Ventilation Index: 46 85 51 EXTENDED DISCUSSION: The strong ridge of high pressure will continue to bring near record heat to the valley Thursday and Friday with weak onshore flow bring some minor cooling over the weekend. EXTENDED FORECAST: Thursday: Sunny with near record warmth. Light north winds. 62/100 Friday: Sunny and continued hot. Wind: NW 5-10 mph. 63/96 Saturday: Sunny and slightly cooler. Wind: NW 5-15 mph. 57/87 Sunday: Patchy morning clouds. Sunny and warm. 56/86 Monday: Patchy morning clouds. Sunny and warm. 56/88 Tuesday: Morning clouds. Sunny in the afternoon. 54/84 Wednesday: Morning clouds. Sunny in the afternoon. 52/82 This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local Terrain conditions. -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 8 08:59:00 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 8 Jul 2010 08:59:00 -0700 Subject: [willamette-fcst] Willamette Valley - Silverton Hills Field Burning Forecast July 8, 2010 Message-ID: <8CD18C5BD70D6F4BB2B636295905299C8A13BF4C@WPODFEXCL01.ODF.STATE.OR.US> SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT THU JUL 08 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming burning is not allowed. WEATHER DISCUSSION: A strong ridge of high pressure remains over the Pacific Northwest this morning. A strong surface thermal trough shifted just inland overnight and induced an onshore flow onto the immediate coastline. Visible satellite imagery this morning showed low clouds banked up along the entire length of the Oregon coast and most of the Washington coast. Some low cloudiness was trying to penetrate into the coastal range gaps but was not making it past the coast range crest. Skies were sunny over the remainder of Oregon, except for some debris clouds left over from some last night's thunderstorm activity near the California border. Another near record warm day is in store, for the Willamette Valley. The surface thermal trough forecast to remain over the interior of western Oregon through mid-afternoon, then possibly shift eastward to over the Cascades this evening. A weak upper-level trough just off the northern California coastline will continue to circulate enough moisture northward for a chance of afternoon thunderstorms over mainly southern Oregon. A few storms could develop as far north as the central Cascades. Winds in the valley will be mostly northerly today but could turn northwesterly late this afternoon and evening, with some marine air beginning to filter into the valley. TODAY: Sunny and hot. Light north winds this afternoon. High near 99 degrees. Minimum relative humidity will be near 19%. Salem Sunset: 8:55 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 81 94 98 88 Relative Humidity: 38% 25% 22% 30% Surface Wind Direction: 120 350 340 330 Surface Wind Speed: 5 7 7 7 Transport Wind Direction: 120 360 350 340 Transport Wind Speed: 5 5 10 7 Estimated Mixing Height: 1800 3000 3800 1500 Ventilation Index: 9 15 38 10 EXTENDED DISCUSSION: A weak upper-level trough is forecast to push across Oregon Friday with a return of onshore flow cooling temperatures several degrees. There is also an increased chance for thunderstorms over the Cascades. A dry northwesterly flow aloft will prevail for the remainder of the extended forecast period with varying degrees of onshore flow holding temperatures closer to seasonal normals. EXTENDED FORECAST: Friday: Mostly Sunny and continued hot. Slight chance of pm t-storms, mainly near the Cascades. Wind: NW 5-10 mph. 63/94 Saturday: Mostly Sunny and a little cooler. Wind: NW 5-15 mph. 59/87 Sunday: Morning clouds. Sunny in the afternoon. 56/85 Monday: Patchy morning clouds. Sunny in the afternoon. 55/85 Tuesday: Patchy morning clouds. Sunny in the afternoon. 53/82 Wednesday: Morning clouds with afternoon clearing. Cooler. 52/77 Thursday: Brief morning clouds...becoming mostly sunny and warmer. 51/85 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 8 09:56:41 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 08 Jul 2010 11:56:41 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 08 2010 Message-ID: Test Message From willamette-fcst at listsmart.osl.state.or.us Thu Jul 8 11:58:27 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 8 Jul 2010 11:58:27 -0700 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 08 2010 Message-ID: <8CD18C5BD70D6F4BB2B636295905299C8A13C01F@WPODFEXCL01.ODF.STATE.OR.US> SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT THU JUL 08 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming burning is not allowed. WEATHER DISCUSSION: A strong ridge of high pressure remains over the Pacific Northwest, but there are some changes in the weather pattern today. The strong surface thermal trough that was just off the northern Oregon coast on Wednesday has shifted eastward into the Willamette Valley. That has changed the wind-flow pattern from offshore to onshore along the coast with light winds in the Willamette Valley. Midday visible satellite imagery showed the marine low clouds, which briefly penetrated into some of the western coastal range gaps this morning, had backed off to the immediate coastline. Skies were sunny over the remainder of Oregon, except for some shower and thunderstorm activity beginning to build up again across extreme southwestern and south-central Oregon. Midday temperatures were running about 5-8 degrees cooler than 24 hours ago, across the Willamette Valley, and today's forecast high temperature has been lowered a few degrees. A weak upper-level trough, just off the northern California coastline, will continue to circulate enough moisture northward for afternoon showers and thunderstorms over mainly southern Oregon. A few storms could push as far north as the central Cascades, but the convective activity is forecast to stay south and east of the Willamette Valley. The surface thermal trough is forecast to remain over the valley through this afternoon and then shift eastward to over the Cascades this evening. Light winds may turn northwesterly this evening, with some cooler marine air beginning to filter into the Willamette Valley. TODAY: Sunny and hot. Light north winds turning northwesterly this evening. High near 95 degrees. Minimum relative humidity will be near 24%. Salem Sunset: 8:55 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 89 94 86 Relative Humidity: 28% 24% 32% Surface Wind Direction: 350 340 330 Surface Wind Speed: 7 7 7 Transport Wind Direction: 360 350 340 Transport Wind Speed: 5 10 7 Estimated Mixing Height: 3000 3800 1500 Ventilation Index: 15 38 10 EXTENDED DISCUSSION: A weak upper-level trough is forecast to push across Oregon Friday with a return of onshore flow cooling temperatures a few more degrees. There may still be a few thunderstorms over the Cascades, but most of the convective activity should remain well east of the Willamette Valley. A dry northwesterly flow aloft will prevail Saturday through Tuesday with temperatures progressively cooling back to near normal. Increasing onshore flow may bring patchy marine clouds into the Willamette Valley by Sunday morning. The latest long-range models are now showing a more significant trough moving into the region Wednesday and Thursday of next week. That would further cool temperatures and possibly bring some light showers. EXTENDED FORECAST: Friday: Mostly Sunny and a touch cooler. Wind: NW 5-12 mph. 58/92 Saturday: Mostly Sunny but cooler. Wind: NW 5-15 mph. 59/87 Sunday: Patchy morning clouds. Sunny in the afternoon. 56/85 Monday: Patchy morning clouds. Sunny in the afternoon. 55/85 Tuesday: Patchy morning clouds. Sunny in the afternoon. 53/82 Wednesday: Mostly cloudy. Slight chance of showers north. 52/77 Thursday: Mostly cloudy. Chance of showers...mainly north. 52/74 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 8 16:22:05 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 08 Jul 2010 18:22:05 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 08 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT THU JUL 08 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming burning is not allowed. WEATHER DISCUSSION: A strong ridge of high pressure remains over the Pacific Northwest, but there are some changes in the weather pattern today. The strong surface thermal trough that was just off the northern Oregon coast on Wednesday has shifted eastward into the Willamette Valley. That has changed the wind-flow pattern from offshore to onshore along the coast with light winds in the Willamette Valley. Midday visible satellite imagery showed the marine low clouds, which briefly penetrated into some of the western coastal range gaps this morning, had backed off to the immediate coastline. Skies were sunny over the remainder of Oregon, except for some shower and thunderstorm activity beginning to build up again across extreme southwestern and south-central Oregon. Midday temperatures were running about 5-8 degrees cooler than 24 hours ago, across the Willamette Valley, and today?s forecast high temperature has been lowered a few degrees. A weak upper-level trough, just off the northern California coastline, will continue to circulate enough moisture northward for afternoon showers and thunderstorms over mainly southern Oregon. A few storms could push as far north as the central Cascades, but the convective activity is forecast to stay south and east of the Willamette Valley. The surface thermal trough is forecast to remain over the valley through this afternoon and then shift eastward to over the Cascades this evening. Light winds may turn northwesterly this evening, with some cooler marine air beginning to filter into the Willamette Valley. TODAY: Sunny and hot. Light north winds turning northwesterly this evening. High near 95 degrees. Minimum relative humidity will be near 24%. Salem Sunset: 8:55 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 89 94 86 Relative Humidity: 28% 24% 32% Surface Wind Direction: 350 340 330 Surface Wind Speed: 7 7 7 Transport Wind Direction: 360 350 340 Transport Wind Speed: 5 10 7 Estimated Mixing Height: 3000 3800 1500 Ventilation Index: 15 38 10 EXTENDED DISCUSSION: A weak upper-level trough is forecast to push across Oregon Friday with a return of onshore flow cooling temperatures a few more degrees. There may still be a few thunderstorms over the Cascades, but most of the convective activity should remain well east of the Willamette Valley. A dry northwesterly flow aloft will prevail Saturday through Tuesday with temperatures progressively cooling back to near normal. Increasing onshore flow may bring patchy marine clouds into the Willamette Valley by Sunday morning. The latest long-range models are now showing a more significant trough moving into the region Wednesday and Thursday of next week. That would further cool temperatures and possibly bring some light showers. EXTENDED FORECAST: Friday: Mostly Sunny and a touch cooler. Wind: NW 5-12 mph. 58/92 Saturday: Mostly Sunny but cooler. Wind: NW 5-15 mph. 59/87 Sunday: Patchy morning clouds. Sunny in the afternoon. 56/85 Monday: Patchy morning clouds. Sunny in the afternoon. 55/85 Tuesday: Patchy morning clouds. Sunny in the afternoon. 53/82 Wednesday: Mostly cloudy. Slight chance of showers north. 52/77 Thursday: Mostly cloudy. Chance of showers?mainly north. 52/74 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Thu Jul 8 16:22:24 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 08 Jul 2010 18:22:24 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 08 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT THU JUL 08 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming burning is not allowed. WEATHER DISCUSSION: A strong ridge of high pressure remains over the Pacific Northwest, but there are some changes in the weather pattern today. The strong surface thermal trough that was just off the northern Oregon coast on Wednesday has shifted eastward into the Willamette Valley. That has changed the wind-flow pattern from offshore to onshore along the coast with light winds in the Willamette Valley. Midday visible satellite imagery showed the marine low clouds, which briefly penetrated into some of the western coastal range gaps this morning, had backed off to the immediate coastline. Skies were sunny over the remainder of Oregon, except for some shower and thunderstorm activity beginning to build up again across extreme southwestern and south-central Oregon. Midday temperatures were running about 5-8 degrees cooler than 24 hours ago, across the Willamette Valley, and today?s forecast high temperature has been lowered a few degrees. A weak upper-level trough, just off the northern California coastline, will continue to circulate enough moisture northward for afternoon showers and thunderstorms over mainly southern Oregon. A few storms could push as far north as the central Cascades, but the convective activity is forecast to stay south and east of the Willamette Valley. The surface thermal trough is forecast to remain over the valley through this afternoon and then shift eastward to over the Cascades this evening. Light winds may turn northwesterly this evening, with some cooler marine air beginning to filter into the Willamette Valley. TODAY: Sunny and hot. Light north winds turning northwesterly this evening. High near 95 degrees. Minimum relative humidity will be near 24%. Salem Sunset: 8:55 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 89 94 86 Relative Humidity: 28% 24% 32% Surface Wind Direction: 350 340 330 Surface Wind Speed: 7 7 7 Transport Wind Direction: 360 350 340 Transport Wind Speed: 5 10 7 Estimated Mixing Height: 3000 3800 1500 Ventilation Index: 15 38 10 EXTENDED DISCUSSION: A weak upper-level trough is forecast to push across Oregon Friday with a return of onshore flow cooling temperatures a few more degrees. There may still be a few thunderstorms over the Cascades, but most of the convective activity should remain well east of the Willamette Valley. A dry northwesterly flow aloft will prevail Saturday through Tuesday with temperatures progressively cooling back to near normal. Increasing onshore flow may bring patchy marine clouds into the Willamette Valley by Sunday morning. The latest long-range models are now showing a more significant trough moving into the region Wednesday and Thursday of next week. That would further cool temperatures and possibly bring some light showers. EXTENDED FORECAST: Friday: Mostly Sunny and a touch cooler. Wind: NW 5-12 mph. 58/92 Saturday: Mostly Sunny but cooler. Wind: NW 5-15 mph. 59/87 Sunday: Patchy morning clouds. Sunny in the afternoon. 56/85 Monday: Patchy morning clouds. Sunny in the afternoon. 55/85 Tuesday: Patchy morning clouds. Sunny in the afternoon. 53/82 Wednesday: Mostly cloudy. Slight chance of showers north. 52/77 Thursday: Mostly cloudy. Chance of showers?mainly north. 52/74 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Fri Jul 9 08:54:21 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 09 Jul 2010 10:54:21 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Fri, Jul 09 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT FRI JUL 09 2010 BURN ADVISORY: ?State Fire Marshal Conditions may be reached this afternoon due to high temperatures and low relative humidities? Recommended burn times for agricultural burning are from 11:00am to 6:00pm. Prep burning is not allowed. Propane flaming burning is not allowed. WEATHER DISCUSSION: A strong ridge of high pressure remains over the Pacific Northwest this morning. A broad surface thermal trough extends from the Willamette Valley to the Cascades with light winds across the interior of western Oregon. It was a very warm night with valley temperatures staying in the 60s. As a result, mid-morning temperatures are running about 3-8 degrees warmer than 24 hours ago. Once again this morning, visible satellite imagery shows low clouds and fog banked up against the entire length of the Oregon Coast with temperatures there in the low to mid 50s. A very weak upper-level disturbance, just off the northern California coast, is continuing to circulate considerable mid and high-level moisture northward over Oregon. That has combined with daytime heating the past couple of days to produce some fairly potent thunderstorm development over southwestern and south-central Oregon. That will be the case again later today, but the convective activity should stay east and south of the Willamette Valley. The surface thermal trough is forecast to shift into central Oregon this evening, which will initiate a weak marine push into the Willamette Valley. However, sunny skies and very warm air aloft will lift temperatures well into the 90s, before the cooling evening sea breeze kicks in. TODAY: Sunny and continued hot. Light north winds turning northwesterly and increasing this evening. High near 95 degrees. Relative humidities expected to fall below 30% in the mid to late afternoon. Salem Sunset: 8:59 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 82 91 95 85 Relative Humidity: 44% 32% 25% 35% Surface Wind Direction: 360 350 340 300 Surface Wind Speed: 5 7 8 11 Transport Wind Direction: 360 360 350 330 Transport Wind Speed: 4 9 10 12 Estimated Mixing Height: 1500 3200 4000 1500 Ventilation Index: 6 29 40 18 EXTENDED DISCUSSION: A dry northwesterly flow aloft will prevail during the extended forecast period. Weak onshore flow will cool temperatures back into the 80s over the weekend. A stronger upper-level trough is forecast to swing across southern British Columbia Monday, which will increase the onshore flow across western Oregon and cool temperatures back to normal or slightly below. A similar system is forecast to bring another surge of marine air into the valley late Wednesday and Thursday, which will keep temperatures near normal. EXTENDED FORECAST: Saturday: Mostly Sunny but cooler. Wind: NW 5-15 mph. 57/85 Sunday: Mostly Sunny. Wind: NW 5-15 mph. 55/87 Monday: Morning clouds with afternoon clearing. Much cooler. 55/77 Tuesday: Morning clouds. Mostly Sunny in the afternoon. 53/78 Wednesday: Partly cloudy. 52/81 Thursday: Morning clouds. Afternoon clearing. 52/78 Friday: Brief morning clouds. Mostly Sunny in the afternoon. 53/84 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Fri Jul 9 11:55:49 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 09 Jul 2010 13:55:49 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Fri, Jul 09 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT FRI JUL 09 2010 BURN ADVISORY: ?State Fire Marshal Conditions may be reached this afternoon due to high temperatures and low relative humidities? Recommended burn times for agricultural burning are from now to 6:00pm. Prep burning is not allowed. Propane flaming burning is not allowed. MIDDAY WEATHER DISCUSSION: A strong ridge of high pressure remains over the Pacific Northwest. A broad surface thermal trough extends from the Willamette Valley to the Cascades and northeastward across the Columbia Gorge and into central Washington. Temperatures continue to be very warm across the Willamette Valley. Late morning readings were in the upper 70s north and low to mid 80s south. The central and south valley is still running 3-8 degrees warmer than 24 hours ago, but temperatures in the extreme north valley are slightly cooler than at this time yesterday. Low clouds are continuing to hug much of the coastal strip, but some of the beaches are beginning to see the sunshine. Weak onshore flow is keeping coastal temperatures from the upper 50s to mid 60s. A very weak upper-level disturbance, just off the northern California coast, is continuing to circulate considerable mid and high-level moisture northward over mainly the southern half of Oregon. That has combined with daytime heating the past couple of days to produce some fairly potent thunderstorms over southwestern and south-central Oregon. Lightning detection showed over 300 strikes Thursday with the bulk of the activity over Jackson and eastern Douglas Counties. That will be the case again later today, but the convective activity should push slightly further north and east?staying east of the Willamette Valley. The surface thermal trough is forecast to shift into central Oregon this evening, which will open the door for marine air to begin filtering into the Willamette Valley. Before then, valley temperatures should warm well into the 90s, especially south. Sections of the central and south valley may end up warmer today than yesterday, but the extreme north valley will likely be a few degrees cooler. THIS AFTERNOON?S FORECAST: Sunny and continued hot. Light north winds will turn northwesterly and increase this evening. Valley highs today will climb to near 95 degrees. Relative humidities should fall below 30% in the mid to late afternoon. Salem Sunset: 8:59 pm EXTENDED DISCUSSION: A dry northwesterly flow aloft will prevail during the extended forecast period. Weak onshore flow will cool temperatures back into the 80s over the weekend. A stronger upper-level trough is forecast to swing across southern British Columbia Monday, which will increase the onshore flow across western Oregon and cool temperatures back to normal or slightly below normal. A similar system is forecast to bring another surge of marine air into the valley late Thursday, which will keep hold temperatures around normal. EXTENDED FORECAST: Saturday: Mostly Sunny but cooler. Wind: NW 5-15 mph. 57/85 Sunday: Mostly Sunny. Wind: NW 5-15 mph. 55/87 Monday: Morning clouds with afternoon clearing. Breezy and cooler. 55/75 Tuesday: Morning clouds. Mostly Sunny in the afternoon. 53/78 Wednesday: Partly to mostly sunny. 52/81 Thursday: Partly to mostly Sunny. 53/81 Friday: Morning Clouds. Mostly Sunny in the afternoon. 53/80 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Mon Jul 12 08:25:35 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 12 Jul 2010 10:25:35 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Mon, Jul 12 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT MON JUL 12 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 11:00am to 7:00pm. Prep burning is allowed from 11:00am to 5:00pm with a 100 acre limit. Propane flaming is allowed from 11:00am to 5:00pm. WEATHER DISCUSSION: A fairly active upper disturbance for mid July is moving across British Columbia today. This has thickened the marine layer and brought clouds and cooler air into the Willamette Valley. Satellite pictures show a solid cloud deck from about central Douglas County northward through the Willamette Valley and across all of western Washington. The clouds extend at least 200 miles offshore to the west. The morning Salem weather balloon sounding shows the cloud layer fairly thin, extending from about 2200 feet to about 3000 feet. However the surface pressure pattern should continue strong onshore making it difficult for the clouds to burn off. Expect clouds through early afternoon, then partly cloudy skies late afternoon, finally clearing early evening. Salem's high temperature today will be near 75. Relative humidity drops to 50% by 11am. Minimum relative humidity today will be about 36%. The morning sounding showed a strong inversion from 3200 feet to 4200 feet. Temperatures will not warm enough to break this inversion and the maximum mixing height today will be about 3700 feet. Transport winds will be mostly north- northwesterly throughout the day. With the northerly component to transport winds there does not appear to be an opportunity for open field burning today. Sunset tonight: 8:52 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 68 72 75 68 Relative Humidity: 53% 43% 36% 44% Surface Wind Direction: 340 320 320 310 Surface Wind Speed: 9 11 16 15 Transport Wind Direction: 350 340 330 340 Transport Wind Speed: 5 5 12 6 Estimated Mixing Height: 3200 3300 3700 1300 Ventilation Index: 16 16 44 8 EXTENDED DISCUSSION: Low clouds will fill back in tonight and tomorrow morning as another upper disturbance swings through to the north and maintains the moderate to strong onshore flow. As this moves east a little more sunshine is likely tomorrow afternoon. A flat upper ridge moves in Wesnesday that should give more sunshine. The rest of the week should see a flat westerly flow aloft with just minor upper level rippels moving through - the main effect will be areas of morning low clouds with afternoon sunshine and temperatures near or slightly above average. EXTENDED FORECAST: Tuesday: Morning clouds then partly sunny, with a high near 75. NNW wind 5 to 15 mph, with gusts to about 20 mph. Tuesday Night: Mostly cloudy, with a low around 49. Wednesday: Mostly sunny, with a high near 84. Calm wind becoming north-northwest between 7 and 10 mph. Wednesday Night: Mostly clear, with a low around 52. Thursday: Sunny, high 86. Thursday Night: Mostly clear, with a low around 51. Friday: Sunny, high 86. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Mon Jul 12 11:38:34 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 12 Jul 2010 13:38:34 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Mon, Jul 12 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT MON JUL 12 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from now until 7:00pm. Prep burning is allowed from now until 5:00pm with a 50 acre limit. Propane flaming is allowed now until 5:00pm. WEATHER DISCUSSION: A fairly active upper disturbance for mid July is moving across British Columbia today. This thickened the marine layer last night and brought clouds and cooler air into the Willamette Valley. The morning Salem sounding showed temperatures about 10 degrees cooler than yesterday at the same time up to about 3000 feet. As 11am today surface temperatures were running 10 to 15 degrees cooler than 11am yesterday. Late morning satellite pictures show a fairly solid cloud deck from about central Douglas County northward through the Willamette Valley and across most of western Washington. The clouds extend at least 200 miles offshore to the west. The morning sounding showed this cloud layer to be fairly thin, extending from about 2200 feet to about 3000 feet. However the surface pressure pattern should continue strong onshore making it difficult for the clouds to burn off. Pressure gradients as of 11am included: Newport to Salem, 1.1 mb onshore; Salem to Redmond, 7.6 mb onshore for considerable gradient stacking to the east. Expect clouds through early afternoon, then partly cloudy skies late afternoon, finally clearing early evening. Salem's high temperature today will be in the low 70s. Relative humidity reaches 50% shortly after noon. Minimum relative humidity will be near 38% One more item from the morning sounding: it showed a strong inversion from 3200 feet to 4200 feet. Temperatures will not warm enough to break this inversion and the maximum mixing height today will be about 3700 feet. Trajectory models show transport winds will be mostly north-northwesterly throughout the day. With the northerly component to transport winds there does not appear to be an opportunity for open field burning today. Sunset tonight: 8:52 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 67 69 65 Relative Humidity: 49% 42% 47% Surface Wind Direction: 320 330 320 Surface Wind Speed: 10 12 15 Transport Wind Direction: 340 330 340 Transport Wind Speed: 5 12 6 Estimated Mixing Height: 3300 3700 1300 Ventilation Index: 16 44 8 EXTENDED DISCUSSION: Low clouds will fill back in tonight and tomorrow morning as another upper disturbance swings through to the north and maintains the moderate to strong onshore flow. As this moves east a little more sunshine is likely tomorrow afternoon. A flat upper ridge moves in Wesnesday that should give more sunshine. The rest of the week should see a flat westerly flow aloft with just minor upper level rippels moving through - the main effect will be areas of morning low clouds with afternoon sunshine and temperatures near or slightly above average. EXTENDED FORECAST: Tuesday: Partly sunny, with a high near 75. North northwest wind between 5 and 14 mph, with gusts as high as 20 mph. Wednesday: Mostly sunny, with a high near 84. Calm wind becoming north northwest between 7 and 10 mph. Thursday: Sunny, with a high near 86. Friday: Sunny, high 86. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Tue Jul 13 08:27:59 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 13 Jul 2010 10:27:59 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 13 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT TUE JUL 13 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 10:00am to 7:00pm. Prep burning is allowed from 11:00am to 5:00pm with a 50 acre limit. Propane flaming is allowed from 11:00am to 5:00pm. WEATHER DISCUSSION: A fairly deep upper level low is moving eastward across southwest Canada today. A trailing upper level trough will sweep across Washington and Oregon during the day. The associated cooler air mass will keep the mid Willamette Valley cooler than average for this time of year by several degrees. The morning Salem sounding showed a shallow, surface based inversion that should be gone by now and another, stronger inversion aloft from about 4500 to 6300 feet. This inversion will not break and the maximum mixing height today will be about 5300 feet. While the morning sounding showed temperatures in the lower atmosphere had cooled another 5 degrees or so since yesterday morning, increased sunshine today should push temperatures a couple of degrees warmer than yesterday by afternoon. Salem's high temperature today will be near 76. Relative humidity drops to 50% by 11am. Minimum relative humidity 33%. The ODF morning surface analysis showed high pressure nosing into NW Oregon and a well developed thermal trough in the central valley of California. Gradients were rather flat west to east across the valley, but there is a strong north to south gradient toward the thermal trough. This will give an unfavorable northerly wind to the region throughout the day. Both the RUC and NAM model trajectory forecasts show any smoke from the Silverton Hills region headed toward central Lane County. Open field burning opportunities are not likely this afternoon. Sunset tonight: 8:52 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 64 71 75 73 Relative Humidity: 52% 39% 34% 38% Surface Wind Direction: 360 340 350 330 Surface Wind Speed: 9 9 10 10 Transport Wind Direction: 360 010 010 350 Transport Wind Speed: 5 7 9 4 Estimated Mixing Height: 4800 5000 5300 1000 Ventilation Index: 24 35 48 4 EXTENDED DISCUSSION: Weak ridging aloft will develop on Wednesday, replaced by a weak trough aloft late in the week. The net effect should be almost nil in the Willamette Valley with mostly sunny weather and temperatures a few degrees above average. Transport winds will be generally northerly with occasional shifts to northwesterly in the afternoon but prospects for favorable transport winds are small through the weekend. Long range charts do show more westerly flow in the transport region next Monday. EXTENDED FORECAST: Wednesday: Sunny and warmer. 84. Calm wind becoming N 8-12 mph. Wednesday Night: Mostly clear, low 52. Thursday: Sunny. 86. Wind becoming NW 6-9 mph. Friday: Sunny, with a high near 86. Saturday: Sunny, with a high near 87. Sunday: Sunny, with a high near 85. Monday: Sunny, with a high near 85. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Tue Jul 13 11:29:18 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 13 Jul 2010 13:29:18 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 13 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT TUE JUL 13 2010 BURN ADVISORY: Recommended burn times for agricultural burning are now until 7:00pm. Prep burning is allowed up until 5:00pm with a 50 acre limit. Propane flaming is allowed up until to 5:00pm. WEATHER DISCUSSION: A fairly deep upper level low is moving eastward across southwest Canada today. A trailing upper level trough sweeping across Washington and Oregon has brought some cloudiness to the northern Willamette Valley. Temperatures will be cooler than average for this time of year by several degrees. The morning Salem sounding showed an inversion aloft from about 4500 to 6300 feet. This inversion will not break today and the maximum mixing height this afternoon will be about 5300 feet. While the morning sounding showed temperatures in the lower atmosphere had cooled another 5 degrees since yesterday morning, increased sunshine today should push maximum temperatures a couple of degrees higher today. Salem is still on track for a high temperature near 76 with mostly sunny skies. Minimum relative humidity today will be 33%. The ODF late morning surface analysis continues to show high pressure nosing into NW Oregon and a thermal trough in the central valley of California. Pressure gradients as of 11am included: Newport to Salem, 0.9 mb onshore; Salem to Redmond, 4.8 mb onshore; for a total of 5.7mb on shore. There is considerable gradient stacking to the east. This is all showing up as an unfavorable northerly transport wind. Both the RUC and NAM model trajectory forecasts continue to show any smoke from the Silverton Hills region headed toward central Lane County. Open field burning opportunities are not likely this afternoon. Sunset tonight: 8:52 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 68 71 70 Relative Humidity: 39% 36% 41% Surface Wind Direction: 330 340 330 Surface Wind Speed: 8 11 11 Transport Wind Direction: 010 010 350 Transport Wind Speed: 7 9 4 Estimated Mixing Height: 5000 5300 1000 Ventilation Index: 35 48 4 EXTENDED DISCUSSION: Weak ridging aloft will develop on Wednesday, replaced by a weak trough aloft late in the week. The net effect should be almost nil in the Willamette Valley with mostly sunny weather and temperatures a few degrees above average. Transport winds will be generally northerly with occasional shifts to northwesterly in the afternoon but prospects for favorable transport winds are small through the weekend. Long range charts do show more westerly flow in the transport region next Monday. EXTENDED FORECAST: Wednesday: Sunny and warmer. 84. Calm wind becoming N 8-12 mph. Wednesday Night: Mostly clear, low 52. Thursday: Sunny. 86. Wind becoming NW 6-9 mph. Friday: Sunny, with a high near 86. Saturday: Sunny, with a high near 87. Sunday: Sunny, with a high near 85. Monday: Sunny, with a high near 85. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Wed Jul 14 08:47:42 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 14 Jul 2010 10:47:42 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Wed, Jul 14 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT WED JUL 14 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 10:00am to 7:00pm. Prep burning is allowed from 11:00am to 5:00pm with a 50 acre limit. Propane flaming is allowed from 11:00am to 5:00pm. WEATHER DISCUSSION: Clear skies last night led to chilly temperatures this morning. Satellite pictures show the Pacific Northwest is virtually cloud free this morning. The morning Salem sounding showed the air mass warmer compared to yesterday at the same time at all levels. In particular, temperatures are about 15 degrees warmer between 3000 and 5000 feet. Maximum temperatures today should be quite a bit warmer than yesterday. Salem's high temperature today will be near 85 with sunny skies and northerly surface winds. Relative humidity drops to 50% by 11am and the minimum relative humidity should drop to 26%. A surface temperature in the mid 80's will produce a maximum mixing height of about 5000 feet today. The morning ODA surface analysis shows that the gradient stacking to the east is gone but a relatively strong northerly gradient has set up across the state. The pressure difference from Newport to Redmond is nearly flat while the Portland to Medford gradient is about 4mb. A thermal trough extends from the central Valley of California into extreme southwest Oregon. This is giving a northerly transport to the Willamette Valley that will continue all day. Model trajectory forecasts show potential smoke from the Silverton Hills area headed toward Eugene. Salem sunset tonight: 8:51 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 68 79 85 80 Relative Humidity: 51% 34% 26% 35% Surface Wind Direction: 010 360 010 360 Surface Wind Speed: 8 10 14 10 Transport Wind Direction: 010 360 360 360 Transport Wind Speed: 9 10 15 6 Estimated Mixing Height: 3000 4700 5000 1000 Ventilation Index: 27 47 75 6 EXTENDED DISCUSSION: The Pacific Northwest is in a fairly normal summertime weather pattern and no extremes of weather are likely for the next few days. Upper air charts show a broad flat ridge today, a zonal or west-to-east flow aloft tomorrow, and a broad shallow trough Friday. None of these features will have much effect on Willamette Valley weather other than to produce sunny skies and temperatures near or above average. Maximum mixing heights will gradually lower during the rest of the week but should remain fairly high. There may be a bit of a marine push Friday for a potential burning opportunity and long range charts are still showing a more westerly transport flow next Monday. Next week looks cooler with an upper level trough over the region. EXTENDED FORECAST: Thursday: Sunny, with a high near 87. Calm wind becoming N 7-10 mph. Thursday Night: Mostly clear, with a low around 51. NNE wind 5-10. Friday: Sunny, with a high near 83. NNW wind 5-15 mph. Saturday: Sunny, 85. Sunday: Sunny, 82. Monday: Mostly sunny, 80. Tuesday: Sunny, 81. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Wed Jul 14 11:29:29 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 14 Jul 2010 13:29:29 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Wed, Jul 14 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT WED JUL 14 2010 BURN ADVISORY: Recommended burn times for agricultural burning are now up until to 7:00pm. Prep burning is allowed up until 5:00pm with a 50 acre limit. Propane flaming is allowed up until to 5:00pm. WEATHER DISCUSSION: As of 11am temperatures are running 5 to 7 degrees warmer than yesterday at the same time in the Willamette Valley. Bright sunshine and a high sun angle should easily push temperatures into the mid 80's this afternoon. The late morning ODF surface analysis shows a thermal trough in the central valley of California with weak high pressure to the north over the Puget Sound. The west to east gradient (Newport to Redmond) is nearly flat. The north to south gradient (Portland to Medford) has dropped to about 3.5mb but is still enough to keep surface and transport winds northerly through the Willamette Valley. The latest trajectory forecast from the RUC model continue to show any smoke from the Silverton Hills headed toward Eugene and central Lane County. Expect total sunshine this afternoon in the central Willamette Valley. Salem's high temperature today will be near 84 and the minimum relative humidity will be about 27%. Winds will be northerly about 8-12mph. Sunset tonight for Salem: 8:51 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 78 84 80 Relative Humidity: 34% 27% 35% Surface Wind Direction: 360 360 360 Surface Wind Speed: 9 12 9 Transport Wind Direction: 360 360 360 Transport Wind Speed: 10 15 6 Estimated Mixing Height: 4700 5000 1000 Ventilation Index: 47 75 6 EXTENDED DISCUSSION: The Pacific Northwest is in a fairly normal summertime weather pattern and no extremes of weather are likely for the next few days. Upper air charts show a broad flat ridge today, a zonal or west-to-east flow aloft tomorrow, and a broad shallow trough Friday. None of these features will have much effect on Willamette Valley weather other than to produce sunny skies and temperatures near or above average. Maximum mixing heights will gradually lower during the rest of the week but should remain fairly high. There are still indications of a more westerly transport flow next Monday. Next week looks cooler with an upper level trough developing over the region. EXTENDED FORECAST: Thursday: Sunny, with a high near 88. Winds calm becoming N 7-10 mph. . Friday: Sunny, with a high near 83. NNW 5-15 and gusty. Saturday: Mostly sunny, 85. Sunday: Sunny, 82. Monday: Mostly sunny, 80. Tuesday: Sunny, 81. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Thu Jul 15 08:54:51 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 15 Jul 2010 10:54:51 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 15 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT THU JUL 15 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is allowed from 12:00pm to 2:00pm with a 50 acre limit. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: Skies were sunny this morning across the interior of Oregon and Washington with high pressure still in control of the weather pattern. Visible satellite imagery showed low clouds along the entire coastal strip, with pressure gradients beginning to turn more onshore. Temperatures across the Willamette Valley are running about 5-10 degrees warmer than 24 hours ago. The air aloft is also warmer than yesterday, so mixing heights will likely not reach 3000 feet until the afternoon. A weak upper-level trough is forecast to move across southern British Columbia today and flatten the broad ridge of high pressure over the Pacific Northwest. That will shift the surface thermal trough, which stretched from central Washington to southwestern Oregon this morning, east of the Oregon Cascades. A northwesterly marine push is forecast this evening, which should cap high temperatures in the northern Willamette Valley in the mid to upper 80s (similar to Wednesday). Highs in the south valley will likely approach 90 degrees. TODAY?S FORECAST: Sunny and warm. Light north winds turning northwesterly and increasing by this evening to 5-15 mph. Salem's high temperature today will be near 86 degrees. Relative humidity drops to 50% by 10am with a minimum of 29%. Sunset tonight: 8:56 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 76 83 86 78 Relative Humidity: 45% 36% 29% 39% Surface Wind Direction: 010 360 360 320 Surface Wind Speed: 7 7 8 9 Transport Wind Direction: 010 360 340 330 Transport Wind Speed: 8 8 8 12 Estimated Mixing Height: 2000 3000 4000 1500 Ventilation Index: 16 24 32 18 EXTENDED DISCUSSION: A weak upper-level trough is forecast to carve out over the Pacific Northwest with increasing onshore flow and cooler temperatures. Conditions appear as if they will remain dry with the exception of possible morning drizzle, mainly from the coast range westward. EXTENDED FORECAST: Friday: Sunny but cooler. High near 83. Wind: NW 5-15 mph. Friday Night: Increasing clouds. Low near 51. Evening NW wind 5-15 mph decreasing overnight. Saturday: Mostly sunny. High near 80. Wind: NW 5-15 mph in the afternoon. Saturday Night: Mostly cloudy. Low near 51. Sunday: Morning clouds, then mostly sunny. High near 79. Monday: Morning clouds, then partly sunny. High near 77. Tuesday: Morning clouds, then partly sunny. High near 77. Wednesday: Morning clouds, then partly sunny. High near 78. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Thu Jul 15 11:56:51 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 15 Jul 2010 13:56:51 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 15 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT THU JUL 15 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is allowed from 12:00pm to 2:00pm with a 50 acre limit. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: Late-morning visible satellite imagery showed low clouds continuing to blanket the immediate coastline, from Washington southward to about Newport. The low clouds had backed off from the southern Oregon Coast but continued to cover the offshore coastal waters. That is an indication of increasing onshore flow, in response to a weak upper-level disturbance cutting across southern British Columbia. The surface thermal trough is continuing to drift eastward with onshore pressure gradients increasing from Newport to Salem (now 2.5 mb) and turning onshore from Salem to Redmond (0.5 mb). Those onshore pressure gradients should further increase this afternoon with a favorable gradient-stacking pattern for eastward smoke evacuation. Temperatures are running about 3 degrees warmer, than 24 hours ago, in the north valley and up to 7 degrees warmer across the central and south valley. However, the air aloft is also warmer than yesterday, so mixing heights will likely not exceed about 4000 feet today. The thermal trough is forecast to shift east of the Cascades later this afternoon, which will initiate a northwesterly marine push this evening. That will likely hold maximum temperatures in the 80s, which should cap high temperatures in the northern Willamette Valley in the mid to upper 80s across the north valley, but the south valley may hit the 90 degree mark. FORECAST: Sunny and warm this afternoon, with a high temperature in the upper 80s. Surface winds N 5-10 mph, becoming NW 5-15 mph late this afternoon and evening. Transport winds N 8 mph, becoming NW 10 mph late this afternoon and evening. The maximum mixing height should climb to near 4000 feet later this afternoon, with the ventilation index rising to near 40. The minimum relative humidity will be near 29%. Salem?s sunset tonight: 8:56 pm EXTENDED DISCUSSION: An upper-level trough is forecast strengthen over the Pacific Northwest during the extended forecast period. Increasing onshore flow will cool temperatures to near normal Friday and to below normal over the weekend and much of next week. There is even a threat of showers by the middle of next week, mainly north and along the coast. EXTENDED FORECAST: Friday: Sunny but cooler. High near 83. Wind: NW 5-15 mph. Friday Night: Increasing clouds. Low near 51. Evening NW wind 5-15 mph decreasing overnight. Saturday: Mostly sunny. High near 80. Wind: NW 5-15 mph in the afternoon. Saturday Night: Mostly cloudy. Low near 51. Sunday: Morning clouds, then mostly sunny. High near 79. Monday: Morning clouds, then partly sunny. High near 77. Tuesday: Mostly cloudy. Slight chance of showers. High near 75. Wednesday: Mostly cloudy. Chance of showers. High near 72. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Fri Jul 16 08:53:38 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 16 Jul 2010 10:53:38 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Fri, Jul 16 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT FRI JUL 16 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 6:00pm. Prep burning is allowed from 12:00pm to 2:00pm with a 50 acre limit. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: A weak upper-level trough is moving across southern British Columbia and initiated a weak marine push into western Washington and northwestern Oregon Thursday evening. Temperatures across the Willamette Valley are running 5-10 degrees cooler than 24 hours ago, with the morning sounding showing several degrees of cooling from the surface up to about 8000 feet. Visible satellite imagery confirmed that marine low clouds penetrated across most of western Washington overnight and also made it up the Columbia River into the northern Willamette Valley. A few low clouds were making as far south as the Silverton Hills at mid-morning. There may yet be some increase in the marine clouds, before daytime heating acts to break up the marine deck later this morning. The air aloft is still warm, so mixing heights will be slow to climb today. The surface analysis shows the thermal trough extending from eastern Washington across central Oregon and into southwestern Oregon. Cool marine air continues to poor into the Willamette Valley, with considerable gradient-stacking developing across western Oregon. As the upper-level trough pushes eastward, westerly winds aloft will maintain the low-level onshore flow across northwestern Oregon. Daytime heating will promote an afternoon sea breeze, which should turn transport winds from northerly to northwesterly. It is uncertain if the significant morning gradient-stacking can be overcome enough for open burning later this afternoon, but conditions look favorable for early afternoon prep burning. TODAY?S FORECAST: Sunny but cooler. After reaching 89 degrees on Thursday, Salem's high temperature today will be near 83 degrees. The mixing height will climb to 3000 feet in the early afternoon with a maximum near 4000 feet around 5 p.m. Surface winds will be north at 5-10 mph this morning, becoming NW 5-15 mph this afternoon and evening. Transport winds will be north at 10 mph this morning, becoming NW 10-15 mph in the late afternoon and evening. Relative humidity will drop to 50% by 11am and to near 30% this afternoon. Salem's sunset tonight: 8:55 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 69 78 82 73 Relative Humidity: 47% 36% 30% 43% Surface Wind Direction: 360 350 340 320 Surface Wind Speed: 9 9 10 12 Transport Wind Direction: 360 360 340 310 Transport Wind Speed: 10 10 12 15 Estimated Mixing Height: 2000 3200 4000 1500 Ventilation Index: 20 32 48 22 EXTENDED DISCUSSION: A weak upper-level trough will maintain a typical summer-time pattern over the weekend with morning clouds giving way to afternoon sunshine and near-normal temperatures. The trough is forecast to strengthen early next week with the onshore flow possibly becoming strong enough to produce areas of morning drizzle or light showers. Otherwise dry conditions should prevail, but temperatures will cool to below normal with considerable marine low clouds. The trough is forecast to back away from the coastline by late next week with southwesterly flow aloft and temperatures returning to normal. The marine layer may be too deep for open burning, during much of the extended period, but there should be opportunities for prep burning. EXTENDED FORECAST: Saturday: Morning clouds, then mostly sunny. 50/80 Sunday: Morning clouds, then mostly sunny. 50/77 Monday: Morning clouds, then partly sunny. 49/79 Tuesday: Morning clouds, then partly sunny. 51/77 Wednesday: Morning clouds, then partly sunny. 51/76 Thursday: Brief morning clouds, then mostly sunny. 52/82 Friday: Mostly sunny. 54/85 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Fri Jul 16 11:55:30 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 16 Jul 2010 13:55:30 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Fri, Jul 16 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT FRI JUL 16 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from now to 6:00pm. Prep burning is allowed from now to 2:00pm with a 50 acre limit. Propane flaming is allowed from now to 5:00pm. WEATHER DISCUSSION: A weak upper-level trough, cutting across southern British Columbia, has induced an onshore flow into western Oregon. Areas of morning low clouds, across northwestern Oregon, were giving way to sunshine except for over the extreme northwest corner of the state. The remainder of Oregon had sunny skies. Morning low clouds were also beginning to give way to sunshine across western Washington. Late-morning valley temperatures are running 5-10 degrees cooler than 24 hours ago with most locations still in the 60s. The morning sounding also showed several degrees of cooling aloft, up to about 8000 feet. However, the air aloft is still relatively warm, so mixing heights will be slow to rise today. The surface analysis shows the thermal trough extending from eastern Washington, across central Oregon, to southwestern Oregon. Surface winds are generally northerly across the Willamette Valley, with considerable gradient-stacking between Salem and Redmond. As the upper-level trough pushes eastward, westerly winds aloft will maintain the low-level onshore flow across northwestern Oregon. Daytime heating will promote an afternoon sea breeze, which should turn transport winds from northerly to northwesterly. The significant gradient-stacking will not likely be overcome this afternoon, but conditions look favorable for limited early afternoon prep burning. TODAY?S FORECAST: Sunny but cooler. After reaching 89 degrees on Thursday, Salem's high temperature today will be near 82 degrees. The mixing height will climb to 3000 feet in the early afternoon with a maximum near 4000 feet around 5 p.m. Surface winds will be north at 8-15 mph early this afternoon, becoming NW 10-15 mph late this afternoon and evening. Northerly transport winds will also becoming NW at 10-15 mph in the late afternoon and evening. Relative humidity will drop to around 35% this afternoon. Salem's sunset tonight: 8:55 pm EXTENDED DISCUSSION: A weak upper-level trough will maintain a typical summer-time pattern over the weekend with morning clouds giving way to afternoon sunshine and near-normal temperatures. The trough is forecast to strengthen early next week with the onshore flow possibly becoming strong enough to produce areas of morning drizzle or light showers. Otherwise dry conditions should prevail, but temperatures will cool to below normal with considerable marine low clouds. The trough is forecast to back away from the coastline by late next week with southwesterly flow aloft and temperatures returning to normal. The deep marine layer may create too much gradient-stacking for open burning, during much of the extended period, but there should be opportunities for limited prep burning. EXTENDED FORECAST: Saturday: Morning clouds, then mostly sunny. 50/80 Sunday: Morning clouds, then mostly sunny. 50/77 Monday: Morning clouds, then partly sunny. 49/79 Tuesday: Morning clouds, then partly sunny. 51/77 Wednesday: Morning clouds, then partly sunny. 51/76 Thursday: Brief morning clouds, then mostly sunny. 52/82 Friday: Mostly sunny. 54/85 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Wed Jul 14 08:28:29 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 14 Jul 2010 10:28:29 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Wed, Jul 14 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT WED JUL 14 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 10:00am to 7:00pm. Prep burning is allowed from 11:00am to 5:00pm with a 50 acre limit. Propane flaming is allowed from 11:00am to 5:00pm. WEATHER DISCUSSION: Clear skies last night led to chilly temperatures this morning. Satellite pictures show the Pacific Northwest is virtually cloud free this morning. The morning Salem sounding showed the air mass warmer compared to yesterday at the same time at all levels. In particular, temperatures are about 15 degrees warmer between 3000 and 5000 feet. Maximum temperatures today should be quite a bit warmer than yesterday. Salem's high temperature today will be near 85 with sunny skies and northerly surface winds. Relative humidity drops to 50% by 11am and the minimum relative humidity should drop to 26%. A surface temperature in the mid 80's will produce a maximum mixing height of about 5000 feet today. The morning ODA surface analysis shows that the gradient stacking to the east is gone but a relatively strong northerly gradient has set up across the state. The pressure difference from Newport to Redmond is nearly flat while the Portland to Medford gradient is about 4mb. A thermal trough extends from the central Valley of California into extreme southwest Oregon. This is giving a northerly transport to the Willamette Valley that will continue all day. Model trajectory forecasts show potential smoke from the Silverton Hills area headed toward Eugene. Salem sunset tonight: 8:51 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 68 79 85 80 Relative Humidity: 51% 34% 26% 35% Surface Wind Direction: 010 360 010 360 Surface Wind Speed: 8 10 14 10 Transport Wind Direction: 010 360 360 360 Transport Wind Speed: 9 10 15 6 Estimated Mixing Height: 3000 4700 5000 1000 Ventilation Index: 27 47 75 6 EXTENDED DISCUSSION: The Pacific Northwest is in a fairly normal summertime weather pattern and no extremes of weather are likely for the next few days. Upper air charts show a broad flat ridge today, a zonal or west-to-east flow aloft tomorrow, and a broad shallow trough Friday. None of these features will have much effect on Willamette Valley weather other than to produce sunny skies and temperatures near or above average. Maximum mixing heights will gradually lower during the rest of the week but should remain fairly high. There may be a bit of a marine push Friday for a potential burning opportunity and long range charts are still showing a more westerly transport flow next Monday. Next week looks cooler with an upper level trough over the region. EXTENDED FORECAST: Thursday: Sunny, with a high near 87. Calm wind becoming N 7-10 mph. Thursday Night: Mostly clear, with a low around 51. NNE wind 5-10. Friday: Sunny, with a high near 83. NNW wind 5-15 mph. Saturday: Sunny, 85. Sunday: Sunny, 82. Monday: Mostly sunny, 80. Tuesday: Sunny, 81. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Mon Jul 19 08:32:32 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 19 Jul 2010 10:32:32 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Mon, Jul 19 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT MON JUL 19 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: Typical mid-July weather is on the menu for today in the Willamette Valley. Upper level flow is west-northwesterly behind an upper level disturbance that pushed across southern Alberta last night. Low level flow is onshore with a pressure gradient of about 4.5 millibars between the coast and central Oregon. Satellite pictures show marine clouds covering all of the Willamette Valley this morning. Just one aircraft report available so far today from 8 miles north of Eugene and it indicates the top of the overcast layer there is about 2200 feet. The morning Salem sounding shows the tops of the clouds are at about 2800 feet in the mid valley. In either case the clouds shoud break up this afternoon for sunshine and temperatures in the mid to upper 70's - just a few degrees below average. For Salem and the Silverton Hills expect morning clouds, afternoon sunshine and a high temperature of 78. Minimum Relative humidity drops to 50% by noon and the minimum relative humidity today will be 36%. Sunset tonight: 8:47 pm. The morning Salem sounding showed a temperature profile very similar to yesterday morning. Model forecasts indicate slight warming aloft during the day today. Modifying the sounding based on this warming and using a high of 78 gives a maximum mixing height of 3500 feet by late afternoon, but it will be at least mid-afternoon before the mixing height gets above 3000 feet. Transport winds today will stay northerly and model smoke trajectory forecasts indicate mid-Marion county smoke would head south toward Eugene. THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 63 71 77 74 Relative Humidity: 58% 44% 36% 43% Surface Wind Direction: 010 360 360 330 Surface Wind Speed: 8 9 11 10 Transport Wind Direction: 010 010 010 010 Transport Wind Speed: 5 10 10 13 Estimated Mixing Height: 1900 2100 3500 500 Ventilation Index: 10 21 35 6 EXTENDED DISCUSSION: Another upper level disturbance develops and moves in from the northwest tomorrow. This will serve to deepen the marine layer Tuesday makeing for a slower burn-off of clouds. This disturbance pulls out Wednesday with a northwesterly flow aloft developing. This should give more afternoon sun and warmer temperatures. Models then indicate broad, flat ridging through the rest of the week for dry weather and temperatures near or slightly above average. The pattern favors persistent northerly transport winds and burning opportunities are not likely. EXTENDED FORECAST: Tuesday: Morning clouds then partly sunny, high 80. NNW wind between 5 and 9 mph. Tuesday Night: Mostly cloudy, low 52. Wind NNW 6-10 decreasing. Wednesday: Mostly sunny, with a high near 83. Light winds early, becoming NW 8-12 with higher gusts. Wednesday Night: Partly cloudy, with a low around 52. Thursday: Mostly sunny, with a high near 80. Friday: Mostly sunny, 83. Saturday: Mostly sunny, 82. Sunday: Mostly sunny, 83. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Mon Jul 19 11:45:24 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 19 Jul 2010 13:45:24 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Mon, Jul 19 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT MON JUL 19 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from now until 7:00pm. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: Satellilte pictures show the clouds in the Wilamette Valley are breaking up and the Silverton Hills area of Marion County cloud free as of late morning. Low level flow continues onshore. Pressure gradients as of 11am included: Newport to Salem, 1.0 mb onshore; Salem to Redmond, 3.7 mb onshore for a total onshore gradient Newport to Redmond of 4.7 millibars. The Portland to Medford gradient is 5.3 mb northerly and that is causing the northerly transport winds in the valley. With sunshine finally breaking out in the Salem area pressures will drop relative to the coast and the gradient stacking to the east issue may improve this afternoon, but the north to south gradient across the state will continue and no wind switch to westerly is likely this afternoon. Expect sunshine today. Salem's high temperature today will be near 78 and the minimum relative humidity should be 36%. Sunset tonight: 8:47 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 71 77 72 Relative Humidity: 44% 37% 44% Surface Wind Direction: 350 010 340 Surface Wind Speed: 9 10 11 Transport Wind Direction: 010 010 010 Transport Wind Speed: 10 10 13 Estimated Mixing Height: 2100 3500 500 Ventilation Index: 21 35 6 EXTENDED DISCUSSION: Another upper level disturbance develops and moves in from the northwest tomorrow. This will serve to deepen the marine layer Tuesday makeing for a slower burn-off of clouds. This disturbance pulls out Wednesday with a northwesterly flow aloft developing. This should give more afternoon sun and warmer temperatures. Models then indicate broad, flat ridging through the rest of the week for dry weather and temperatures near or slightly above average. The pattern favors persistent northerly transport winds and burning opportunities are not likely. EXTENDED FORECAST: Tuesday: Morning clouds then partly sunny, high 80. NNW wind between 5 and 9 mph. Tuesday Night: Mostly cloudy, low 52. Wind NNW 6-10 decreasing. Wednesday: Mostly sunny, with a high near 83. Light winds early, becoming NW 8-12 with higher gusts. Wednesday Night: Partly cloudy, with a low around 52. Thursday: Mostly sunny, with a high near 80. Friday: Mostly sunny, 83. Saturday: Mostly sunny, 82. Sunday: Mostly sunny, 83. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Tue Jul 20 08:29:59 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 20 Jul 2010 10:29:59 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 20 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT TUE JUL 20 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is allowed from 2:00pm to 5:00pm with a 50 acre limit. Propane flaming is allowed from 2:00pm to 5:00pm. WEATHER DISCUSSION: An upper level short wave is looking a little stronger than it did yesterday and moving down the BC coastline this morning. This may be strong enough to bring the winds around enough to provide a burning opportunity late this afternoon. (This may, however, be a moot point if there are no fields ready to burn.) Growers should make sure that any fields that are ready are known to ODA. Morning satelllite pictures show low clouds in much of the Willamette Valley but they are not as thick or as extensive as yesterday. The air mass is slightly warmer this morning and with some sunshine this afternoon after the burn-off look for temperatures to be up a few degrees from yesterday. The mid Willamette Valley will see morning clouds, clearing by about noon and high temperatures in the low 80's. Salem's high temperature today will be near 82. Relative humidity drops to 50% by 11am. Minimum relative humidity today will be 32%. Winds will be northerly, shifting to northwesterly late this afternoon or early this evening. Gradient stacking to the east is not as strong today as past couple of days, and as valley temperatures warm, valley pressures will drop giving a more favorable west to east gradient profile this afternoon. As of 8am this morning the Newport to Salem gradient was 1.4mb while the Salem to Redmond gradient was 2.9mb. Careful monitoring of pibals, pressure gradients, and surface winds tell the story this afternoon. Sunset tonight: 8:46 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 68 77 82 75 Relative Humidity: 51% 37% 32% 41% Surface Wind Direction: 010 350 340 300 Surface Wind Speed: 7 7 10 10 Transport Wind Direction: 360 350 340 290 Transport Wind Speed: 6 8 8 10 Estimated Mixing Height: 1800 3200 4800 1000 Ventilation Index: 11 26 38 10 EXTENDED DISCUSSION: The westerly or west-northwesterly flow pattern aloft will continue until about Friday when we will see a transition to a southwesterly flow aloft with a weak trough off the California coast and a ridge over the western United States. This should get the Willamette Valley out of a persistent north wind regime and potentially open up some burn opportunities next week. EXTENDED FORECAST: Wednesday: Cloudy early then clearing slowly. High 84. Light winds early then NW 5-8mph. Wednesday Night: Partly cloudy, 53. Thursday: Mostly sunny. 80. Wind becoming WNW 8-12. Potential burn opportunity. Friday: Mostly sunny, 88. Saturday: Mostly sunny, 88. Sunday: Mostly sunny, 83. Monday: Mostly sunny, 83. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Tue Jul 20 11:32:18 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 20 Jul 2010 13:32:18 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 20 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT TUE JUL 20 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is allowed from 2:00pm to 5:00pm with a 50 acre limit. Propane flaming is allowed from 2:00pm to 5:00pm. WEATHER DISCUSSION: An upper level disturbance is deepening along the southern British Columbia coastline today. This has produced some high clouds across portions of Washington and should help turn winds in the Willamette Valley a little more northwesterly late this afternoon. Satellite pictures show most of the clouds in the Valley are east of the Willamette river as of late morning. In addition, low marine clouds are banked up against the north coast and into some of the coastal valleys. Any clouds still covering the Silverton Hills should burn off within the next hour or so for a sunny afternoon. Temperatures should reach into the low 80's with Salem's high temperature near 82. Minimum relative humidity today will be 32%. Winds will be northerly, shifting to northwesterly late this afternoon or early this evening. Gradient stacking to the east has actually increased during the morning. As of 11am this morning the Newport to Salem gradient was 1.3mb while the Salem to Redmond gradient was 3.9mb. However, as valley temperatures warm, valley pressures will drop giving a more favorable west to east gradient profile this afternoon. Today is a potential burn day if the winds do indeed shift to more northwesterly. However, it appears no fields are ready to be put to flame. We will monitor pressure gradients and surface winds to confirm any wind shift. Sunset tonight: 8:46 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 69 75 70 Relative Humidity: 51% 40% 51% Surface Wind Direction: 340 340 300 Surface Wind Speed: 8 10 11 Transport Wind Direction: 350 340 290 Transport Wind Speed: 8 8 10 Estimated Mixing Height: 3200 4800 1000 Ventilation Index: 26 38 10 EXTENDED DISCUSSION: The westerly or west-northwesterly flow pattern aloft will continue until about Friday when we will see a transition to a southwesterly flow aloft with a weak trough off the California coast and a ridge over the western United States. This should get the Willamette Valley out of a persistent north wind regime and potentially open up some burn opportunities next week. EXTENDED FORECAST: Wednesday: Cloudy early then clearing slowly. High 84. Light winds early then NW 5-8mph. Wednesday Night: Partly cloudy, 53. Thursday: Mostly sunny. 80. Wind becoming WNW 8-12. Potential burn opportunity. Friday: Mostly sunny, 88. Saturday: Mostly sunny, 88. Sunday: Mostly sunny, 83. Monday: Mostly sunny, 83. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Tue Jul 20 11:32:43 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 20 Jul 2010 13:32:43 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 20 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 AM PDT TUE JUL 20 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is allowed from 2:00pm to 5:00pm with a 50 acre limit. Propane flaming is allowed from 2:00pm to 5:00pm. WEATHER DISCUSSION: An upper level disturbance is deepening along the southern British Columbia coastline today. This has produced some high clouds across portions of Washington and should help turn winds in the Willamette Valley a little more northwesterly late this afternoon. Satellite pictures show most of the clouds in the Valley are east of the Willamette river as of late morning. In addition, low marine clouds are banked up against the north coast and into some of the coastal valleys. Any clouds still covering the Silverton Hills should burn off within the next hour or so for a sunny afternoon. Temperatures should reach into the low 80's with Salem's high temperature near 82. Minimum relative humidity today will be 32%. Winds will be northerly, shifting to northwesterly late this afternoon or early this evening. Gradient stacking to the east has actually increased during the morning. As of 11am this morning the Newport to Salem gradient was 1.3mb while the Salem to Redmond gradient was 3.9mb. However, as valley temperatures warm, valley pressures will drop giving a more favorable west to east gradient profile this afternoon. Today is a potential burn day if the winds do indeed shift to more northwesterly. However, it appears no fields are ready to be put to flame. We will monitor pressure gradients and surface winds to confirm any wind shift. Sunset tonight: 8:46 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 69 75 70 Relative Humidity: 51% 40% 51% Surface Wind Direction: 340 340 300 Surface Wind Speed: 8 10 11 Transport Wind Direction: 350 340 290 Transport Wind Speed: 8 8 10 Estimated Mixing Height: 3200 4800 1000 Ventilation Index: 26 38 10 EXTENDED DISCUSSION: The westerly or west-northwesterly flow pattern aloft will continue until about Friday when we will see a transition to a southwesterly flow aloft with a weak trough off the California coast and a ridge over the western United States. This should get the Willamette Valley out of a persistent north wind regime and potentially open up some burn opportunities next week. EXTENDED FORECAST: Wednesday: Cloudy early then clearing slowly. High 84. Light winds early then NW 5-8mph. Wednesday Night: Partly cloudy, 53. Thursday: Mostly sunny. 80. Wind becoming WNW 8-12. Potential burn opportunity. Friday: Mostly sunny, 88. Saturday: Mostly sunny, 88. Sunday: Mostly sunny, 83. Monday: Mostly sunny, 83. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Wed Jul 21 08:55:25 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 21 Jul 2010 10:55:25 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Wed, Jul 21 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT WED JUL 21 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is allowed from 12:00pm to 2:00pm with a 50 acre limit. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: A weak upper-level trough is moving across Washington and Oregon this morning and maintaining the onshore flow into the Willamette Valley. Visible satellite imagery shows marine low clouds blanketing the coast and most of the Willamette Valley with some breaks in the clouds over the coast range. The marine clouds should give way to sunny skies this afternoon. In the wake of the weak trough, a warming northwesterly flow aloft will help temperatures recover into the low 80s. The surface map shows some minor gradient-stacking across western Oregon this morning with 1.2 mb onshore from Newport to Salem and 3.6 mb onshore from Salem to Redmond. Daytime heating may be sufficient to balance out the onshore flow but transport winds will likely remain too northerly for open burning. TODAY?S FORECAST: Morning clouds?becoming sunny and a little warmer this afternoon. After reaching 78 degrees on Tuesday, Salem's high temperature today will be near 83 degrees. The mixing height will climb to near 3000 feet in the early afternoon with a maximum near 3800 feet around 5 p.m. Surface winds will be north at 5-10 mph this morning, becoming NW 5-12 mph this afternoon and evening. Transport winds will be NNW at 7 mph this morning, becoming NNW at 10 mph this afternoon and NW at 10 mph this evening. Relative humidity will drop to 50% by noon and to near 35% by late this afternoon. Salem's sunset tonight: 8:51 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 67 77 83 77 Relative Humidity: 56% 42% 34% 43% Surface Wind Direction: 360 350 340 300 Surface Wind Speed: 5 6 8 10 Transport Wind Direction: 350 350 350 330 Transport Wind Speed: 7 10 10 10 Estimated Mixing Height: 2200 3200 3800 1500 Ventilation Index: 15 32 38 15 EXTENDED DISCUSSION: Another weak upper-level trough will maintain a typical summertime onshore flow pattern Thursday. Depending on the timing of the trough, there could be an open burning opportunity Thursday afternoon, if any fields are ready. A stronger ridge of high pressure is forecast to build over the region Friday and Saturday. Transport winds will turn northerly and perhaps slightly offshore with temperatures climbing to well above normal. The upper-level ridge is forecast to slide east of the region by Sunday with increasing south-southwesterly flow aloft introducing a chance of showers or afternoon thunderstorms to much of the state?mainly south and east of the Willamette Valley. Increasing southwesterly flow aloft is forecast to eventually turn transport winds onshore early next week, which could present an open burning opportunity. However, if the flow aloft becomes too southerly, showers and thunderstorms may also may their way northward into the Willamette Valley. EXTENDED FORECAST: Thursday: Morning clouds with afternoon clearing. Wind: NNW 5-15 mph. 53/80 Friday: Sunny and turning much warmer. Wind: N 5-15 mph. 50/90 Saturday: Sunny and very warm. 56/95 Sunday: Mostly sunny. Very warm. Chance of t-storms near the Cascades. 58/92 Monday: Partly cloudy. Chance of showers or t-storms. 58/86 Tuesday: Partly cloudy. Chance of showers or t-storms. 55/83 Wednesday: Partly cloudy. Chance of showers or t-storms. 54/82 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Wed Jul 21 11:55:19 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 21 Jul 2010 13:55:19 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Wed, Jul 21 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT WED JUL 21 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from now to 7:00pm. Prep burning is allowed from now to 2:00pm with a 50 acre limit. Propane flaming is allowed from now to 5:00pm. WEATHER DISCUSSION: A weak upper-level trough is shifting east of the Cascades at midday with a dry northwesterly flow aloft over western Oregon. That is maintaining the onshore flow into the Willamette Valley. Late-morning visible satellite imagery showed some morning marine low clouds persisting in mainly the extreme northern Willamette Valley and along much of the northern and central coast. The remainder of the state had mostly sunny skies. Midday valley temperatures were mostly in the low to mid 60s. In the wake of the weak trough, a dry northwesterly flow aloft will help to clear the remaining marine clouds from the north valley, with sunny skies helping afternoon temperatures recover into the low 80s. The late-morning surface map showed the morning gradient-stacking already beginning to balance out, with 1.8 mb onshore from Newport to Salem and 3.0 mb onshore from Salem to Redmond. Continued heating this afternoon will likely be sufficient to reverse the stacking of the onshore flow, creating favorable lift for smoke dispersion, but transport winds will likely remain too northerly for open burning. THIS AFTERNOON?S FORECAST: Becoming sunny. A little warmer. Salem's high temperature today will be near 83 degrees. The mixing height will climb to near 3000 feet in the early afternoon with a maximum near 3800 feet around 5 p.m. Surface winds becoming NW 5-12 mph this afternoon and evening. Transport winds NNW at 10 mph this afternoon, backing to NW at 10 mph this evening. Relative humidity will drop to 50% by 1 p.m. and to near 35% by late this afternoon. Salem's sunset tonight: 8:51 pm EXTENDED DISCUSSION: Another weak upper-level trough will maintain the moderately strong onshore flow pattern Thursday. Once again, transport winds are forecast to remain too northerly for open burning opportunities. A stronger ridge of high pressure is forecast to build over the region Friday and Saturday. Transport winds will turn northerly Friday, and perhaps slightly offshore Saturday, with temperatures climbing to well above normal. The upper-level ridge is forecast to slide east of the region by Sunday with increasing south-southwesterly flow aloft introducing a chance of showers or afternoon thunderstorms to much of the state?mainly south and east of the Willamette Valley. Increasing southwesterly flow aloft is forecast to eventually turn transport winds onshore early next week. That could present an open burning opportunity Monday afternoon, if the flow aloft is not too southerly. An increasing southerly component to the upper-level flow is forecast by Tuesday, which will introduce at least a chance of a shower or thundershower into the valley. The flow is forecast to turn more westerly by the middle of next week, with temperatures cooling back to near normal. That transition could also create open burning opportunities. EXTENDED FORECAST: Thursday: Morning clouds with afternoon clearing. Wind: NNW 5-15 mph. 53/80 Friday: Sunny and turning much warmer. Wind: N 5-15 mph. 50/88 Saturday: Sunny and very warm. 56/95 Sunday: Mostly sunny. Very warm. Chance of t-storms near the Cascades. 58/92 Monday: Partly cloudy. Slight chance of showers or t-storms. 58/86 Tuesday: Partly cloudy. Chance of showers or t-storms. 55/85 Wednesday: Partly cloudy. 53/82 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Thu Jul 22 08:55:10 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 22 Jul 2010 10:55:10 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 22 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT THU JUL 22 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is allowed from 12:00pm to 2:00pm with a 50 acre limit. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: Another upper-level trough, cutting across southern British Columbia, will maintain a dry northwesterly flow aloft and moderately strong onshore low-level flow across western Oregon today. Visible satellite imagery shows marine low clouds blanketing most of the coast, but only patchy low clouds have penetrated inland into the northern Willamette Valley. Skies were sunny over the remainder of the state. The surface map shows only very minor gradient-stacking across western Oregon this morning with 1.9 mb onshore from Newport to Salem and 2.5 mb onshore from Salem to Redmond. Like yesterday, daytime heating should balance out the onshore flow, but transport winds will likely remain too northerly for open burning. There has been some minor cooling aloft since Wednesday afternoon, so high temperatures will likely back off a couple of degrees today. Sunny skies will prevail across the valley today with highs near 80. TODAY?S FORECAST: Patchy morning clouds, then sunny but a touch cooler. After reaching 82 degrees on Wednesday, Salem's high temperature today will be near 80 degrees. The mixing height will climb to near 3000 feet in the early afternoon with a maximum near 3800 feet around 5 p.m. Surface and transport winds will be NNW at 4-8 mph this morning, increasing to 8-15 mph this afternoon and early evening. Relative humidity will drop to 50% by noon and to near 38% by late this afternoon. The maximum ventilation index will be near 50 today. Salem's sunset tonight: 8:50 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 68 76 80 72 Relative Humidity: 59% 45% 38% 46% Surface Wind Direction: 350 340 330 310 Surface Wind Speed: 6 7 11 12 Transport Wind Direction: 320 340 340 345 Transport Wind Speed: 4 9 13 14 Estimated Mixing Height: 2200 3500 3800 1500 Ventilation Index: 9 32 49 21 EXTENDED DISCUSSION: A stronger ridge of high pressure is forecast to build over the region Friday and Saturday. Transport winds will turn northerly Friday, and perhaps slightly offshore Saturday, with temperatures climbing to well above normal. The upper-level ridge is forecast to slide east of the region by Sunday with increasing south-southwesterly flow aloft introducing a chance of showers or afternoon thunderstorms to much of the state?mainly south and east of the Willamette Valley. Increasing southwesterly flow aloft is forecast to eventually turn transport winds onshore early next week. That could present open burning opportunities, if the flow aloft does not become too southerly and bring thunderstorms into the valley. The flow is forecast to turn more westerly by the middle of next week, with temperatures cooling back to near normal. That transition could also create open burning opportunities. EXTENDED FORECAST: Friday: Sunny and turning much warmer. Wind: N 5-15 mph. 50/88 Saturday: Sunny and very warm. Wind: NNE 5-15 mph. 56/94 Sunday: Mostly sunny. Very warm. Chance of t-storms near the Cascades. 58/92 Monday: Partly cloudy. Slight chance of showers or t-storms. 58/86 Tuesday: Partly cloudy. Slight chance of showers or t-storms. 55/82 Wednesday: Morning clouds, then mostly sunny. 53/80 Thursday: Patchy morning clouds, then sunny. 52/84 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Thu Jul 22 11:55:28 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 22 Jul 2010 13:55:28 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 22 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT THU JUL 22 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from now to 7:00pm. Prep burning is allowed from now to 2:00pm with a 50 acre limit. Propane flaming is allowed from now to 5:00pm. WEATHER DISCUSSION: A dry cold front is moving across northeastern Oregon, at midday, and initiating moderate to strong onshore flow into northwestern Oregon. Visible satellite imagery shows marine low clouds continuing the cover the extreme northwestern corner of Oregon. Late-morning temperatures were only in the upper 50s along the north coast, with some areas of light drizzle. Meanwhile, patchy morning low clouds had cleared from the northern Willamette Valley, and temperatures had climbed into the upper 60s and low 70s. Skies were sunny over the remainder of the state, except for a few clouds pushing across northeastern Oregon, in association with the dry cold front. The surface map still showed some gradient-stacking across western Oregon late this morning, with 2.6 mb onshore from Newport to Salem and 4.3 mb onshore from Salem to Redmond. Like yesterday, daytime heating should balance out the onshore flow, but transport winds will likely remain too northerly for open burning. The air aloft is cooler than on Wednesday, so even though midday temperatures are slightly warmer than 24 hours ago, a cooling sea breeze should cap afternoon highs short of Wednesday?s readings. TODAY?S FORECAST: Sunny but a touch cooler. After reaching 82 degrees on Wednesday, Salem's high temperature today will be near 80 degrees. The mixing height will climb to near 3000 feet in the early afternoon with a maximum near 3800 feet around 5 p.m. Surface and transport winds will be NNW at 8-15 mph this afternoon and early evening. Relative humidity will drop to near 38% by late this afternoon. The maximum ventilation index will be near 50 today. Salem's sunset tonight: 8:50 pm EXTENDED DISCUSSION: An upper-level ridge of high pressure is forecast to build over the region Friday and Saturday. Transport winds will turn northerly Friday, and perhaps slightly offshore Saturday, with temperatures climbing to well above normal. The ridge is forecast to slide east of the region by Sunday with increasing south-southwesterly flow aloft introducing a chance of showers or afternoon thunderstorms to southern Oregon. These storms should stay south and east of the Willamette Valley. Increasing southwesterly flow aloft is forecast to eventually turn transport winds onshore early next week. That could present open burning opportunities, if the flow aloft does not become too southerly and bring thunderstorms into the valley. The flow is forecast to turn more westerly by the middle of next week, with temperatures cooling back to near normal. That transition could also create open burning opportunities. EXTENDED FORECAST: Friday: Sunny and turning much warmer. Wind: N 5-15 mph. 50/88 Saturday: Sunny and very warm. Wind: NNE 5-15 mph. 56/94 Sunday: Mostly sunny. Very warm. Chance of t-storms near the Cascades. 58/92 Monday: Partly cloudy. Slight chance of showers or t-storms. 58/86 Tuesday: Partly cloudy. Slight chance of showers or t-storms. 55/82 Wednesday: Morning clouds, then mostly sunny. 53/80 Thursday: Patchy morning clouds, then sunny. 52/84 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Fri Jul 23 08:57:29 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 23 Jul 2010 10:57:29 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Fri, Jul 23 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT FRI JUL 23 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 11:00am to 7:00pm. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: An upper-level ridge of high pressure is forecast to build over the region today with transport winds turning northerly and temperatures warming to above normal. Visible satellite imagery shows marine low clouds covering much of the Willamette Valley at mid-morning. However, low clouds were already clearing from all but the extreme north coast, with northerly winds rapidly drying the air mass. Skies were sunny over southwestern Oregon and all areas from the Cascades eastward. The surface map shows the onshore flow is weakening and becoming northerly across western Oregon. There is just 0.7 mb of onshore gradient from Newport to Salem and 2.0 mb onshore gradient from Salem to Redmond. A thermal trough was beginning to build into southwestern Oregon with 6.0 mb of northerly gradient from Astoria to Medford. North winds have already increased to around 15 mph along the southern coast and in the southern Willamette Valley, where gusts to around 25 mph are likely later this afternoon. TODAY?S FORECAST: Morning clouds, then sunny and warmer with brisk north winds. After reaching 81 degrees on Wednesday, Salem's high temperature today will be near 88 degrees. The mixing height will climb to near 3000 feet around noon and top out near 4000 feet around 5 p.m. Surface and transport winds will be northerly at 5-12 mph this morning?increasing to 10-15 mph, with higher gusts, this afternoon. Relative humidity will drop to 50% by noon and bottom out near 27% late this afternoon. The combination of low relative humidity and increasing northerly winds may put the valley into State Fire Marshal conditions later this afternoon. The ventilation index will climb to 60. Salem's sunset tonight: 8:49 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 68 79 87 83 Relative Humidity: 51% 35% 27% 34% Surface Wind Direction: 350 360 360 360 Surface Wind Speed: 10 10 13 9 Transport Wind Direction: 360 010 010 360 Transport Wind Speed: 10 14 15 13 Estimated Mixing Height: 2500 3300 4000 2000 Ventilation Index: 25 46 60 26 EXTENDED DISCUSSION: The upper-level ridge of high pressure is forecast to continue building over the region Saturday. Transport winds will turn slightly offshore, with valley temperatures climbing into the 90s. The ridge is forecast to slide east of the region by Sunday with increasing south-southwesterly flow aloft introducing a chance of showers or afternoon thunderstorms to southern Oregon. These storms should stay south and east of the Willamette Valley. Increasing southwesterly flow aloft is forecast to eventually turn transport winds onshore early next week. That could present open burning opportunities but may also circulate afternoon showers and thunderstorms northward along the Cascades. The flow is forecast to turn more westerly by the middle of next week, with temperatures cooling back to near normal. That transition could also create open burning opportunities. EXTENDED FORECAST: Saturday: Sunny and very warm. Wind: NNE 5-15 mph. 56/94 Sunday: Mostly sunny. Very warm. Chance of t-storms near the Cascades. 58/94 Monday: Partly cloudy. Slight chance of showers or t-storms. 58/86 Tuesday: Partly cloudy. Slight chance of showers or t-storms. 55/82 Wednesday: Morning clouds, then mostly sunny. 53/80 Thursday: Morning clouds, then mostly sunny. 52/78 Friday: Morning clouds, then sunny. 50/83 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Fri Jul 23 09:10:35 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 23 Jul 2010 11:10:35 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Fri, Jul 23 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT FRI JUL 23 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from 11:00am to 7:00pm. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: An upper-level ridge of high pressure is forecast to build over the region today with transport winds turning northerly and temperatures warming to above normal. Visible satellite imagery shows marine low clouds covering much of the Willamette Valley at mid-morning. However, low clouds were already clearing from all but the extreme north coast, with northerly winds rapidly drying the air mass. Skies were sunny over southwestern Oregon and all areas from the Cascades eastward. The surface map shows the onshore flow is weakening and becoming northerly across western Oregon. There is just 0.7 mb of onshore gradient from Newport to Salem and 2.0 mb onshore gradient from Salem to Redmond. A thermal trough was beginning to build into southwestern Oregon with 6.0 mb of northerly gradient from Astoria to Medford. North winds have already increased to around 15 mph along the southern coast and in the southern Willamette Valley, where gusts to around 25 mph are likely later this afternoon. TODAY?S FORECAST (corrected wording): Morning clouds, then sunny and warmer with brisk north winds. After reaching 81 degrees on Thursday, Salem's high temperature today will be near 88 degrees. The mixing height will climb to near 3000 feet around noon and top out near 4000 feet around 5 p.m. Surface and transport winds will be northerly at 5-12 mph this morning?increasing to 10-15 mph, with higher gusts, this afternoon. Relative humidity will drop to 50% by noon and bottom out near 27% late this afternoon. The combination of low relative humidity and increasing northerly winds may put the valley into State Fire Marshal conditions later this afternoon. The ventilation index will climb to 60. Salem's sunset tonight: 8:49 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 68 79 87 83 Relative Humidity: 51% 35% 27% 34% Surface Wind Direction: 350 360 360 360 Surface Wind Speed: 10 10 13 9 Transport Wind Direction: 360 010 010 360 Transport Wind Speed: 10 14 15 13 Estimated Mixing Height: 2500 3300 4000 2000 Ventilation Index: 25 46 60 26 EXTENDED DISCUSSION: The upper-level ridge of high pressure is forecast to continue building over the region Saturday. Transport winds will turn slightly offshore, with valley temperatures climbing into the 90s. The ridge is forecast to slide east of the region by Sunday with increasing south-southwesterly flow aloft introducing a chance of showers or afternoon thunderstorms to southern Oregon. These storms should stay south and east of the Willamette Valley. Increasing southwesterly flow aloft is forecast to eventually turn transport winds onshore early next week. That could present open burning opportunities but may also circulate afternoon showers and thunderstorms northward along the Cascades. The flow is forecast to turn more westerly by the middle of next week, with temperatures cooling back to near normal. That transition could also create open burning opportunities. EXTENDED FORECAST: Saturday: Sunny and very warm. Wind: NNE 5-15 mph. 56/94 Sunday: Mostly sunny. Very warm. Chance of t-storms near the Cascades. 58/94 Monday: Partly cloudy. Slight chance of showers or t-storms. 58/86 Tuesday: Partly cloudy. Slight chance of showers or t-storms. 55/82 Wednesday: Morning clouds, then mostly sunny. 53/80 Thursday: Morning clouds, then mostly sunny. 52/78 Friday: Morning clouds, then sunny. 50/83 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Fri Jul 23 11:57:20 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 23 Jul 2010 13:57:20 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Fri, Jul 23 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT FRI JUL 23 2010 BURN ADVISORY: Recommended burn times for agricultural burning are from now to 7:00pm. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: Late-morning visible satellite imagery showed a couple of pockets of remaining marine low clouds in the northern and central Willamette Valley, with the largest area of clouds centered just north of the Silverton Hills. The remainder of the state had sunny skies, including along the entire coast. The surface map shows only a trickle of onshore flow remaining across northwestern Oregon and offshore flow developing, into a building thermal trough, across southwestern Oregon. There is just 0.1 mb of onshore gradient remaining from Newport to Salem and 1.3 mb onshore gradient from Salem to Redmond. Gradients have turned offshore from Eugene to North Bend and are becoming strong northerly in the Willamette Valley. The south valley was getting northerly winds gusting to nearly 25 mph late this morning, with the south coast seeing gusts to over 30 mph. An upper-level ridge of high pressure is building over the region today with the air aloft rapidly warming and drying. Once the remaining low clouds evaporate, temperatures should warm rapidly in the Willamette Valley. Even though late-morning readings are running as much as 10 degrees colder than 24 hours ago, afternoon highs should end up several degrees warmer than yesterday. The late start to the sunshine, however, may keep northern valley highs in the mid 80s, instead of the previously forecast upper 80s. FORECAST: Becoming sunny and warmer with brisk north winds, especially south. After reaching 81 degrees on Thursday, Salem's high temperature today will be near 86 degrees. The mixing height will climb to near 3000 feet in the early afternoon top out near 3800 feet late this afternoon. Northerly surface and transport winds increase to 10-20 mph this afternoon, with higher gusts possible. Relative humidity will drop to near 27% late this afternoon. The combination of low relative humidity and increasing northerly winds may put the Silverton Hills region into State Fire Marshal conditions by late this afternoon. The ventilation index will climb to around 60 this afternoon. Salem's sunset tonight: 8:49 pm EXTENDED DISCUSSION: The upper-level ridge of high pressure is forecast to continue building over the region Saturday. Transport winds will turn slightly offshore, with valley temperatures climbing into the 90s. The ridge is forecast to slide east of the region by Sunday with increasing south-southwesterly flow aloft introducing a chance of showers or afternoon thunderstorms to southern Oregon. These storms should stay south and east of the Willamette Valley. Increasing southwesterly flow aloft is forecast to eventually turn transport winds onshore early next week. That could present open burning opportunities but may also circulate afternoon showers and thunderstorms northward along the Cascades. Increasing onshore flow will likely cool temperatures back to near normal during the second half of next week. That could also create open burning opportunities. EXTENDED FORECAST: Saturday: Sunny and very warm. Wind: NNE 5-15 mph. 56/94 Sunday: Mostly sunny. Very warm. Chance of t-storms near the Cascades. 58/94 Monday: Partly cloudy. Slight chance of showers or t-storms. 58/86 Tuesday: Partly cloudy. Slight chance of showers or t-storms. 55/82 Wednesday: Morning clouds, then mostly sunny. 53/80 Thursday: Morning clouds, then mostly sunny. 52/78 Friday: Morning clouds, then sunny. 50/83 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Mon Jul 26 08:34:53 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 26 Jul 2010 10:34:53 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Mon, Jul 26 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT MON JUL 26 2010 BURN ADVISORY: Agricultural burning burning is not recommended. Prep burning is allowed from 2:00pm to 5:00pm with a 50 acre limit. Propane flaming is allowed from 2:00pm to 5:00pm. WEATHER DISCUSSION: Upper air charts show a weak trough off the California coast this morning. Upper level flow over Oregon is generally southwesterly. Low level flow is northerly through the valley and likely will stay northerly through most of the day. There is a slight possibility of a wind shift late in the afternoon. Any wind shift is dependent on pressure gradients developing in a favorable manner. Pressure gradients as of 8am included: Newport to Salem, 2.5 mb onshore; Salem to Redmond, 1.1 mb onshore for a total onshore gradient of 3.6mb. This is a favorable pattern. However if thunderstorms again develop this afternoon east of the Cascades in the southwesterly flow aloft (which is likely) pressures will increase east side and the gradient pattern may become unfavorable. Close monitoring of weather conditions today will be necessary to determine if any burning is possible. Afternoon pibals will tell the story. For the mid Willamette Valley today expect abundant sunshine. Salem's high temperature will be near 90. Relative humidity drops to 50% by 10am. Minimum relative humidity 26%. Expect light northerly surface winds with a shift to northwesterly late. Sunset tonight: 8:40 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 76 86 90 81 Relative Humidity: 46% 32% 26% 37% Surface Wind Direction: 360 350 330 280 Surface Wind Speed: 4 6 7 7 Transport Wind Direction: 360 360 360 300 Transport Wind Speed: 5 5 5 8 Estimated Mixing Height: 2000 4300 4700 1000 Ventilation Index: 10 22 24 8 EXTENDED DISCUSSION: The trough off the coast will help reinforce the marine layer the next couple of days. More marine air will make it into the valley for slowly decreasing temperatures through mid week. Thunderstorms development east of the Cascades is likely throughout the week which will complicate the pressure gradient situation across the Cascades. Again, careful monitoring will be required to detect burn opportunities. EXTENDED FORECAST: Tuesday: Sunny, with a high near 85. Winds light becoming W 5-8. Potential burn opportunity. Wednesday: Sunny, 83. Wind W6. Potential burn opportunity. Thursday: Partly sunny, 82. Friday: Partly sunny, 81. Saturday: Mostly sunny, 82. Sunday: Mostly sunny, 82. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Mon Jul 26 11:47:13 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 26 Jul 2010 13:47:13 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Mon, Jul 26 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00PM PDT MON JUL 26 2010 BURN ADVISORY: Agricultural burning burning is not recommended. Prep burning is allowed from 2:00pm to 5:00pm with a 50 acre limit. Propane flaming is allowed from 2:00pm to 5:00pm. WEATHER DISCUSSION: Upper air charts continue to show a weak trough off the California coast this morning. Upper level flow over Oregon is generally southwesterly. Low level flow is northerly through the valley and likely will stay northerly through most of the day. There is a slight possibility of a wind shift late in the afternoon. Any wind shift is dependent on pressure gradients developing in a favorable manner. Pressures have been fairly steady throughout the morning along the coast, dropping in the Willamette Valley and dropping a little more rapidly in central Oregon. Gradient stacking to the east has not been an issue so far today and likely will not be. If thunderstorms again develop this afternoon east of the Cascades in the southwesterly flow aloft (some lightning has already been reported east of Bend) pressures will increase east side and we could lose the easterly gradient across the Cascades. Close monitoring of weather conditions today will be necessary to determine if any burning is possible. For the mid-Willamette Valley this afternoon expect abundant sunshine. Salem's high temperature will be near 90. Minimum relative humidity drops to 26%. Expect light northerly surface winds with a shift to northwesterly late. Sunset tonight: 8:40 pm THREE-HOURLY DATA: Temperature: 85 90 78 Relative Humidity: 32% 27% 40% Surface Wind Direction: 350 340 280 Surface Wind Speed: 6 7 7 Transport Wind Direction: 360 360 300 Transport Wind Speed: 5 5 8 Estimated Mixing Height: 4300 4700 1000 Ventilation Index: 22 24 8 EXTENDED DISCUSSION: The trough off the coast will help reinforce the marine layer the next couple of days. More marine air will make it into the valley for slowly decreasing temperatures through mid week. Thunderstorms development east of the Cascades is likely throughout the week which will complicate the pressure gradient situation across the Cascades. Again, careful monitoring will be required to detect burn opportunities. EXTENDED FORECAST: Tuesday: Sunny, with a high near 85. Winds light becoming W 5-8. Potential burn opportunity. Wednesday: Sunny, 83. Wind W6. Potential burn opportunity. Thursday: Partly sunny, 82. Friday: Partly sunny, 81. Saturday: Mostly sunny, 82. Sunday: Mostly sunny, 82. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Tue Jul 27 08:55:00 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 27 Jul 2010 10:55:00 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 27 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT TUE JUL 27 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is allowed from 2:00 p.m. until 5:00 p.m. WEATHER DISCUSSION: A weak upper-level trough, just offshore, will bring light south-southwesterly flow aloft to western Oregon today. Weak onshore flow at the surface brought marine clouds into the coastal range gaps this morning, with some low clouds making up the Columbia River into the extreme north valley. Otherwise skies were sunny over the Willamette Valley at mid-morning, but temperatures were generally about 5 degrees cooler than 24 hours ago. The surface map shows weak but even onshore flow across western Oregon, so gradient-stacking should not be an issue today. Weather conditions and transport winds will need to be monitored today for the slight possibility of open burning later this afternoon. A strong southerly component to the upper-level winds will act to suppress mixing heights. In addition, onshore flow may be too weak to permit open burning. Afternoon thunderstorm development is likely again over central Oregon, which would also act to inhibit smoke evacuation over the Cascades. TODAY?S FORECAST: Sunny but not quite as warm. After reaching 91 degrees on Monday, Salem's high temperature today will be near 88 degrees. The mixing height will not climb to 3000 feet until around 2 p.m. and will likely top out just below 4000 feet late this afternoon. Surface and transport winds will be NW 3-8 this morning and NW 5-10 this aftenroon. Relative humidity will drop to 50% by noon and bottom out near 30% late this afternoon. The ventilation index will only climb to about 21. Salem's sunset tonight: 8:44 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 71 81 86 77 Relative Humidity: 51% 37% 30% 41% Surface Wind Direction: 330 330 330 280 Surface Wind Speed: 3 6 7 7 Transport Wind Direction: 300 330 330 300 Transport Wind Speed: 4 5 6 7 Estimated Mixing Height: 2000 3000 3500 1500 Ventilation Index: 8 15 21 10 EXTENDED DISCUSSION: A weak upper-level trough will slightly increase the southwesterly flow aloft over Oregon Wednesday and Thursday. That will further increase the onshore flow at the surface and cool high temperatures a couple of more degrees each day. The onshore flow may still be too weak to allow for open burning but will need to be monitored closely. The upper-level trough is forecast to finally move onshore Friday, which may generate enough onshore flow t bring morning marine clouds into the Willamette Valley. That will cool temperatures back to near normal and could also create an open burning opportunity. The upper-level trough is forecast to move across Oregon over the weekend with the flow aloft turning northwesterly by Sunday. That will continue to bring onshore flow and near-normal temperatures to the Willamette Valley. Another weak upper-level trough may move into the region early next week, with little change in the overall weather conditions. EXTENDED FORECAST: Wednesday: Mostly sunny. A touch cooler. Wind: NW 5-10 mph. 52/85 Thursday: Mostly sunny. A little cooler. Wind: NW 5-10 mph. 52/83 Friday: Morning clouds, then sunny. Wind: NW 5-15 mph. 50/82 Saturday: Morning clouds, then sunny. 50/80 Sunday: Morning clouds, then sunny. 50/83 Monday: Morning clouds, then sunny. 52/83 Tuesday: Morning clouds, then sunny. 52/82 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Tue Jul 27 11:55:06 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 27 Jul 2010 13:55:06 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 27 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT TUE JUL 27 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is allowed from 2:00 p.m. until 5:00 p.m. WEATHER DISCUSSION: A slight increase in the onshore flow overnight allowed patchy marine low clouds to penetrate inland, into the extreme northern and southern ends of the Willamette Valley, by early this morning. Late-morning visible satellite imagery showed the marine clouds had cleared from the interior valleys and were backing out of the coastal mountain gaps. However, most of the coast was still cloudy. Temperatures were running several degrees cooler than 24 hours ago and ranged from the mid 50s along the coast to near 70 in the Willamette Valley. Winds in the valley were light and variable. The surface map shows weak but even onshore flow across western Oregon, into a thermal trough stretching from east-central Washington, through central Oregon, to southwestern Oregon. Gradient-stacking is not an issue today for open burning. However, the onshore flow may be too weak to evacuate smoke over the Cascades and will need to be monitored this afternoon. A weak upper-level trough is approaching the coastline and backing the winds aloft from southwesterly to more southerly. That will act to limit the amount of onshore flow today and could also suppress mixing heights. Afternoon thunderstorm development is likely again over central Oregon, which would raise pressures east of the Cascades and also act to reduce the onshore flow across western Oregon. TODAY?S FORECAST: Sunny but not quite as warm. Salem's high temperature today will be near 87 degrees. The mixing height will not climb to 3000 feet until around 2 p.m. and will likely top out near 3800 feet late this afternoon. Surface and transport winds will be NW at just 5-10 mph this afternoon. Relative humidity will drop to near 30% late this afternoon. The ventilation index will only climb to about 21. Salem's sunset tonight: 8:44 pm EXTENDED DISCUSSION: A weak upper-level trough will slightly increase the southwesterly flow aloft over Oregon Wednesday and Thursday. That will further increase the onshore flow at the surface and cool high temperatures a couple of more degrees each day. The onshore flow may still be too weak to allow for open burning but will need to be monitored closely. The upper-level trough is forecast to finally move onshore Friday, which may generate enough onshore flow t bring morning marine clouds into the Willamette Valley. That will cool temperatures back to near normal and could also create an open burning opportunity. The upper-level trough is forecast to move across Oregon over the weekend with the flow aloft turning northwesterly by Sunday. That will continue to bring onshore flow and near-normal temperatures to the Willamette Valley. Another weak upper-level trough may move into the region early next week, with little change in the overall weather conditions. EXTENDED FORECAST: Wednesday: Mostly sunny. Wind: NW 5-10 mph. 52/85 Thursday: Mostly sunny. Wind: NW 5-10 mph. 52/84 Friday: Morning clouds, then sunny. Wind: NW 5-15 mph. 50/82 Saturday: Morning clouds, then sunny. 50/80 Sunday: Morning clouds, then sunny. 50/83 Monday: Morning clouds, then sunny. 52/83 Tuesday: Morning clouds, then sunny. 52/82 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Tue Jul 27 12:20:44 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 27 Jul 2010 12:20:44 -0700 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, July 27, 2010 Message-ID: <8CD18C5BD70D6F4BB2B636295905299C8A2FEF06@WPODFEXCL01.ODF.STATE.OR.US> SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT TUE JUL 27 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is allowed from 2:00 p.m. until 5:00 p.m. WEATHER DISCUSSION: A slight increase in the onshore flow overnight allowed patchy marine low clouds to penetrate inland, into the extreme northern and southern ends of the Willamette Valley, by early this morning. Late-morning visible satellite imagery showed the marine clouds had cleared from the interior valleys and were backing out of the coastal mountain gaps. However, most of the coast was still cloudy. Temperatures were running several degrees cooler than 24 hours ago and ranged from the mid 50s along the coast to near 70 in the Willamette Valley. Winds in the valley were light and variable. The surface map shows weak but even onshore flow across western Oregon, into a thermal trough stretching from east-central Washington, through central Oregon, to southwestern Oregon. Gradient-stacking is not an issue today for open burning. However, the onshore flow may be too weak to evacuate smoke over the Cascades and will need to be monitored this afternoon. A weak upper-level trough is approaching the coastline and backing the winds aloft from southwesterly to more southerly. That will act to limit the amount of onshore flow today and could also suppress mixing heights. Afternoon thunderstorm development is likely again over central Oregon, which would raise pressures east of the Cascades and also act to reduce the onshore flow across western Oregon. TODAY'S FORECAST: Sunny but not quite as warm. Salem's high temperature today will be near 87 degrees. The mixing height will not climb to 3000 feet until around 2 p.m. and will likely top out near 3800 feet late this afternoon. Surface and transport winds will be NW at just 5-10 mph this afternoon. Relative humidity will drop to near 30% late this afternoon. The ventilation index will only climb to about 21. Salem's sunset tonight: 8:44 pm EXTENDED DISCUSSION: A weak upper-level trough will slightly increase the southwesterly flow aloft over Oregon Wednesday and Thursday. That will further increase the onshore flow at the surface and cool high temperatures a couple of more degrees each day. The onshore flow may still be too weak to allow for open burning but will need to be monitored closely. The upper-level trough is forecast to finally move onshore Friday, which may generate enough onshore flow t bring morning marine clouds into the Willamette Valley. That will cool temperatures back to near normal and could also create an open burning opportunity. The upper-level trough is forecast to move across Oregon over the weekend with the flow aloft turning northwesterly by Sunday. That will continue to bring onshore flow and near-normal temperatures to the Willamette Valley. Another weak upper-level trough may move into the region early next week, with little change in the overall weather conditions. EXTENDED FORECAST: Wednesday: Mostly sunny. Wind: NW 5-10 mph. 52/85 Thursday: Mostly sunny. Wind: NW 5-10 mph. 52/84 Friday: Morning clouds, then sunny. Wind: NW 5-15 mph. 50/82 Saturday: Morning clouds, then sunny. 50/80 Sunday: Morning clouds, then sunny. 50/83 Monday: Morning clouds, then sunny. 52/83 Tuesday: Morning clouds, then sunny. 52/82 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Wed Jul 28 08:55:54 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 28 Jul 2010 10:55:54 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Wed, Jul 28 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT WED JUL 28 2010 BURN ADVISORY: Agricultural burning burning is not recommended. Prep burning is not allowed. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: Upper level trough remains off the coast today ever so slowly moving eastward. Thundershowers will again build over the Cascades as the upper level flow remains mostly southerly. Equipment problems prevented receiving an upper air sounding out of Salem so we're operating a little in the blind. However surface pattern shows variable to northerly wind flow this morning. Low clouds have again banked up against the Coast Range with some clouds moving through the Columbia River corridor and down the north valley. Above mid level clouds are from some of the thunderstorm blowoff to the east. Expect low clouds to dissipate with mid clouds to remain somewhat throughout the day. Thus temperatures will be a little cooler than yesterday with the high temperature today in the mid 80s. With slightly cooler temperatures and some cloud cover, humidities will be somewhat higher. Humidity will drop below 50 percent by noon with a minimum around 37 percent around 5 p.m. Wind flow will be light through the morning, gradually showing a tendency toward northwesterly this afternoon as the inland temperatures warm up. With continuing thunderstorms over the Cascades and not a big increase in onshore pressure gradients, burning conditions will be somewhat marginal and will need pibals to determine the strength of onshore flow later today. Sunset tonight: 8:38 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 71 80 84 76 Relative Humidity: 53% 41% 37% 46% Surface Wind Direction: 350 310 290 270 Surface Wind Speed: 2 5 8 7 Transport Wind Direction: 360 340 300 290 Transport Wind Speed: 2 6 8 11 Estimated Mixing Height: 2000 3000 4000 1000 Ventilation Index: 4 18 32 11 EXTENDED DISCUSSION: Upper level low will gradually move eastward through the remainder of the week and weekend. Thunderstorm threat will continue over the Cascades through Friday but as the low approaches, thunderstorms should move eastward and allow surface pressure gradients to increase, giving an improved chance for open burning on Friday. Eventually the trough moves to the east over the weekend and gives way to northwesterly flow aloft early next week. Temperatures will continue to cool toward the weekend with marine low clouds likely moving in over the weekend. EXTENDED FORECAST: Thursday: Mostly sunny, with a high near 82. Calm wind becoming north between 4 and 7 mph. Thursday Night: Partly cloudy, with a low around 51. North wind around 6 mph becoming calm. Friday: Mostly sunny, with a high near 82. Calm wind becoming north northwest around 6 mph. Friday Night: Mostly cloudy, with a low around 50. Saturday: Mostly sunny, with a high near 76. Saturday Night: Partly cloudy, with a low around 52. Sunday: Mostly sunny, with a high near 78. Sunday Night: Mostly cloudy, with a low around 52. Monday: Mostly sunny, with a high near 82. Monday Night: Partly cloudy, with a low around 52. Tuesday: Mostly sunny, with a high near 84. ? Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Wed Jul 28 11:55:33 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 28 Jul 2010 13:55:33 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Wed, Jul 28 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT WED JUL 28 2010 BURN ADVISORY: Agricultural burning burning is not recommended. Prep burning is not allowed. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: Upper level trough remains off the coast today ever so slowly moving eastward. Thundershowers are moving through central Oregon in the last few hours. This is keeping pressure gradients flat between Salem and Redmond with hazy conditions east of Salem. However models show more westerly flow developing during the afternoon. Will need pibals to confirm this. Low clouds have burned off in the valley with middle and higher clouds remaining. Expect middle and high clouds to remain somewhat throughout the day. Thus temperatures will be a little cooler than yesterday with the high temperatures today in the low to mid 80s. With slightly cooler temperatures and some cloud cover, humidities will be somewhat higher. Humidity will drop below 50 percent by 1 to 2 p.m. with a minimum around 42 percent around 5 p.m. Wind flow will be light through the early afternoon, gradually showing a tendency toward west to northwest later this afternoon as the inland temperatures warm up. With thunderstorms likely developing over the Cascades and not a big increase in onshore pressure gradients, burning conditions are still questionable for later this afternoon. Sunset tonight: 8:38 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 78 83 75 Relative Humidity: 48% 42% 46% Surface Wind Direction: 310 290 270 Surface Wind Speed: 6 8 8 Transport Wind Direction: 300 300 290 Transport Wind Speed: 5 8 11 Estimated Mixing Height: 3000 4000 1000 Ventilation Index: 18 32 11 EXTENDED DISCUSSION: Upper level low will gradually move eastward through the remainder of the week and weekend. Thunderstorm threat will continue over the Cascades through Friday but as the low approaches, thunderstorms should move eastward and allow surface pressure gradients to increase, giving an improved chance for open burning on Friday. Eventually the trough moves to the east over the weekend and gives way to northwesterly flow aloft early next week. Temperatures will continue to cool toward the weekend with marine low clouds likely moving in over the weekend. EXTENDED FORECAST: Thursday: Mostly sunny, with a high near 82. Calm wind becoming north between 4 and 7 mph. Thursday Night: Partly cloudy, with a low around 51. North wind around 6 mph becoming calm. Friday: Mostly sunny, with a high near 82. Calm wind becoming north northwest around 6 mph. Friday Night: Mostly cloudy, with a low around 50. Saturday: Mostly sunny, with a high near 76. Saturday Night: Partly cloudy, with a low around 52. Sunday: Mostly sunny, with a high near 78. Sunday Night: Mostly cloudy, with a low around 52. Monday: Mostly sunny, with a high near 82. Monday Night: Partly cloudy, with a low around 52. Tuesday: Mostly sunny, with a high near 84. ? Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Tue Jul 27 12:00:36 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 27 Jul 2010 14:00:36 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Tue, Jul 27 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT TUE JUL 27 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is allowed from 2:00 p.m. until 5:00 p.m. WEATHER DISCUSSION: A slight increase in the onshore flow overnight allowed patchy marine low clouds to penetrate inland, into the extreme northern and southern ends of the Willamette Valley, by early this morning. Late-morning visible satellite imagery showed the marine clouds had cleared from the interior valleys and were backing out of the coastal mountain gaps. However, most of the coast was still cloudy. Temperatures were running several degrees cooler than 24 hours ago and ranged from the mid 50s along the coast to near 70 in the Willamette Valley. Winds in the valley were light and variable. The surface map shows weak but even onshore flow across western Oregon, into a thermal trough stretching from east-central Washington, through central Oregon, to southwestern Oregon. Gradient-stacking is not an issue today for open burning. However, the onshore flow may be too weak to evacuate smoke over the Cascades and will need to be monitored this afternoon. A weak upper-level trough is approaching the coastline and backing the winds aloft from southwesterly to more southerly. That will act to limit the amount of onshore flow today and could also suppress mixing heights. Afternoon thunderstorm development is likely again over central Oregon, which would raise pressures east of the Cascades and also act to reduce the onshore flow across western Oregon. TODAY?S FORECAST: Sunny but not quite as warm. Salem's high temperature today will be near 87 degrees. The mixing height will not climb to 3000 feet until around 2 p.m. and will likely top out near 3800 feet late this afternoon. Surface and transport winds will be NW at just 5-10 mph this afternoon. Relative humidity will drop to near 30% late this afternoon. The ventilation index will only climb to about 21. Salem's sunset tonight: 8:44 pm EXTENDED DISCUSSION: A weak upper-level trough will slightly increase the southwesterly flow aloft over Oregon Wednesday and Thursday. That will further increase the onshore flow at the surface and cool high temperatures a couple of more degrees each day. The onshore flow may still be too weak to allow for open burning but will need to be monitored closely. The upper-level trough is forecast to finally move onshore Friday, which may generate enough onshore flow t bring morning marine clouds into the Willamette Valley. That will cool temperatures back to near normal and could also create an open burning opportunity. The upper-level trough is forecast to move across Oregon over the weekend with the flow aloft turning northwesterly by Sunday. That will continue to bring onshore flow and near-normal temperatures to the Willamette Valley. Another weak upper-level trough may move into the region early next week, with little change in the overall weather conditions. EXTENDED FORECAST: Wednesday: Mostly sunny. Wind: NW 5-10 mph. 52/85 Thursday: Mostly sunny. Wind: NW 5-10 mph. 52/84 Friday: Morning clouds, then sunny. Wind: NW 5-15 mph. 50/82 Saturday: Morning clouds, then sunny. 50/80 Sunday: Morning clouds, then sunny. 50/83 Monday: Morning clouds, then sunny. 52/83 Tuesday: Morning clouds, then sunny. 52/82 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist From willamette-fcst at listsmart.osl.state.or.us Thu Jul 29 08:33:11 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 29 Jul 2010 10:33:11 -0500 Subject: [willamette-fcst] Silverton Hills Forecast - Thu, Jul 29 2010 Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT THU JUL 29 2010 BURN ADVISORY: Agricultural burning burning is not recommended. Prep burning is allowed from 2:00pm to 5:00pm with a 50 acre limit. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: Once again today upper air charts show a weak trough off the coast of North America and an upper level high centered over the four-corners area of the southwest United States. This is giving a southwesterly flow aloft over western Oregon. At lower levels, however, northerly winds are the rule. The morning Salem sounding showed very stable conditions to about 6000 feet. Several weak inversions were visible in the temperature trace. Sunshine today should push mid-valley temperatures into the low 80's and the warmer surface temperatures will push mixing heights to around 4000 feet this afternoon, but the stable layer above will cap plume rise. The limitation on open field burning today will be wind direction. Models are indicating a continuing northerly wind for today in the Willamette Valley. The Newport to Redmond onshore gradient as of 8:00am this morning was 3.1mb while Portland was showing a 3.5mb northerly gradient. Trajectory forecasts from the Air Resources Laboratory show any smoke released from mid-Marion County headed southward toware mid-Lane County. Models, of course, have difficulty timing the onset of a sea-breeze which could provide a burning opportunity. One wild-card in the weather today is thunderstorm development over and east of the Cascades. Careful monitoring of the pressure pattern and pibal releases will again be necessary to discern any potential burn window. Expect full sunshine today. Temperatures should be up a few degrees from yesterday. Salem's high temperature today will be near 83. Relative humidity drops to 50% by 12pm. Minimum relative humidity 34%. Sunset tonight: 8:37 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 68 77 83 75 Relative Humidity: 55% 42% 34% 46% Surface Wind Direction: 360 350 340 290 Surface Wind Speed: 4 6 7 7 Transport Wind Direction: 360 360 360 330 Transport Wind Speed: 5 6 6 7 Estimated Mixing Height: 2100 3100 3800 1000 Ventilation Index: 10 19 23 7 EXTENDED DISCUSSION: The upper level trough off the coast will kick out several minor disturbances before finally moving eastward over the weekend. This will leave the region under a dry, northerly flow aloft. Low level gradients will be onshore and there may be some burn opportunities early next week. EXTENDED FORECAST: Friday: Mostly sunny, 82. Winds becoming WNW 5-8. Possible burn opportunity. Saturday: Mostly sunny, with a high near 75. Wind WSW-5-10 . Sunday: Mostly sunny, with a high near 77. Monday: Mostly sunny, with a high near 84. Tuesday: Mostly sunny, 87. Wednesday: Mostly sunny, 83. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. From willamette-fcst at listsmart.osl.state.or.us Fri Jul 30 09:00:08 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 30 Jul 2010 09:00:08 -0700 Subject: [willamette-fcst] Silverton Hills Forecast - FRI, JULY 30 2010 Message-ID: <8CD18C5BD70D6F4BB2B636295905299C8A2FF449@WPODFEXCL01.ODF.STATE.OR.US> SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT FRI JUL 30 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is allowed from 2:00 p.m. until 5:00 p.m. WEATHER DISCUSSION: A weak upper-level trough, just offshore, will bring south-southwesterly flow aloft to Oregon again today. Weak onshore flow brought marine low clouds onto the coastline again this morning, with some penetration into the extreme northern Willamette Valley. Otherwise, skies were mostly sunny again this morning with light winds. The Salem sounding this morning was similar to yesterday morning with a very stable atmosphere extending from the surface to about 8000 feet. That will retard the daily rise in mixing heights again today. The offshore trough is forecast to begin moving onshore sounding from Salem surface map shows weak but even onshore later this afternoon. That should increase the onshore flow and may turn transport winds enough northwesterly to provide an open burning opportunity. Pressure gradients are forecast to be favorable for maintaining lift. However, afternoon thunderstorm development is possible along the Cascades and will need to be closely watched. TODAY'S FORECAST: Mostly sunny and warm. After reaching 85 degrees on Thursday, Salem's high temperature today will be near 84 degrees. The mixing height will not climb to 3000 feet until around 2 p.m. but will likely jump to nearly 4500 feet, late this afternoon, before a cooling sea breeze quickly drops it to around 1000 feet just before sunset. Surface and transport winds will be NNW 3-7 this morning and back to NW 6-10 this afternoon. Relative humidity will drop to 50% by noon and to near 32% by late this afternoon. The ventilation index will be low through midday, before jumping to about 36 late this afternoon. Silverton area sunset tonight: 8:35 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 69 78 84 73 Relative Humidity: 52% 41% 32% 48% Surface Wind Direction: 350 320 310 280 Surface Wind Speed: 4 5 7 7 Transport Wind Direction: 340 330 320 300 Transport Wind Speed: 5 6 8 9 Estimated Mixing Height: 1800 3000 4500 1000 Ventilation Index: 9 18 36 9 EXTENDED DISCUSSION: The upper-level trough is forecast to move across Oregon over the weekend with the flow aloft turning northwesterly by Sunday. That will continue to bring onshore flow and near-normal temperatures to the Willamette Valley. Another weak upper-level trough may move into the region early next week, with little change in the overall weather conditions. Western flow aloft and onshore low-level flow may provide multiple burning opportunities next week. EXTENDED FORECAST: Saturday: Cloudy through mid morning, then gradual clearing. High near 73. Saturday Night: Partly cloudy, with a low around 50. Sunday: Mostly sunny, with a high near 80. Monday: Mostly sunny, with a high near 81. Tuesday: Mostly sunny, with a high near 80. Wednesday: Mostly sunny, with a high near 83. Thursday: Mostly sunny, with a high near 82. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 30 09:18:46 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 30 Jul 2010 09:18:46 -0700 Subject: [willamette-fcst] Corrected Silverton Hills Forecast - FRI, JULY 30 2010 Message-ID: <8CD18C5BD70D6F4BB2B636295905299C8A2FF456@WPODFEXCL01.ODF.STATE.OR.US> SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 9:00 AM PDT FRI JUL 30 2010 ...Corrected Wording in Weather Discussion... BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is allowed from 2:00 p.m. until 5:00 p.m. WEATHER DISCUSSION: A weak upper-level trough, just offshore, will bring south-southwesterly flow aloft to Oregon again today. Weak onshore flow brought marine low clouds onto the coastline again this morning, with some penetration into the extreme northern Willamette Valley. Otherwise, skies were mostly sunny again this morning with light winds. The Salem sounding this morning was similar to yesterday morning with a very stable atmosphere extending from the surface to about 8000 feet. That will retard the daily rise in mixing heights again today. The upper-level trough is forecast to begin moving onshore this afternoon, which will cool the air aloft and increase the onshore flow. Transport winds may back enough to the northwest to provide an open burning opportunity. Pressure gradients are forecast to be favorable for keeping smoke elevated, but afternoon thunderstorm development is possible along the Cascades and will need to be closely watched. TODAY'S FORECAST: Mostly sunny and warm. After reaching 85 degrees on Thursday, Salem's high temperature today will be near 84 degrees. The mixing height will not climb to 3000 feet until around 2 p.m. but will likely jump to nearly 4500 feet, late this afternoon, before a cooling sea breeze quickly drops it to around 1000 feet just before sunset. Surface and transport winds will be NNW 3-7 this morning and back to NW 6-10 this afternoon. Relative humidity will drop to 50% by noon and to near 32% by late this afternoon. The ventilation index will be low through midday, before jumping to about 36 late this afternoon. Silverton area sunset tonight: 8:35 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 69 78 84 73 Relative Humidity: 52% 41% 32% 48% Surface Wind Direction: 350 320 310 280 Surface Wind Speed: 4 5 7 7 Transport Wind Direction: 340 330 320 300 Transport Wind Speed: 5 6 8 9 Estimated Mixing Height: 1800 3000 4500 1000 Ventilation Index: 9 18 36 9 EXTENDED DISCUSSION: The upper-level trough is forecast to move across Oregon over the weekend with the flow aloft turning northwesterly by Sunday. That will continue to bring onshore flow and near-normal temperatures to the Willamette Valley. Another weak upper-level trough may move into the region early next week, with little change in the overall weather conditions. Western flow aloft and onshore low-level flow may provide multiple burning opportunities next week. EXTENDED FORECAST: Saturday: Cloudy through mid morning, then gradual clearing. High near 73. Saturday Night: Partly cloudy, with a low around 50. Sunday: Mostly sunny, with a high near 80. Monday: Mostly sunny, with a high near 81. Tuesday: Mostly sunny, with a high near 80. Wednesday: Mostly sunny, with a high near 83. Thursday: Mostly sunny, with a high near 82. Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 30 11:58:08 2010 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 30 Jul 2010 11:58:08 -0700 Subject: [willamette-fcst] Silverton Hills Forecast - FRI, JULY 30 2010 Message-ID: <8CD18C5BD70D6F4BB2B636295905299C8A2FF4CB@WPODFEXCL01.ODF.STATE.OR.US> SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 12:00 PM PDT FRI JUL 30 2010 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is allowed from 2:00 p.m. until 5:00 p.m. WEATHER DISCUSSION: Midday satellite imagery shows low clouds continuing to blanket the northern and central coast but beginning to break up in the extreme northern Willamette Valley. The central and southern valley avoided marine clouds this morning. Temperatures are running within a degree or two of 24 hours ago, so the high temperature forecast of 84 degrees looks on track. The late-morning surface analysis showed the thermal trough had shifted just east of Redmond with weak onshore flow across western Oregon. There was some mild gradient-stacking, with 2.7 mb from Newport to Salem and 4.2 mb from Salem to Redmond, but daytime heating should reverse that by 3 p.m. The significant weather feature today is an upper-level trough that is sluggishly advancing closer to the coastline. The air aloft is slowly cooling, which should provide higher mixing heights today compared with the past couple of afternoons. It is still uncertain if this system will progress far enough eastward to create an open burning opportunity this afternoon, but at least marginal burning conditions appear likely to develop. Transport winds will need to be closely monitored, for a forecast shift to northwesterly, this afternoon. Possible thunderstorm development, over the Cascades, will also need to be closely watched, because that could adversely affect the pressure gradient-stacking and inhibit smoke evacuation. TODAY'S FORECAST: Mostly sunny and warm. Salem's high temperature today will be near 84 degrees. The mixing height will not climb to 3000 feet until around 2 p.m. but may rapidly lift to near 4500 feet. Look for a cooling sea breeze to quickly drop to mixing height to around 1000 feet just before sunset. Light surface and transport winds should increase and turn northwesterly this afternoon. Relative humidity will drop to near 32% by late this afternoon. The ventilation index should climb to about 36 late this afternoon. Silverton area sunset tonight: 8:35 pm EXTENDED DISCUSSION: The upper-level trough is forecast to move across Oregon over the weekend with the flow aloft turning northwesterly by Sunday. That will bring a significant surge of marine air into the Willamette Valley with high temperatures cooling to below normal. Another weak upper-level trough may move into the region early next week, with continued onshore flow only allowing temperatures to warm to near normal. This weather pattern may provide multiple burning opportunities during the upcoming week. EXTENDED FORECAST: Saturday: Morning clouds, then mostly sunny but cooler. 52/75 Sunday: Morning clouds, then mostly sunny. 51/79 Monday: Morning clouds, then mostly sunny. 51/80 Tuesday: Mostly sunny. 52/84 Wednesday: Mostly sunny. 52/83 Thursday: Morning clouds, then mostly sunny. 52/82 Friday: Morning clouds, then mostly sunny. 52/81 Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer times the transport wind speed divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture and the Oregon Department of Forestry. For information contact ODA at 503-986-4701. Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: