From willamette-fcst at listsmart.osl.state.or.us Wed Jul 6 08:53:46 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 6 Jul 2011 08:53:46 -0700 Subject: [willamette-fcst] Willamette-fcst Silverton Hills Forecast Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT WED JUL 6, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 10:00 a.m. to 7:00 p.m. WEATHER DISCUSSION: A ridge of high pressure will remain over the Pacific Northwest today with light southwesterly flow aloft over Oregon. Mid-morning visible satellite imagery showed low clouds banked up along much of the coastal strip with minimal inland penetration. Skies were sunny across the remainder of the state. Surface pressure gradients will remain strongly northerly today, as a surface thermal trough tries to build northward into southwestern Oregon. TODAY'S FORECAST: Sunny and very warm. Once again, today's high temperature will near 88 degrees. The mixing height should climb to around 3000 feet between 1 p.m. and 2 p.m. and top out just over 4000 feet around 5 p.m. Surface winds will be generally northerly at around 10 mph, and transport winds will also be mostly northerly at 15-20 mph. Surface and transport winds will turn northwesterly in the evening. Relative humidity levels will drop to around 45% by 11 a.m. and to near 30% by 5 p.m. Salem sunset tonight: 9:01pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 76 83 88 80 Relative Humidity: 45% 36% 31% 43% Surface Wind Direction: 360 355 350 320 Surface Wind Speed: 8 10 11 10 Transport Wind Direction: 010 358 355 330 Transport Wind Speed: 15 17 19 17 Estimated Mixing Height: 2200 3500 4200 2500 Ventilation Index: 33 60 80 42 EXTENDED DISCUSSION: An upper-level trough is forecast to approach the coastline Thursday and force the surface thermal trough into eastern Oregon. That will induce a significant "marine push" into western Oregon during the day. Look for increasing clouds with a slight chance of a light shower in the afternoon. Temperatures will cool back to near or slightly below normal. The upper-level trough is forecast to move across Washington and northern Oregon on Friday. Strong onshore flow will bring considerable marine clouds inland with afternoon clearing. Temperatures will cool to 5-10 degrees below normal with a chance of morning drizzle or light showers. The pattern of southwesterly winds aloft, with onshore low-level flow, is forecast to continue into at least early next week. Generally dry weather with seasonal temperatures can be expected. 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 6 11:41:45 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 6 Jul 2011 11:41:45 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 28160 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 7 08:56:08 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 7 Jul 2011 08:56:08 -0700 Subject: [willamette-fcst] Silverton Hills Forecast Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT THU JUL 7, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 10:00 a.m. to 7:00 p.m. WEATHER DISCUSSION: A "marine push" underway this morning, with pressure gradients turning onshore, in response to an upper-level trough approaching the Washington and northern Oregon coast. Mid-morning visible satellite imagery showed coastal low clouds penetrating into the northern and central coast range gaps and up the Columbia River into the northern Willamette Valley. Some low clouds had made it inland as far south as northern Linn County. The early onset of the onshore push has created some gradient-stacking this morning, which may persist into the afternoon. Rapid cooling aloft will yield high mixing heights this afternoon, if the marine clouds break up enough to allow for some surface heating. In any case, temperatures will cool to at least slightly below normal. Look for mixing heights to quickly drop below 3000 feet this evening, as more cool low-level marine air pours into the valley. TODAY'S FORECAST: Morning clouds giving way to partly sunny skies and much cooler. Slight chance of a light shower this afternoon, especially near the Cascade foothills. After a high temperature Wednesday of 90 degrees, today's high will only climb into the mid 70s. With any clearing, mixing heights should climb to around 3000 feet by midday and to more than 5000 feet from 2 p.m. through 5 p.m. Surface winds will be northwesterly at 5-10 mph. Transport winds will also turn northwesterly and increase to 10-15 mph this afternoon. Relative humidity levels will drop below 60% by midday and down to near 45% this afternoon. Salem sunset tonight: 9:00pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 69 75 77 66 Relative Humidity: 57% 47% 42% 58% Surface Wind Direction: 330 330 320 320 Surface Wind Speed: 6 7 9 12 Transport Wind Direction: 340 320 320 330 Transport Wind Speed: 7 10 15 18 Estimated Mixing Height: 3000 5500 5500 2500 Ventilation Index: 21 55 83 45 EXTENDED DISCUSSION: The upper-level trough is forecast to move across Washington and northern Oregon on Friday. Strong onshore flow will further cool the air mass and bring considerable marine clouds inland. There is a slight chance of morning drizzle or a light shower. Even with some afternoon clearing, high temperatures will only be in the 70-75 degree range. Temperatures will warm to near normal over the weekend, with morning clouds and afternoon sunshine. Another upper-level trough is forecast to move onshore early next week, bringing cooler-than-normal temperatures and a threat of light showers. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 29184 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 7 11:54:28 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 7 Jul 2011 11:54:28 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT THU JUL 7, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from now until 7:00 p.m. WEATHER DISCUSSION: A "marine push" began early this morning and was continuing at midday. Pressure gradients have turned strongly onshore, in response to an upper-level trough moving onto the Washington and northern Oregon coast. Much cooler air is pouring into the valleys of western Washington and northwestern Oregon with Willamette Valley temperatures mostly in the mid to upper 60s late this morning (about 5-10 degrees cooler than 24 hours ago). Late-morning visible satellite imagery showed coastal low clouds covering all of western Washington and extending as far south as interior Lane County in western Oregon. The marine clouds deck will only partially break up this afternoon, with the added lift from the approaching weak weather system also bringing a slight chance of sprinkles. Rainfall so far today has been limited to just few hundredths of an inch across the extreme north coast. The early morning onset of the "marine push" has created unfavorable gradient-stacking conditions, which may persist well into the afternoon. Cooling aloft will help maximum mixing heights climb to near 6000 feet by late this afternoon, as temperatures reach the low to mid 70s. Mixing heights should quickly drop below 3000 feet this evening, in response to more marine air pouring into the valley. TODAY'S FORECAST: Mostly cloudy and much cooler. Partial afternoon clearing. Slight chance of sprinkles, especially near the Cascade foothills. Surface winds: NW 5-12 mph Transport winds: NW increasing to 10-15 mph Salem's forecast high temperature: 75 degrees Relative humidity: Drops to 50% by around 2 p.m. Salem sunset tonight: 9:00pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 72 75 69 Relative Humidity: 50% 44% 49% Surface Wind Direction: 330 330 310 Surface Wind Speed: 8 10 12 Transport Wind Direction: 320 320 320 Transport Wind Speed: 12 14 18 Estimated Mixing Height: 5000 6000 2500 Ventilation Index: 60 84 45 EXTENDED DISCUSSION: The upper-level trough is forecast to move across Washington and northern Oregon on Friday. Strong onshore flow will further cool the air mass and bring considerable marine clouds inland. There is a slight chance of morning drizzle or a light shower. Even with some afternoon clearing, high temperatures will only be in the 70-75 degree range. Temperatures will warm to near normal over the weekend, with morning clouds and afternoon sunshine. Another upper-level trough is forecast to move onshore early next week, bringing cooler-than-normal temperatures and a threat of light showers by Tuesday and Wednesday. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 8 08:50:52 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 8 Jul 2011 08:50:52 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT FRI JUL 8, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 10:00 a.m. to 7:00 p.m. WEATHER DISCUSSION: An upper-level trough will move across southern British Columbia and northern Washington today with a cool but dry westerly flow aloft over Oregon. High pressure is building into northwestern Oregon and turning surface gradients from onshore to northerly. As a result, low clouds have cleared from the central and southern coast and are patchy in the central and southern Willamette Valley. Low clouds still blanket the north coast and the northern Willamette Valley, from northern Marion County to the Columbia River. The Salem sounding this morning showed northeasterly winds from 1-3000 feet above the surface. Offshore transport winds will continue to dry the air mass today and allow rapid clearing of the morning low clouds. Even with plenty of sunshine, high temperatures will be about 5 degrees below normal. TODAY'S FORECAST: Partly cloudy this morning. Sunny and a little breezy this afternoon. Surface winds: N 5-10 this morning; N 10-15 mph this afternoon Transport winds: NNE 10-15 mph this morning; NNE 15-20 mph this afternoon Salem's forecast high temperature: 75 degrees Maximum mixing height: 5000 feet Relative humidity: Drops to 60% by 10 a.m. and to near 30% by 5 p.m. Salem sunset tonight: 9:00pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 64 70 75 70 Relative Humidity: 47% 36% 31% 39% Surface Wind Direction: 360 360 360 360 Surface Wind Speed: 7 10 12 12 Transport Wind Direction: 020 020 020 020 Transport Wind Speed: 12 17 17 18 Estimated Mixing Height: 4000 4500 5000 3500 Ventilation Index: 48 77 85 63 EXTENDED DISCUSSION: The flow aloft will turn southwesterly and warm slightly on Saturday. Brief morning clouds will give way to sunshine with northerly transport winds and high temperatures returning to normal (near 80). Sunday looks to be another pleasant day, with near-normal temperatures. However, an upper-level trough will likely initiate a "marine push" Sunday afternoon, with transport winds turning northwesterly. A fairly impressive upper-level trough is forecast to move down the British Columbia coastline on Monday and park itself just off the Oregon Coast Tuesday and Wednesday, before coming onshore Thursday. That would bring mostly cloudy skies, cooler-than-normal temperatures, and a threat of showers to the region for most of the coming week. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 8 11:56:31 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 8 Jul 2011 11:56:31 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:55 AM PDT FRI JUL 8, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from now until 7:00 p.m. WEATHER DISCUSSION: An upper-level trough will move across southern British Columbia and northern Washington today with a cool but dry westerly flow aloft over Oregon. High pressure is building into northwestern Oregon; increasing the northwesterly gradients across the northern Willamette Valley and the northerly gradients across the central and southern valley. Late this morning, visible satellite imagery showed low clouds persisting over the northwestern corner of Oregon, extending about as far south and east as the Silverton Hills region. Skies were generally clear across the remainder of the state. Northwesterly surface winds should turn more northerly, with clearing skies, by early this afternoon. Above the surface, northeasterly transport winds will continue to dry the air mass today and allow for plenty of afternoon sunshine. However, yesterday's "marine push" forced a cool air mass into the region, so high temperatures will be about 5 degrees below normal. TODAY'S FORECAST: Sunny and a little breezy this afternoon. Surface winds: becoming N 10-15 mph this afternoon Transport winds: NE 15-20 mph this afternoon Salem's forecast high temperature: 75 degrees Maximum mixing height: 5000 feet Relative humidity: Drops to near 30% by 5 p.m. Salem sunset tonight: 9:00pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 70 75 70 Relative Humidity: 36% 31% 39% Surface Wind Direction: 360 360 360 Surface Wind Speed: 12 13 12 Transport Wind Direction: 030 030 030 Transport Wind Speed: 17 18 18 Estimated Mixing Height: 4500 5000 3500 Ventilation Index: 77 90 63 EXTENDED DISCUSSION: The flow aloft will turn southwesterly and warm slightly on Saturday. Brief morning clouds will give way to sunshine with northerly transport winds and high temperatures returning to normal (near 80). Sunday looks to be another pleasant day, with near-normal temperatures. However, an upper-level trough will likely initiate a "marine push" Sunday afternoon. Transport winds will turn northwesterly; initiating a general cool-down across western Oregon. A fairly impressive upper-level trough is forecast to move down the British Columbia coastline, on Monday, to just off the southern Oregon Coast by Wednesday. It is forecast to move inland, most likely across southern Oregon and northern California, Thursday and Friday. That would bring mostly cloudy skies, cooler-than-normal temperatures, and at least the threat of showers during much of next week. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Jul 11 08:46:50 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 11 Jul 2011 08:46:50 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT MON JUL 11, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 10:00 a.m. to 7:00 p.m. WEATHER DISCUSSION: Upper level trough has moved in over the state this morning with the center of the upper low over northern Vancouver Island. This low and trough will gradually move southeastward toward Oregon throughout the day. The result will be for the region to remain under the marine influence with below normal temperatures and mainly broken to overcast cloud cover. Transport wind flow will be mainly light southwesterly. However, strongest gradient stacking will be over the Cascades. The Salem sounding this morning showed the effects of last evening's marine push with the marine layer extending up to 7000 ft. Wind flow was south to SSW at 5-10 mph. Mixing level was below 1000 ft but with slow heating today mixing levels should reach 3000 ft by noon and up to 4500 ft by late afternoon. TODAY'S FORECAST: Mostly cloudy with light winds favoring SW during the afternoon. Surface winds: S 3-5 mph this morning; SSW-WSW 5-8 mph this afternoon Transport winds: S-SSW 6-10 mph this morning; SW 6-10 mph this afternoon Salem's forecast high temperature: 71 degrees Maximum mixing height: 4500 feet Relative humidity: Drops to near 50% by 4 p.m. Salem sunset tonight: 8:58pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 63 68 71 66 Relative Humidity: 65% 55% 49% 58% Surface Wind Direction: 200 220 260 270 Surface Wind Speed: 4 5 6 7 Transport Wind Direction: 190 220 230 260 Transport Wind Speed: 8 7 7 10 Estimated Mixing Height: 2200 4200 4500 3800 Ventilation Index: 18 29 32 38 EXTENDED DISCUSSION: Upper level low and trough move in closer to the state tomorrow bringing more clouds and the chance of some light showers. Temperatures will likely cool another 5-8 degrees from today. Wind flow will remain onshore, mainly from the SSW to W. Upper level low moves over the state on Wednesday continuing the chance of showers. Gradually, the low weakens but remains over the region through the remainder of the week. Any shower activity should decrease by Thursday but clouds and cooler than normal temperatures will remain. Wind flow will remain onshore with SSW to W winds through Thursday, turning more NW'erly by Friday. 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Jul 11 11:45:12 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 11 Jul 2011 11:45:12 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT MON JUL 11, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from now to 7:00 p.m. WEATHER DISCUSSION: Upper level trough has moved in over the state this morning with the center of the upper low over northern Vancouver Island. This low and trough will gradually move southeastward toward Oregon throughout the day. The result will be for the region to remain under the marine influence with below normal temperatures and mainly broken to overcast cloud cover. Transport wind flow will be mainly light southwesterly. Gradient stacking is strongest over the Cascades with 4.0 mb onshore flow from Salem to Redmond while only 1.1 mb onshore flow from Newport to Salem. Morning satellite picture shows a combination of marine low clouds over western Oregon as well as increasing higher clouds due to a disturbance moving in associated with the upper level trough. Some rain showers are showing up on radar over the eastern Pacific. However, expect the best chance of rain to occur tomorrow and Wednesday. TODAY'S FORECAST: Mostly cloudy with light SW winds through this afternoon. Surface winds: S-WSW 5-8 mph Transport winds: SW 6-10 mph Salem's forecast high temperature: 71 degrees Maximum mixing height: 4500 feet Relative humidity: Drops to near 50% by 4 p.m. Salem sunset tonight: 8:58pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 68 71 66 Relative Humidity: 55% 49% 58% Surface Wind Direction: 220 260 270 Surface Wind Speed: 6 6 7 Transport Wind Direction: 220 230 260 Transport Wind Speed: 7 7 10 Estimated Mixing Height: 4200 4500 3800 Ventilation Index: 29 32 38 EXTENDED DISCUSSION: Upper level low and trough move in closer to the state tomorrow bringing more clouds and the chance of some light showers. Temperatures will likely cool another 5-7 degrees from today. Wind flow will remain onshore, mainly from the SSW to W. Upper level low moves over the state on Wednesday continuing the chance of showers. Gradually, the low weakens but remains over the region through the remainder of the week. Any shower activity should decrease by Thursday but clouds and cooler than normal temperatures will remain. Wind flow will remain onshore with SSW to W winds through Thursday, turning more NW'erly by Friday. 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Jul 12 08:54:29 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 12 Jul 2011 08:54:29 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT TUE JUL 12, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 9:00 a.m. to 7:00 p.m. WEATHER DISCUSSION: An unseasonably strong upper-level trough is centered about 300 miles off the northern Oregon Coast this morning. An associated cold front was bringing cloudy skies and areas of light rain to the region. Mid-morning satellite imagery showed solid cloud-cover extending from well offshore eastward, across the Cascades, and into Central Oregon. The northern Willamette Valley has already received around one-tenth of an inch of rain. The upper-level trough is not forecast to move much today, so light rain should continue, at times, under cloudy skies. Temperatures will be about 15 degrees below normal. TODAY'S FORECAST: Cloudy with light rain at times. Additional rainfall totals around could exceed one-tenth (.10") of an inch. Surface winds: SSW 5 mph this morning; SW 5-8 mph this afternoon Transport winds: SSW 6-10 mph this morning; SW 10 mph this afternoon Salem's forecast high temperature: 66 degrees Maximum mixing height: 4500 feet Relative humidity: Remains above 65% all day Salem sunset tonight: 8:58pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 62 64 66 62 Relative Humidity: 78% 76% 68% 78% Surface Wind Direction: 200 210 230 260 Surface Wind Speed: 5 5 6 7 Transport Wind Direction: 200 220 250 260 Transport Wind Speed: 7 8 10 10 Estimated Mixing Height: 2700 4000 4500 3800 Ventilation Index: 19 32 45 38 EXTENDED DISCUSSION: The upper-level trough is forecast to moves over the state on Wednesday, before weakening Thursday and Friday. Look for showers to continue on Wednesday with some drying and warming on Thursday. By Friday, temperatures should recover to within about 5 degrees of normal with some afternoon sunshine. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 29184 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Jul 12 11:57:40 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 12 Jul 2011 11:57:40 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT TUE JUL 12, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from now until 7:00 p.m. WEATHER DISCUSSION: An unseasonably strong upper-level trough was centered about 150 miles west of the mouth of the Columbia River late this morning. An associated cold front moved across western Oregon early this morning, dropping generally from one-tenth to one-quarter of an inch of rain across Marion County and extreme northern Linn County. The highest amounts were near the Cascades foothills. The cold front has pushed into eastern Oregon, and rain has tapered off across the Willamette Valley. A composite of area Doppler radars shows that rainfall has tapered off, with most of the remaining activity near and over the northern Cascades. Satellite imagery continues show cloudy skies covering virtually all of western Oregon. Skies were partly cloudy east of the Cascades. Clouds were holding late-morning temperatures in the low 60s, across the Willamette valley, with surface reports confirming a few continuing areas of light rain. An embedded weather disturbance is forecast to rotate around the parent upper-level trough and onshore this afternoon. As it moves over northwestern Oregon, additional lifting of the moist air mass over the region should generate scattered showers. Most valley locations will likely pick up from a trace to a couple hundredths of an inch, but stronger showers could produce around one-tenth of an inch. High temperatures will be about 15 degrees below normal. TODAY'S FORECAST: Cloudy and unseasonably cool with scattered showers. Surface winds: SSW 5-8 mph this afternoon Transport winds: SW 10 mph this afternoon Salem's forecast high temperature: 66 degrees Maximum mixing height: 4500 feet Relative humidity: Remains above 65% all day Salem sunset tonight: 8:58pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 64 66 62 Relative Humidity: 76% 68% 78% Surface Wind Direction: 200 210 220 Surface Wind Speed: 5 6 7 Transport Wind Direction: 210 220 230 Transport Wind Speed: 8 10 10 Estimated Mixing Height: 4000 4500 2500 Ventilation Index: 32 45 25 EXTENDED DISCUSSION: The upper-level trough is forecast to move inland on Wednesday, weaken Thursday, and then lift northeastward out of the region on Friday. Look for showers to continue on Wednesday with slow drying and minor warming on Thursday. By Friday, temperatures should recover to within about 5 degrees of normal with some afternoon sunshine. Another cool trough is forecast to bring back a chance of showers over the weekend. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Jul 13 08:55:15 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 13 Jul 2011 08:55:15 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT Wed JUL 13, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 9:00 a.m. to 7:00 p.m. Prep burning is allowed from 12:00 p.m. to 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from 12:00 p.m. to 5:00 p.m. WEATHER DISCUSSION: An unseasonably strong upper-level trough dumped from one-tenth and one-third of an inch of rain, across the Willamette Valley, between Monday night and this morning, with the greatest totals near the Cascade foothills. The center of circulation was just off the southern Washington coast this morning with a continued moist southwesterly flow aloft over western Oregon. Mid-morning visible satellite imagery showed clouds covering most of western Oregon again this morning, but a few breaks in the clouds indicated that the air mass is beginning to dry out. Doppler radar showed a few light showers over the north coast range and possible sprinkles over the valley, especially near the Cascades foothills. The surface map showed weak southerly pressure-gradients across the Willamette Valley. The upper-level trough is forecast to weaken slightly today, as it slowly moves onshore across western Washington. The air aloft is cool, so daytime heating will destabilize the air mass; likely increasing the shower activity across the region. Surface and transport winds will veer to more westerly late this afternoon. Temperatures will be 5-10 degrees below normal. TODAY'S FORECAST: Mostly cloudy with a few showers. Areas of partial clearing, especially in the late-afternoon and evening. Additional rainfall totals less than one-tenth (.10") of an inch. Surface winds: S 5-8 mph this morning; becoming WSW 6-10 mph this afternoon Transport winds: SSW 10 mph this morning; becoming WSW 10 mph this afternoon Salem's forecast high temperature: 74 degrees Maximum mixing height: 5500 feet Relative humidity: Drops to 60% by noon and to near 40% by 5 p.m. Salem sunset tonight: 8:57pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 66 71 73 69 Relative Humidity: 63% 48% 43% 46% Surface Wind Direction: 190 210 260 280 Surface Wind Speed: 6 6 8 8 Transport Wind Direction: 210 230 270 280 Transport Wind Speed: 10 10 10 10 Estimated Mixing Height: 4000 5500 5500 3000 Ventilation Index: 40 55 55 30 EXTENDED DISCUSSION: The upper-level trough is forecast to weaken Thursday and Friday, as the main circulation center moves into southern British Columbia. That should bring generally dry weather and a few degrees of warming each day. High afternoon mixing heights and southwesterly transport winds may provide favorable burning conditions. Another upper-level trough is forecast to bring a weak cold front onshore Friday night and Saturday, with a renewed threat of light showers. A moist southwesterly flow aloft will continue the chance of showers through at least early next week with temperatures likely remaining below normal. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 30208 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Jul 13 11:42:19 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 13 Jul 2011 11:42:19 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:40 AM PDT WED JUL 13, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from now until 7:00 p.m. Prep burning is allowed from 12:00 p.m. to 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from 12:00 p.m. to 5:00 p.m. WEATHER DISCUSSION: The center of an unseasonably strong upper-level trough was over northwestern Washington, late this morning, with a continued moist southwesterly flow aloft over Oregon. Visible satellite imagery showed mostly cloudy skies over Western Oregon, where temperatures had only climbed into the low to mid 60s. With cool air aloft, daytime heating is destabilizing the air mass; leading to vertical cloud development. Late-morning Doppler radar showed an increase in both coverage and intensity of showers. The upper-level trough is forecast to weaken slightly today, as it continues to slowly move across northwestern Washington. However, the moist and increasingly unstable air mass will lead to scattered showers this afternoon, along with some sun-breaks. Temperatures will be 5-10 degrees below normal. TODAY'S FORECAST: Mostly cloudy with a few showers. Partial clearing. Additional rainfall totals mostly less than one-tenth (.10") of an inch. Surface winds: S 5-8 mph; becoming SW 6-10 mph later this afternoon Transport winds: SW 10 mph this afternoon Salem's forecast high temperature: 73 degrees Maximum mixing height: 5500 feet Relative humidity: Near 60% at noon; dropping to around 45% by 5 p.m. Salem sunset tonight: 8:57pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 69 72 69 Relative Humidity: 53% 46% 46% Surface Wind Direction: 210 260 280 Surface Wind Speed: 6 8 8 Transport Wind Direction: 230 270 280 Transport Wind Speed: 10 10 10 Estimated Mixing Height: 5500 5500 3000 Ventilation Index: 55 55 30 EXTENDED DISCUSSION: The upper-level trough is forecast to weaken Thursday and Friday, as the main circulation center moves into southern British Columbia and then Alberta. The threat of showers should greatly decrease by Thursday afternoon, and Friday looks to be a dry day. Temperatures will remain below normal but warm a few degrees each day. High afternoon mixing heights and southwesterly transport winds may provide favorable burning conditions. Another upper-level trough is forecast set up camp just offshore and swing a weak cold front inland early Saturday. That will bring a renewed threat of light showers and keep temperatures below normal. The upper-level trough is forecast to strengthen and remain near the west coast throughout most of next week; rotating several disturbances across the Pacific Northwest. That will maintain a treat of showers, at times, and keep temperatures moderate. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 30720 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 14 08:54:34 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 14 Jul 2011 08:54:34 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT THU JUL 14, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 9:00 a.m. to 7:00 p.m. Prep burning is allowed from 12:00 p.m. to 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from 12:00 p.m. to 5:00 p.m. WEATHER DISCUSSION: An upper-level trough was centered over northwestern Washington this morning. To the south of the circulation center, a moist west-southwesterly flow was producing cloudy skies, with areas of light rain, across western Washington. Considerable clouds extended southward into northwestern Oregon, with some showers along the north coast and over the northern coast range. The Silverton Hills region lies on the southern edge of the more solid cloud-cover this morning, with increasing amounts of clearing in the central and southern Willamette Valley. The Salem sounding this morning was almost identical to yesterday morning's sounding, showing an unseasonably cool and moist air mass over the region. The surface map also showed little change from yesterday, with weak southerly pressure gradients across the Willamette Valley. The upper-level trough is forecast to weaken slightly today, as it slowly moves eastward today. It will extend from north-central Washington to northwestern Oregon late this afternoon. The air aloft remains cool, so daytime heating will, once again, destabilize the air mass and lead to a few afternoon showers, mainly from the Silverton Hills region northward. Surface and transport winds will veer to more westerly late this afternoon. Skies should clear significantly this evening, as the upper-level trough moves east of the region. Temperatures will continue to be 5-10 degrees below normal. TODAY'S FORECAST: Partly sunny. Slight chance of a shower. Clearing skies this evening. Surface winds: S 5-8 mph this morning; becoming WSW 6-10 mph this afternoon Transport winds: SSW 10 mph this morning; becoming WSW 10 mph this afternoon Salem's forecast high temperature: 74 degrees Maximum mixing height: 6000 feet Relative humidity: Drops to 60% by noon and to near 43% by 5 p.m. Salem sunset tonight: 8:56pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 63 69 73 69 Relative Humidity: 66% 53% 43% 48% Surface Wind Direction: 190 210 260 290 Surface Wind Speed: 7 8 8 10 Transport Wind Direction: 200 210 260 270 Transport Wind Speed: 10 10 10 12 Estimated Mixing Height: 3000 5000 6000 3500 Ventilation Index: 30 50 60 42 EXTENDED DISCUSSION: A drier and slightly warmer westerly flow aloft is forecast on Friday. Low-level winds will remain onshore, so expect some morning marine low clouds to form in the northern Willamette Valley. With partly cloudy skies and some warming aloft, afternoon temperatures should reach the mid to upper 70s. Normal high temperatures are in the low 80s. High afternoon mixing heights and southwesterly transport winds may provide favorable burning conditions. Another upper-level trough is forecast set up camp just offshore this weekend. A weak cold front will swing inland early Saturday, bringing a renewed threat of light showers and slightly cooler temperatures. The flow aloft will turn southwesterly Sunday and Monday with the upper-level trough moving inland on Tuesday. That will maintain at least a treat of showers and keep temperatures below normal. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 31232 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 14 11:50:38 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 14 Jul 2011 11:50:38 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT THU JUL 14, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from now until 7:00 p.m. Prep burning is allowed from 12:00 p.m. to 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from 12:00 p.m. to 5:00 p.m. WEATHER DISCUSSION: An upper-level low-pressure area was centered over north-central Washington, late this morning, with an associated trough extending across western Washington and northwestern Oregon. So far today, showers have mostly been confined to the northern coast and coast range. However, afternoon heating will further destabilize the air mass and likely lead to more showers. Midday satellite imagery showed solid cloud-cover over western Washington and northwestern Oregon, from the coast range westward. Skies were mostly cloudy over the northern Willamette Valley and partly cloudy over the central and south valley. The Silverton Hills region is on the southern edge of where showers are likely to develop this afternoon. High temperatures will, once again, be 5-10 degrees below normal. The upper-level trough is forecast to weaken, as it continues to migrate slowly eastward this afternoon. Skies should begin to clear this evening, with surface and transport winds veering to more westerly, as the trough moves east of the Willamette Valley. TODAY'S FORECAST: Partly sunny. Slight chance of a shower. Clearing skies this evening. Surface winds: S 6-10 mph; becoming WSW 6-10 mph by this evening Transport winds: SSW 10 mph; becoming WSW 10 mph by this evening Salem's forecast high temperature: 74 degrees Maximum mixing height: 6000 feet Relative humidity: Drops to near 43% by 5 p.m. Salem sunset tonight: 8:56pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 69 73 69 Relative Humidity: 53% 43% 48% Surface Wind Direction: 210 260 290 Surface Wind Speed: 8 8 10 Transport Wind Direction: 210 260 270 Transport Wind Speed: 10 10 12 Estimated Mixing Height: 5000 6000 3500 Ventilation Index: 50 60 42 EXTENDED DISCUSSION: A drier and slightly warmer westerly flow aloft is forecast on Friday. Low-level winds will remain onshore, so expect morning clouds to give way to at least partly sunny skies in the afternoon. High temperatures should reach the mid to upper 70s. High afternoon mixing heights and southwesterly transport winds may provide favorable burning conditions. Another upper-level trough is forecast set up camp just offshore this weekend. A weak front will renew the threat of light showers by early Saturday, with another weather disturbance rotating onshore Sunday afternoon. The trough is forecast to weaken Monday and Tuesday, only to be replaced by another upper-level trough next Wednesday and Thursday. Look for a continued threat of showers and generally below normal temperatures through next week. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 30208 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 15 08:56:01 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 15 Jul 2011 08:56:01 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT FRI JUL 15, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 10:00 a.m. to 7:00 p.m. Prep burning is allowed from 10:00 a.m. to 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from 10:00 a.m. to 5:00 p.m. WEATHER DISCUSSION: The upper-level trough that brought cool and showery weather to the region for the past couple of days has temporarily weakened. The Salem sounding this morning showed minor warming and drying of the air mass from the surface up to 10,000 feet. Onshore surface pressure gradients have relaxed, so most of the Willamette Valley was already seeing partly to mostly sunny skies at mid-morning. More sunshine will help high temperatures climb to near normal this afternoon. The next in a series of weather disturbances is rapidly approaching the coastline and shows up well on infrared satellite imagery about 200 miles off the Washington and northern Oregon coast. High clouds from this system are already reaching the northern Oregon coast. Visible satellite imagery shows low clouds covering the entire coastal strip, but they only extend inland to about the crest of the coast range. Some light rain was falling on the extreme north coast at Astoria. look for increasing clouds this afternoon with transport winds veering to more westerly. The combined lift from daytime heating and the approaching weather system will make for good smoke dispersal conditions today. Clouds will lower and thicken this evening with light rain likely moving into the Willamette Valley by the early morning hours on Saturday. TODAY'S FORECAST: Mostly sunny early with increasing clouds in the afternoon. Salem's forecast high temperature: 80 degrees Surface winds: S 3-7 mph this morning; becoming WSW 6-10 mph this afternoon Transport winds: SSW 10 mph this morning; becoming WSW 12 mph this afternoon Maximum mixing height: 5500 feet Relative humidity: Drops to 60% by 10 a.m. and to near 38% by 5 p.m. Salem sunset tonight: 8:56pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 69 76 79 72 Relative Humidity: 55% 44% 38% 53% Surface Wind Direction: 190 210 250 270 Surface Wind Speed: 5 6 7 8 Transport Wind Direction: 200 220 250 270 Transport Wind Speed: 10 10 12 14 Estimated Mixing Height: 3500 4500 5500 2500 Ventilation Index: 35 45 66 35 EXTENDED DISCUSSION: An upper-level trough is forecast set up camp just offshore this weekend. A weak front will bring light rain to the region on Saturday, with another weather disturbance maintaining at least a chance of showers Sunday through Tuesday. Yet another system is forecast for late next week, so it appears as if the cool damp weather pattern will continue through next week. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 30720 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 15 11:55:56 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 15 Jul 2011 11:55:56 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:55 AM PDT FRI JUL 15, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are now until 7:00 p.m. Prep burning is allowed from now until 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from now until 5:00 p.m. WEATHER DISCUSSION: A dry and warmer west-southwesterly flow aloft has set up ahead of another cold front that is rapidly approaching the coastline. Late-morning satellite imagery showed cloudy skies covering the coast but mostly sunny skies east of the coast range. Some light rain fell at times this morning at Astoria, on the extreme northern coast, but dry weather prevailed across the rest of the state. Late this morning, Willamette Valley temperatures were approaching 70 degrees (about 3-5 degrees warmer than 24 hours ago). High temperatures should approach the 80 degree mark this afternoon, which is still a couple of degrees below normal. Look for increasing clouds this afternoon with transport winds veering to more westerly. Mixing heights should climb above 5000 feet for good smoke dispersal conditions. TODAY'S FORECAST: Increasing clouds but warmer. Salem's forecast high temperature: 80 degrees Surface winds: S 3-7 mph; becoming WSW 5-10 mph by late this afternoon Transport winds: SSW 5-9 mph; becoming SW 7-12 mph by late this afternoon Maximum mixing height: 5500 feet Relative humidity: Drops to near 38% by 5 p.m. Salem sunset tonight: 8:56pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 76 79 72 Relative Humidity: 44% 38% 53% Surface Wind Direction: 210 250 270 Surface Wind Speed: 6 7 8 Transport Wind Direction: 220 250 270 Transport Wind Speed: 8 10 12 Estimated Mixing Height: 4500 5500 2500 Ventilation Index: 36 55 30 EXTENDED DISCUSSION: A cold front will likely spread rain across the northern Willamette Valley in the pre-dawn hours Saturday. Steady rain should turn to showers by Saturday afternoon. This system has a fair amount of moisture with it, for mid July, so rainfall totals could locally exceed one-quarter of an inch. Cool weather, with at least a chance for showers, will continue into the middle of next week. An upper-level trough is forecast set up camp, just offshore, Sunday and Monday, before swinging inland on Tuesday. That will likely be followed by another upper-level trough on Wednesday. Some drying and warming of the air mass is forecast for Thursday, as the upper-level trough exits to the east. The next upper-level trough is forecast to swing inland a little further to the north, into southern British Columbia, on Friday. That could set up a favorable burning pattern, if any fields are ready. There are indications that a drier and warmer weather pattern may be setting up beginning about Monday, July 25th, so summer may be on the way. Have a great weekend. 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 30720 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Jul 18 08:47:10 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 18 Jul 2011 08:47:10 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT MON JUL 18, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is not allowed. Propane flaming is allowed from 1:00pm to 5:00pm. WEATHER DISCUSSION: Persistent upper low and frontal systems brought significant rainfall to the Willamette Valley this weekend with totals ranging from around a half to one inch. This is an event rarely seen in the region during the middle of July. Upper low circulating off the northern California coast will continue to give a threat of showers to the area through this afternoon before weakening and shifting slowly eastward on Tuesday. Expect a little more sunshine today but still generally cloudy skies. Temperatures will warm over yesterday's cool 60s temperatures to get into the 70s this afternoon. Morning upper air sounding over Salem generally showed a moist and stable atmosphere with low level winds northerly at 5-10 mph shifting to easterly between 3000-4000 ft, then to southerly by 7000-8000 ft. This variable wind pattern is quite common with upper level lows near the region. As this low weakens, wind flow should consolidate to a more northwesterly flow up through the lower atmosphere. Surface pressure gradients are quite weak and from the north this morning but afternoon heating will slowly turn the gradient more onshore. TODAY'S FORECAST: Fog and low clouds early, becoming mostly cloudy with a chance of showers this afternoon. Salem's high temperature today will be near 76. Relative humidity drops to 50% by 4pm. Minimum relative humidity 48%. Surface winds: Light northerly winds turning NW'erly during the afternoon. Transport winds: NNW to N at 3-7 mph, turning NW'erly at 6-10 mph during the afternoon and evening. Maximum mixing height: Mixing below 2000 ft before noon, rising to 4500 ft by late afternoon. Sunset tonight: 8:53 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 66 73 76 69 Relative Humidity: 70% 53% 48% 61% Surface Wind Direction: 360 340 310 290 Surface Wind Speed: 5 5 7 7 Transport Wind Direction: 360 330 320 310 Transport Wind Speed: 5 5 7 10 Estimated Mixing Height: 1500 3500 4500 2000 Ventilation Index: 8 18 32 20 EXTENDED DISCUSSION: Even though today's upper low gradually weakens and moves through on Tuesday, the upper level pattern will remain generally trough-like through the week. Expect continued cloudy skies, especially during the morning under onshore flow. Clouds will break up more in the afternoon but temperatures will warm at best to close to normal, but more likely below normal. Another impulse moves through the trough pattern early Thursday, increasing the onshore flow and bringing another chance of light showers. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Jul 18 08:56:01 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 18 Jul 2011 08:56:01 -0700 Subject: [willamette-fcst] (no subject) Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT MON JUL 18, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is not allowed. Propane flaming is allowed from 1:00pm to 5:00pm. WEATHER DISCUSSION: Persistent upper low and frontal systems brought significant rainfall to the Willamette Valley this weekend with totals ranging from around a half to one inch. This is an event rarely seen in the region during the middle of July. Upper low circulating off the northern California coast will continue to give a threat of showers to the area through this afternoon before weakening and shifting slowly eastward on Tuesday. Expect a little more sunshine today but still generally cloudy skies. Temperatures will warm over yesterday's cool 60s temperatures to get into the 70s this afternoon. Morning upper air sounding over Salem generally showed a moist and stable atmosphere with low level winds northerly at 5-10 mph shifting to easterly between 3000-4000 ft, then to southerly by 7000-8000 ft. This variable wind pattern is quite common with upper level lows near the region. As this low weakens, wind flow should consolidate to a more northwesterly flow up through the lower atmosphere. Surface pressure gradients are quite weak and from the north this morning but afternoon heating will slowly turn the gradient more onshore. TODAY'S FORECAST: Fog and low clouds early, becoming mostly cloudy with a chance of showers this afternoon. Salem's high temperature today will be near 76. Relative humidity drops to 50% by 4pm. Minimum relative humidity 48%. Surface winds: Light northerly winds turning NW'erly during the afternoon. Transport winds: NNW to N at 3-7 mph, turning NW'erly at 6-10 mph during the afternoon and evening. Maximum mixing height: Mixing below 2000 ft before noon, rising to 4500 ft by late afternoon. Sunset tonight: 8:53 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 66 73 76 69 Relative Humidity: 70% 53% 48% 61% Surface Wind Direction: 360 340 310 290 Surface Wind Speed: 5 5 7 7 Transport Wind Direction: 360 330 320 310 Transport Wind Speed: 5 5 7 10 Estimated Mixing Height: 1500 3500 4500 2000 Ventilation Index: 8 18 32 20 EXTENDED DISCUSSION: Even though today's upper low gradually weakens and moves through on Tuesday, the upper level pattern will remain generally trough-like through the week. Expect continued cloudy skies, especially during the morning under onshore flow. Clouds will break up more in the afternoon but temperatures will warm at best to close to normal, but more likely below normal. Another impulse moves through the trough pattern early Thursday, increasing the onshore flow and bringing another chance of light showers. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Jul 18 11:48:04 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 18 Jul 2011 11:48:04 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT MON JUL 18, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from now to 7:00pm. Prep burning is not allowed. Propane flaming is allowed from 2:00pm to 5:00pm. WEATHER DISCUSSION: Upper low circulating off the northern California coast will continue to give some showers to the area through this afternoon before weakening and shifting slowly eastward on Tuesday. Expect a little more sunshine today but still generally cloudy skies. Temperatures will warm over yesterday's cool 60s temperatures to get into the 70s this afternoon. Satellite picture and radar show clouds and showers developing and moving up from the south late this morning. With the likelihood of showers increasing I've lowered expected temperatures and increased humidities this afternoon. Pressure gradients are slowly increasing onshore with .8 mb onshore from Newport to Salem and 1.2 mb onshore from Salem to Redmond. TODAY'S FORECAST: Mostly cloudy with scattered showers this afternoon. Salem's high temperature today will be near 74. Relative humidity: Minimum relative humidity 58%. Surface winds: NW to N at 5-8 mph. Transport winds: NW'erly at 6-10 mph during the afternoon and evening. Maximum mixing height: 4500 ft by late afternoon. Sunset tonight: 8:53 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 71 74 68 Relative Humidity: 63% 58% 71% Surface Wind Direction: 340 310 290 Surface Wind Speed: 5 7 7 Transport Wind Direction: 330 320 310 Transport Wind Speed: 5 7 10 Estimated Mixing Height: 3500 4500 2000 Ventilation Index: 18 32 20 EXTENDED DISCUSSION: Even though today's upper low gradually weakens and moves through on Tuesday, the upper level pattern will remain generally trough-like through the week. Expect continued cloudy skies and a possible shower, especially during the morning under onshore flow. Clouds will break up more in the afternoon but temperatures will likely remain 5-10 degrees below normal. Another impulse moves through the trough pattern early Thursday, increasing the onshore flow and bringing another chance of light showers. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Jul 19 08:42:44 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 19 Jul 2011 08:42:44 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:40 AM PDT TUE JUL 19, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from 9:00am to 7:00pm. Prep burning is allowed from 12:00pm to 2:00pm with a 50 acre limit. Propane flaming is allowed from 11:00am to 5:00pm. WEATHER DISCUSSION: Upper level trough will finally move through the region this morning leaving cool, NW'rly flow over the region through this afternoon and evening. A few showers are still possible this morning before dissipating this afternoon. Onshore flow will remain fairly moderate today keeping clouds from breaking up too much and keeping temperatures a little cooler than yesterday. Morning upper air sounding over Salem generally showed a deep marine layer to 14,000 ft with minor stability near the surface. This stable layer should dissipate by mid morning, allowing mixing heights to rise to 5000 ft by noon. Surface and transport winds show a W to NW flow. Pressure gradients are over 4 mb from Newport to Redmond with even gradient stacking in the Coast Range and Cascades. TODAY'S FORECAST: Mostly cloudy with a chance of showers. Chance of showers decreases this afternoon. Salem's high temperature today will be near 71. Relative humidity drops to 50% by 4pm. Minimum relative humidity 49%. Surface winds: W to NW at 6-12 mph. Transport winds: W to NW at 10-15 mph. Maximum mixing height: 5000+ ft. Sunset tonight: 8:53 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 66 70 71 66 Relative Humidity: 67% 54% 49% 54% Surface Wind Direction: 280 280 280 290 Surface Wind Speed: 6 8 11 10 Transport Wind Direction: 290 280 280 280 Transport Wind Speed: 10 12 14 13 Estimated Mixing Height: 4000 5000+ 5000+ 3500 Ventilation Index: 40 60 70 46 EXTENDED DISCUSSION: Upper level pattern remains somewhat trough-like on Wednesday with onshore flow weakening and turning a little more northerly. Next upper level low drops down from north of Vancouver Island on Thursday and strengthens the onshore flow again. Expect a chance of light showers or sprinkles but not like the past weekend. Trough moves off to the east Friday giving way to a weak ridge for Friday afternoon and Saturday. Winds turn northerly again. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 29184 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Jul 19 11:41:08 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 19 Jul 2011 11:41:08 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:40 AM PDT TUE JUL 19, 2011 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: Upper level trough is moving east of the region and will leave cool, NW'erly flow over the area through this afternoon and evening. Air mass will be mostly unstable. Onshore flow will remain fairly moderate today keeping clouds from breaking up too much and keeping temperatures a little cooler than yesterday. Radar is showing this morning's showers dissipating and moving east of the region. Would not likely see anymore shower activity this afternoon. Satellite picture shows extensive cloud cover over western Oregon with little noticeable breakup. Pressure gradients are onshore at 1.4 mb Newport to Salem and onshore at 2.2 mb from Salem to Redmond. TODAY'S FORECAST: Mostly cloudy. Salem's high temperature today will be near 71. Relative humidity drops to 50% by 4pm. Minimum relative humidity 49%. Surface winds: W to NW at 6-12 mph. Transport winds: W to NW at 10-15 mph. Maximum mixing height: 5000+ ft. Sunset tonight: 8:53 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 70 71 66 Relative Humidity: 54% 49% 57% Surface Wind Direction: 280 280 290 Surface Wind Speed: 8 11 10 Transport Wind Direction: 280 280 280 Transport Wind Speed: 12 14 13 Estimated Mixing Height: 5000+ 5000+ 3500 Ventilation Index: 60 70 46 EXTENDED DISCUSSION: Upper level pattern remains somewhat trough-like on Wednesday with onshore flow weakening and turning a little more northerly. Next upper level low drops down from north of Vancouver Island on Thursday and strengthens the onshore flow again. Expect a chance of light showers or sprinkles but not like the past weekend. Trough moves off to the east Friday giving way to a weak ridge for Friday afternoon and Saturday. Temperatures warm and winds turn northerly again. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Jul 20 08:47:53 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 20 Jul 2011 08:47:53 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT WED JUL 20, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 10:00 a.m. to 7:00 p.m. Prep burning is allowed from 11:00 a.m. until 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from 11:00 a.m. until 5:00 p.m. WEATHER DISCUSSION: The Pacific Northwest is still under the influence of a broad upper-level trough. A deep marine layer remains over western Oregon this morning, but the onshore flow weakened enough overnight to allow for some sunshine this morning across much of the Willamette Valley. The surface map shows weak northerly pressure-gradients across most of western Oregon. The exception is along the north coast, where an approaching weather system has already turned gradients weakly southerly and brought in a solid deck of marine clouds. The Salem sounding this morning showed slight warming above 5000 feet and slight cooling below 5000 feet, compared to yesterday morning. That makes the atmosphere is a bit more stable today. Daytime convection will be more limited, so expect just partly cloudy skies this afternoon. The air aloft is still cooler-than-normal for mid-July, so mixing heights will be quite high this afternoon. Look for northerly transport winds to turn onshore this afternoon, in response to a weak weather system moving onto the north coast. That system will thicken the marine layer overnight, with a chance of drizzle or light showers by Thursday morning. TODAY'S FORECAST: Sunny early; becoming partly cloudy by this afternoon. Warmer. Salem's high temperature today will be near 78 degrees (normal is 82). Relative humidity drops to 60% by 11 a.m. and the near 36% by 5 p.m. Surface winds: N 3-7 this morning; becoming NW 5-10 this afternoon. Transport winds: N 3-7 this morning; becoming NW at 7-13 mph this afternoon. Mixing height: Rises above 3000 feet by 11 a.m. and above 5000 feet by 2 p.m. Sunset tonight: 8:52 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 68 75 78 70 Relative Humidity: 57% 43% 36% 51% Surface Wind Direction: 360 320 310 300 Surface Wind Speed: 4 6 7 10 Transport Wind Direction: 360 320 300 300 Transport Wind Speed: 4 7 11 15 Estimated Mixing Height: 3200 5200 6200 2500 Ventilation Index: 13 36 68 38 EXTENDED DISCUSSION: One weak weather system will bring a chance of drizzle or light showers Thursday morning, with another system maintaining the chance of showers Thursday afternoon and evening. A drier northwesterly flow aloft is forecast for Friday, as the upper-level trough finally lifts into southwestern Canada. The flow aloft will turn southwesterly over the weekend, as the next upper-level trough sets up camp a little farther offshore. That will bring dry and warmer weather to the region with high temperatures climbing into the mid 80s. The trough is forecast to move onshore Monday and remain over the region through next Wednesday. That will renew the threat of showers and cool temperatures back below normal. Dry and warmer weather is forecast for next Thursday and Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 31232 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Jul 20 11:54:05 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 20 Jul 2011 11:54:05 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT WED JUL 20, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from now until 7:00 p.m. Prep burning is allowed from now until 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from now until 5:00 p.m. WEATHER DISCUSSION: The Pacific Northwest is still under the influence of a broad upper-level trough with a deep marine layer over western Oregon. Daytime heating is already lifting the moist air mass and producing some cumulus cloud development. However, the aim mass aloft has warmed slightly, since Tuesday, making it more stable. That should inhibit any shower development today and allow high temperatures to warm about 5-8 degrees compared to yesterday. The air aloft is still cooler-than-normal for mid-July, so surface heating will lead to high afternoon mixing heights. Look for light northerly transport winds to increase and back to northwesterly later this afternoon, in response to a weak weather system moving onto the north coast. As that system comes onshore, it will thicken the marine layer overnight and bring back a chance of drizzle or light showers by Thursday morning. TODAY'S FORECAST: Partly cloudy and warmer. Salem's high temperature today will be near 78 degrees (normal is 82). Relative humidity drops to near 36% by 5 p.m. Surface winds: N 4-8 mph; becoming NW 5-10 mph this afternoon. Transport winds: N 4-8 mph; becoming NW at 7-13 mph this afternoon. Mixing height: Rises above 5000 feet by 2 p.m. Sunset tonight: 8:52 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 75 78 69 Relative Humidity: 43% 36% 57% Surface Wind Direction: 340 330 300 Surface Wind Speed: 6 7 10 Transport Wind Direction: 340 320 300 Transport Wind Speed: 7 11 15 Estimated Mixing Height: 5200 6200 2000 Ventilation Index: 36 68 30 EXTENDED DISCUSSION: A weak weather system will bring a chance of drizzle or light showers Thursday morning, with a second system maintaining a chance of showers Thursday afternoon and evening. A dry northwesterly flow aloft is forecast for Friday, as the upper-level trough finally lifts into southwestern Canada. Temperatures will remain below normal. A warmer southwesterly flow aloft is forecast for this weekend. That will bring dry weather with high temperatures climbing into the mid to upper 80s. The trough is forecast to move onshore Monday and remain over the region through next Wednesday. Although the threat of showers will this system will be minimal, it will increase the onshore flow and drop temperatures back into the 70s. Dry weather is forecast for next Thursday and Friday with temperatures returning to near normal (low 80s). The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 30720 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 21 08:47:20 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 21 Jul 2011 08:47:20 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT THU JUL 21, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 12:00 p.m. to 7:00 p.m. Prep burning is allowed from 12:00 p.m. until 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from 11:00 a.m. until 5:00 p.m. WEATHER DISCUSSION: The Pacific Northwest is under the influence of an unseasonably strong upper-level trough. After a brief warm-up yesterday, a weak weather system moved onshore early this morning and deepened the marine layer across western Oregon. Visible satellite imagery showed marine low clouds covering all of western Washington and extending south across most of western Oregon. Areas of light drizzle were falling in the northern and central Willamette Valley. The morning surface analysis showed weak southerly pressure-gradients across the Willamette Valley where surface reports indicated mostly southerly winds at 5-10 mph. The Salem sounding this morning had a similar temperature profile to yesterday, but there was a marked shift in the transport winds from northwesterly to southwesterly. Low-level southwesterly flow will slowly veer to westerly, by late this afternoon, as a second weak weather system swings onshore. Skies should stay mostly cloudy with an ongoing threat of light showers. However, even slight clearing will allow high temperatures to climb into the low 70s, since the sun angle is so high this time of the year. TODAY'S FORECAST: Mostly cloudy & cooler. Chance of drizzle and/or light showers. Salem's high temperature today will be near 72 degrees (normal is 83). Relative humidity drops to 60% about 12 p.m. and to near 50% by 5 p.m. Surface winds: S 5-10 mph this morning; W 5-10 mph later this afternoon. Transport winds: SW 10 mph this morning; W 10-15 mph later this afternoon. Mixing height: Rises to 3000 feet about 11 a.m. and to 4500 feet by 5 p.m. Salem's sunset tonight: 8:51 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 66 69 72 67 Relative Humidity: 65% 57% 51% 61% Surface Wind Direction: 190 220 270 300 Surface Wind Speed: 5 6 8 10 Transport Wind Direction: 210 240 270 310 Transport Wind Speed: 10 10 13 15 Mixing Height: 3000 4000 4500 2500 Ventilation Index: 30 40 59 38 EXTENDED DISCUSSION: A drier northwesterly flow aloft is forecast for Friday, as the upper-level trough shifts east of the region. Morning marine clouds should give way to mostly sunny skies in the afternoon with transport winds turning northerly and temperatures recovering into the upper 70s. A flat ridge will move over Oregon Saturday for continued warming and drying of the air mass. The flow aloft will turn southwesterly on Sunday, as the next upper-level trough approaches the coastline. High temperatures may approach 90 degrees with transport winds turning southwesterly in the afternoon. As the upper-level trough comes onshore Monday, a significant marine push will cool temperatures back to normal. A broad upper-lever trough is forecast to remain over the region for the duration of next week. It looks generally dry, but onshore flow will likely keep temperatures below normal. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 31744 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 21 11:40:28 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 21 Jul 2011 11:40:28 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:40 AM PDT THU JUL 21, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 12:00 p.m. to 7:00 p.m. Prep burning is allowed from 12:00 p.m. until 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from now until 5:00 p.m. WEATHER DISCUSSION: A weak weather system moved onshore early this morning and deepened the marine layer across western Oregon. Late-morning visible satellite imagery showed marine low clouds continuing to blanket all of western Washington and the northern two-thirds of western Oregon. Surface pressure gradients are still mostly southerly in the Willamette valley but are turning more westerly along the northern and central coast. Light rain fell this morning over the northwestern corner of the state elray this morning. Astoria picked up about one-tenth of an inch of rain with locally a couple of hundredths of an inch falling in the extreme northern Willamette Valley. Light drizzle fell as far south as the Silverton Hills area. Not much in the way of precipitation was falling late this morning. Doppler radar was showing possible sprinkles in the northern coastal range and near the extreme northern Cascades. Low-level southerly winds will turn more westerly, by late this afternoon, as the parent upper-level trough swings another weak weather system onshore. Skies should stay mostly cloudy with a slight chance of light showers. The weak weather system may help to partially break up the marine clouds, which would allow maximum temperatures to climb into the low 70s. TODAY'S FORECAST: Mostly cloudy & cooler. Chance of light showers. Salem's high temperature today will be near 72 degrees (normal is 83). Relative humidity drops to near 50% by 5 p.m. Surface winds: S 10 mph; veering to W 10 mph later this afternoon. Transport winds: SW 10-15 mph; veering to W 10-15 mph later this afternoon. Mixing height: Rising to 4500 feet by 5 p.m. Salem's sunset tonight: 8:51 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 69 72 67 Relative Humidity: 57% 51% 61% Surface Wind Direction: 220 270 290 Surface Wind Speed: 10 10 10 Transport Wind Direction: 240 270 300 Transport Wind Speed: 12 13 15 Mixing Height: 4000 4500 2500 Ventilation Index: 48 59 38 EXTENDED DISCUSSION: A drier northwesterly flow aloft is forecast for Friday, as the upper-level trough shifts east of the region. Morning marine clouds should give way to mostly sunny skies in the afternoon. Transport winds will turn northerly, and temperatures should recover into the upper 70s. A flat ridge will move over Oregon Saturday for continued warming and drying of the air mass. The flow aloft will turn southwesterly on Sunday, as the next upper-level trough approaches the coastline. Sunny skies and warming aloft will combine to lift high temperatures to around 90 degrees. However, the warm-up will be short-lived. Transport winds are forecast to turn southwesterly Sunday afternoon, in response to the approaching trough. A significant marine push will cool temperatures back to normal on Monday and introduce at least a slight chance of showers. A chance of showers continues through Tuesday morning. A generally dry westerly flow aloft may present burning opportunities, later in the week, with varying degrees of onshore flow and moderate temperatures. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 31744 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 22 08:42:41 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 22 Jul 2011 08:42:41 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:40 AM PDT FRI JUL 22, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are 11:00 a.m. to 7:00 p.m. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: An upper-level trough moved east of the Cascades overnight and was pushing into northern Idaho and western Montana this morning. A drier northwesterly flow aloft has set up over western Oregon. Near the surface, onshore flow is decreasing and turning northerly, especially in the northern Willamette Valley. Mid-morning visible satellite imagery showed considerable marine low clouds covering mainly the central and southern Willamette Valley with clearing skies in the north valley. This morning's sounding over Salem revealed a much drier air mass than 24 hours ago. There was still enough moisture to form marine clouds from 3000-4500 feet. However, winds below 4500 feet had already turned mostly offshore, so look for morning clouds to quickly give way to sunny skies. The air mass aloft is stable but still cooler than normal. Afternoon temperatures will warm into the upper 70s. TODAY'S FORECAST: Morning clouds, then sunny and warmer. Increasing northerly winds. Salem's high temperature today will be near 79 degrees (normal is 83). Relative humidity drops to near 50% about 11 a.m. and to near 30% by 5 p.m. Surface winds: N 5-10 mph this morning; N 10-15 mph this afternoon. Transport winds: N 10 mph this morning; NNE 12-15 mph this afternoon. Mixing height: Rises to 3000 feet by 11 a.m. and to 5500 feet by 5 p.m. Salem's sunset tonight: 8:50 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 68 75 78 73 Relative Humidity: 51% 37% 31% 41% Surface Wind Direction: 360 360 005 010 Surface Wind Speed: 8 10 12 12 Transport Wind Direction: 010 010 015 020 Transport Wind Speed: 10 12 13 15 Mixing Height: 3200 5000 5500 3000 Ventilation Index: 32 60 72 45 EXTENDED DISCUSSION: A flat ridge will move over Oregon Saturday for continued warming and drying of the air mass. High temperatures will likely climb into the mid 80s. The flow aloft will turn southwesterly on Sunday, as the next upper-level trough approaches the coastline. High temperatures may approach 90 degrees. As the upper-level trough comes onshore Monday, a mostly dry marine push will cool temperatures back to normal. A broad upper-lever trough is forecast to remain over the region through next week. Temperatures will cool to below normal Tuesday and Wednesday but may recover to near or slightly above normal by Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 31232 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 22 11:55:02 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 22 Jul 2011 11:55:02 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:54 AM PDT FRI JUL 22, 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from now until 7:00 p.m. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: A west-northwesterly flow aloft is slowly drying and warming the air mass over Oregon. Late-morning visible satellite imagery showed partly cloudy skies over the western valleys, with mostly clear skies over the coast and Cascades. Valley temperatures were mostly in the mid 60s with north winds up to 10 mph. With high pressure continuing to push into northwestern Oregon, and a surface thermal trough building into extreme southwestern Oregon, northerly surface and transport winds will likely turn slightly offshore by late this afternoon. That will promote clearing skies and help valley temperatures climb into the middle and upper 70s (still 5-8 degrees below normal). TODAY'S FORECAST: Clearing skies and slightly warmer. Increasing north to northeasterly winds. Salem's high temperature today will be near 78 degrees (normal is 83). Relative humidity drops to near 30% by 5 p.m. Surface winds: N 10-15 mph this afternoon. Transport winds: NNE 12-15 mph this afternoon. Mixing height: Rising to 5500 feet by 5 p.m. Salem's sunset tonight: 8:50 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 74 77 73 Relative Humidity: 37% 31% 41% Surface Wind Direction: 360 005 010 Surface Wind Speed: 10 12 12 Transport Wind Direction: 010 015 020 Transport Wind Speed: 12 13 15 Mixing Height: 5000 5500 3000 Ventilation Index: 60 72 45 EXTENDED DISCUSSION: A flat ridge will move over Oregon Saturday for continued warming and drying of the air mass. High temperatures will likely climb into the mid 80s. The flow aloft will further warm and turn southwesterly on Sunday. Highs will likely approach 90 degrees. An upper-level trough is forecast to come onshore Monday. The resulting marine push will bring increasing clouds and cool temperatures back to normal. There is a slight chance of drizzle or very light showers Monday night and early Tuesday, as far south as the Silverton Hills, but this system appears as if it will be mainly dry. High temperatures on Tuesday will drop back into the middle 70s. A broad upper-lever trough will maintain mostly dry weather for the remainder of next week. Gradual warming aloft will help temperatures recover to near or slightly above normal by Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 30720 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Jul 25 08:41:59 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 25 Jul 2011 08:41:59 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:40 AM PDT MON JUL 25 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is not allowed. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: An upper-level trough will move through the region today. It brought a moderate marine push to the area last evening. Expect a considerably cooler day today with temperatures around 15 degrees lower than yesterday. A chance of sprinkles are possible this morning but the marine cloud cover will slowly break up to partly to mostly cloudy skies this afternoon. Air mass will be generally unstable today with considerably cooler air aloft from the upper trough. This morning's sounding over Salem showed the moist marine layer up to around 3000 ft. Since the marine air isn't too thick it should break up some this afternoon. Wind flow is quite light showing that most of the energy of the marine push has pushed east of the region. Gradient stacking confirms this with the main gradient stacking over the Cascades. This should gradually equalize this afternoon. TODAY'S FORECAST: Salem's high temperature today will be near 74. Minimum relative humidity 51%. Surface winds: SW 3-6 mph during the morning becoming SW to WNW at 5-9 mph this afternoon. Transport winds: SW at 4-7 mph during the morning becoming W to NW at 6-10 mph during the afternoon. Mixing height: Rising to 4000 ft by noon and up to 5000 ft during the afternoon. Sunset tonight: 8:47 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 66 71 74 68 Relative Humidity: 68% 57% 51% 63% Surface Wind Direction: 220 230 280 290 Surface Wind Speed: 4 5 7 8 Transport Wind Direction: 260 280 300 320 Transport Wind Speed: 5 6 8 10 Estimated Mixing Height: 3800 4500 5000 2500 Ventilation Index: 19 27 40 25 EXTENDED DISCUSSION: Upper level trough will move by to the east of the state tonight as it weakens. Expect gradual warming. A minor ridge tries to move in on Wednesday but flattens as it moves in, leaving the region under westerly flow aloft. Temperatures gradually return to seasonal normals. Wind flow turns northerly through the remainder of the week with slight onshore flow during the later afternoon. However, it appears it won't be enough to make for good burning conditions. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 29184 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Jul 25 11:43:06 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 25 Jul 2011 11:43:06 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:40 AM PDT MON JUL 25 2011 BURN ADVISORY: Recommended burn times for agricultural burning are from 12:00pm to 7:00pm. Prep burning is not allowed. Propane flaming is allowed from 12:00pm to 5:00pm. WEATHER DISCUSSION: An upper-level trough will move through the region today. Expect a considerably cooler day today with temperatures around 15 degrees lower than yesterday. Marine cloud cover will slowly break up to partly to mostly cloudy skies this afternoon. Air mass will be generally unstable today with considerably cooler air aloft from the upper trough. Current satellite picture shows still considerable cloud cover over the Willamette Valley but thinning and breaking up of the clouds is beginning. Pressure gradients are still stacked toward the Cascades with 5.7 mb difference between Salem to Redmond while only 1.2 mb difference between Newport and Salem. This should slowly equalize this afternoon and evening but probably remain stacked toward the Cascades. TODAY'S FORECAST: Salem's high temperature today will be near 74. Minimum relative humidity 51%. Surface winds: SW 3-6 mph during the morning becoming SW to WNW at 5-9 mph this afternoon. Transport winds: SW at 4-7 mph during the morning becoming W to NW at 6-10 mph during the afternoon. Mixing height: Rising to 4000 ft by noon and up to 5000 ft during the afternoon. Sunset tonight: 8:47 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 71 74 68 Relative Humidity: 57% 51% 63% Surface Wind Direction: 230 280 290 Surface Wind Speed: 5 7 8 Transport Wind Direction: 280 300 320 Transport Wind Speed: 6 8 10 Estimated Mixing Height: 4500 5000 2500 Ventilation Index: 27 40 25 EXTENDED DISCUSSION: Upper level trough will move by to the east of the state tonight as it weakens. Expect gradual warming. A minor ridge tries to move in on Wednesday but flattens as it does, leaving the region under westerly flow aloft. Temperatures gradually return to seasonal normals. Wind flow turns northerly through the remainder of the week with slight onshore flow during the later afternoon. However, it appears it won't be enough to make for good burning conditions. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 29184 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Jul 26 08:39:48 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 26 Jul 2011 08:39:48 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:40 AM PDT TUES JUL 26 2011 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from 11:00am to 2:00pm with a 50 acre limit. Propane flaming is allowed from 11:00am to 5:00pm. WEATHER DISCUSSION: Upper level trough from yesterday has weakened and moved off to the east. The current upper level pattern is a weak trough with generally zonal flow overhead. Expect a tranquil day with skies partly to mostly cloudy under residual marine air. Air mass is somewhat stable this morning but will destabilize by the late morning to early afternoon. Expect generally light northerly flow. This morning's sounding shows a fairly moist marine layer to 3500 ft. However, it is not as moist as yesterday, so expect clearing to come earlier today. Wind flow has already turned northerly and should remain so with only a slight turning to NNW during the afternoon. Pressure gradients are light with equal gradient stacking from the Coast Range to the Cascades. TODAY'S FORECAST: Salem's high temperature today will be near 75. Relative humidity drops to 50% by 2pm. Minimum relative humidity 41%. Surface winds: NW to N at 5-10 mph. Transport winds: Northerly at 8-12 mph. Mixing height: Rising above 3000 ft by 11 am and above 5000 ft by 2 pm. Sunset tonight: 8:46 pm. THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 68 72 75 70 Relative Humidity: 61% 49% 41% 51% Surface Wind Direction: 360 340 340 320 Surface Wind Speed: 6 7 10 11 Transport Wind Direction: 360 350 350 360 Transport Wind Speed: 8 9 10 12 Estimated Mixing Height: 3300 5000 5000+ 4500 Ventilation Index: 26 45 50 54 EXTENDED DISCUSSION: Little change in the weather pattern expected for the remainder of the week. Look for weak westerly flow with a minor ridge nosing in late Wednesday and Thursday. Wind flow will remain generally northerly with a little more offshore flow likely Thursday and Friday. Temperatures will gradually warm through the week. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 29696 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Jul 26 11:38:03 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 26 Jul 2011 11:38:03 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:40 AM PDT TUES JUL 26 2011 BURN ADVISORY: Agricultural burning is not recommended. 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: Upper level trough from yesterday has weakened and moved off to the east. The current upper level pattern is a weak trough with generally zonal flow overhead. Expect a tranquil day with skies partly to mostly cloudy under residual marine air. Expect generally light northerly flow. Satellite picture shows clouds slowly breaking up and dissipating. Clear skies east of the Cascades are causing pressures to lower and thus creating gradient stacking over the Cascades. Salem to Redmond is 2.4 mb onshore while Newport to Salem is .6 mb onshore. TODAY'S FORECAST: Salem's high temperature today will be near 75. Relative humidity drops to 50% by 2pm. Minimum relative humidity 41%. Surface winds: NW to N at 5-10 mph. Transport winds: Northerly at 8-12 mph. Mixing height: Rising above 5000 ft by 2 pm. Sunset tonight: 8:46 pm. THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 72 75 70 Relative Humidity: 49% 41% 51% Surface Wind Direction: 340 340 320 Surface Wind Speed: 7 10 11 Transport Wind Direction: 350 350 360 Transport Wind Speed: 9 10 12 Estimated Mixing Height: 5000 5000+ 4500 Ventilation Index: 45 50 54 EXTENDED DISCUSSION: Little change in the weather pattern expected for the remainder of the week. Look for weak westerly flow with a minor ridge nosing in late Wednesday and Thursday. Wind flow will remain generally northerly with a little more offshore flow likely Thursday and Friday. Temperatures will gradually warm through the week. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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. Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 29184 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Jul 27 08:48:09 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 27 Jul 2011 08:48:09 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:46 AM PDT WED JUL 27, 2011 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from 10:00 a.m. until 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from 10:00 a.m. until 5:00 p.m. WEATHER DISCUSSION: The Pacific Northwest is still under the influence of a broad upper-level trough, but it is beginning to weaken and push to the east. A minor disturbance rotated across western Oregon early this morning. It brought just some high clouds but helped reinforce the deep marine layer over the Willamette Valley. Salem's sounding this morning showed a couple of degrees of cooling in the marine layer, from the surface to about 5000 feet, with minor warming aloft. Visible satellite imagery showed low clouds covering most of western Oregon, from Coos and Douglas Counties northward The surface map shows high pressure pushing into Washington and northwest Oregon and a thermal trough starting to build northward into southwestern Oregon. That is increasing the northerly pressure-gradients across the Willamette Valley. North winds were already blowing near 10 mph in the northern and central Willamette Valley, at mid-morning, with Eugene getting gusts over 20 mph. Northerly surface and transport winds will slowly increase through this afternoon. As the parent upper-level trough shifts east of the region today, the flow aloft will turn northwesterly and continue to slowly warm. That will help clear the marine clouds from the western valleys, with mostly sunny skies expected this afternoon. The air mass is still cooler than normal, so daytime heating will yield high afternoon mixing heights. TODAY'S FORECAST: Morning clouds with afternoon sunshine. Salem's high temperature today will be near 78 degrees (normal is 83). Relative humidity drops to 60% about 10 a.m. and to near 35% by 5 p.m. Surface winds: N 10 mph; becoming NW 10 mph this evening. Transport winds: N 12 mph this morning; N 12-15 mph this afternoon. Mixing height: Rises to 3000 feet about 10 a.m. and to 5500 feet by 5 p.m. Salem's sunset tonight: 8:44 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 66 74 77 73 Relative Humidity: 56% 42% 36% 43% Surface Wind Direction: 360 360 350 320 Surface Wind Speed: 10 10 10 10 Transport Wind Direction: 360 360 360 340 Transport Wind Speed: 12 12 14 15 Mixing Height: 3500 5000 5500 3000 Ventilation Index: 37 60 77 45 EXTENDED DISCUSSION: Little change in the weather pattern is forecast for Thursday and Friday, with a dry west-northwesterly flow aloft and mostly northerly surface and transport winds. Very slow warming of the air mass will help temperatures recover to near normal (low to mid 80s). The flow aloft will turn southwesterly over the weekend, as a weak upper-level trough moves across British Columbia. Temperatures will likely warm a few more degrees with continued mostly sunny skies. Another system is forecast to take a more southern track and approach the coastline early next week. That may create burning opportunities, as northerly transport winds turn back onshore. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 31744 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Jul 27 11:54:10 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 27 Jul 2011 11:54:10 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:53 AM PDT WED JUL 27, 2011 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from now until 2:00 p.m. with a 50 acre limit. Propane flaming is allowed from now until 5:00 p.m. WEATHER DISCUSSION: A broad upper-level trough is finally pushing east of the region, with a drier northwesterly flow aloft developing over western Oregon. Late-morning visible satellite imagery showed marine clouds breaking up over the Willamette Valley, where temperatures had climbed into the mid to upper 60s. The surface map shows high pressure pushing into Washington and northwest Oregon and a thermal trough building into southwestern Oregon. That is increasing the northerly pressure-gradients across the central and southern Willamette Valley. Late-morning winds were northerly near 10 mph in the Salem area and gusting to more than 20 mph in Eugene. The air mass is still on the cool side, so high temperatures will top out about 5 degrees below normal this afternoon. Northerly winds will aid in the drying of damp fields. TODAY'S FORECAST: Mostly sunny. Salem's high temperature today will be near 78 degrees (normal is 83). Relative humidity drops to near 35% by 5 p.m. Surface winds: N 10-15 mph. Transport winds: N 12-15 mph. Mixing height: Rises to 5500 feet by 5 p.m. Salem's sunset tonight: 8:44 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 73 77 73 Relative Humidity: 43% 36% 45% Surface Wind Direction: 360 360 340 Surface Wind Speed: 10 12 10 Transport Wind Direction: 360 360 340 Transport Wind Speed: 12 14 15 Mixing Height: 5000 5500 3000 Ventilation Index: 60 77 45 EXTENDED DISCUSSION: Little change in the weather pattern is forecast for Thursday and Friday, with a dry west-northwesterly flow aloft and mostly northerly surface and transport winds. Very slow warming aloft will help temperatures recover to near normal (low to mid 80s), while slightly suppressing mixing heights. The flow aloft will turn southwesterly over the weekend, as a weak upper-level trough moves across British Columbia. Temperatures will likely warm a few more degrees with continued mostly sunny skies. Another weak trough is forecast to approach the coastline early next week. Although unlikely to cause an precipitation, it should force the surface thermal trough east of the Cascades and induce onshore flow into the Willamette Valley. That will begin a minor cooling process and could create burning opportunities. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 30720 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 28 08:50:52 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 28 Jul 2011 08:50:52 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT THU JUL 28, 2011 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: The Pacific Northwest is under a dry and stable west-northwesterly flow aloft today. Salem's sounding this morning showed several degrees of warming, compared to 24 hours ago, from the surface to about 10,000 feet with north to northeast winds throughout the layer. Visible satellite imagery showed some patchy marine clouds along the north coast, and in the extreme northern Willamette Valley, with clear skies across the remainder of the state. The surface map shows high pressure pushing into Washington and a weak thermal trough building northward into southwestern Oregon. That will maintain dry north to northeasterly winds over the Willamette Valley today, which should aid in the drying of damp fields. Warmer air aloft will lead to slightly lower mixing heights today, as temperatures return to near normal. TODAY'S FORECAST: Sunny and warmer. Salem's high temperature today will be near 84 degrees (normal is 83). Relative humidity drops to 50% about 11 a.m. and to near 35% by 2 p.m. Surface winds: N 5-10 mph; N 10-15 mph this afternoon. Transport winds: NNE 10-15 mph this morning; NNE 15-20 mph this afternoon. Mixing height: Rises to 3000 feet about noon and to 4000 feet by 2 p.m. Salem's sunset tonight: 8:43 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 70 80 83 77 Relative Humidity: 51% 37% 33% 42% Surface Wind Direction: 360 360 010 360 Surface Wind Speed: 7 10 13 12 Transport Wind Direction: 015 010 015 010 Transport Wind Speed: 13 16 18 20 Mixing Height: 2800 4000 4300 2800 Ventilation Index: 36 64 77 56 EXTENDED DISCUSSION: A weak system cutting across British Columbia will turn the flow aloft slightly more westerly on Friday, but surface and transport winds should remain generally northerly with little change in temperatures or mixing heights. The flow aloft will turn southwesterly on Saturday, as a stronger upper-level trough moves across British Columbia. Temperatures will likely warm a few degrees with continued mostly sunny skies and northerly low-level winds. By Sunday, an offshore trough will increase the southwesterly flow aloft. Temperatures should be seasonal with patchy morning marine clouds and afternoon sunshine. That general pattern is forecast to continue through much of next week, with afternoon northwesterly transport winds possibly creating favorable burning conditions at times. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 31232 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Jul 28 11:57:07 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 28 Jul 2011 11:57:07 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT THU JUL 28, 2011 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: A dry and stable west-northwesterly flow aloft is finally bringing more typical "summer weather" to the Pacific Northwest. Late-morning visible satellite imagery showed clear skies virtually statewide. The surface map shows high pressure pushing into Washington and northwestern Oregon along with a weak thermal trough building into southwestern Oregon. That is producing north to northeasterly winds across the Willamette Valley, which should aid in the drying of damp fields. Warmer air aloft will lead to slightly lower mixing heights today, as temperatures return to near normal. TODAY'S FORECAST: Sunny and warmer. Salem's high temperature today will be near 84 degrees (normal is 83). Relative humidity drops to near 35% by 2 p.m. Surface winds: NNE 10-15 G20 mph. Transport winds: NNE 15-20 mph. Mixing height: Rises to 4000 feet by 2 p.m. and to near 4500 feet by 5 p.m. Salem's sunset tonight: 8:43 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 80 83 77 Relative Humidity: 37% 33% 42% Surface Wind Direction: 010 015 005 Surface Wind Speed: 12 13 12 Transport Wind Direction: 010 015 010 Transport Wind Speed: 16 18 20 Mixing Height: 4000 4300 2800 Ventilation Index: 64 77 56 EXTENDED DISCUSSION: A weak system cutting across British Columbia will turn the flow aloft slightly more westerly on Friday, with little change in low-level winds, temperatures or mixing heights from today. Weak southwesterly flow aloft is forecast for this weekend, with weather systems staying well to our north, across British Columbia. Northerly low-level winds are forecast to turn more northwesterly next week. That will keep temperatures moderate and could create favorable burning opportunities. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 30208 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 29 09:10:25 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 29 Jul 2011 09:10:25 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:43 AM PDT FRI JUL 29, 2011 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: A weak system cutting across British Columbia has turned the flow aloft more westerly this morning. Salem's morning sounding showed westerly winds above 9000 feet and northwesterly winds from 9000 feet down to about 5000 feet. Below 5000 feet, north to northeasterly winds still prevailed. The surface map shows weak onshore flow across the northwestern corner of Oregon, with the flow turning light northerly from about Marion County southward across the central and southern Willamette Valley. Northerly pressure-gradients are stronger across southwestern Oregon, into a weak thermal trough trying to build northward from California. Visible satellite imagery showed marine clouds had advanced back onto the northern and central coastline. Weak onshore flow had also pushed low clouds up the Columbia River into sections of the extreme northern Willamette Valley. Elsewhere across western Oregon, north to northeasterly low-level winds were keeping skies clear. The weather system moving across British Columbia is too far away to change the wind-flow to onshore across the central and southern Willamette Valley today. North-northeasterly low-level winds are forecast to turn due northerly this afternoon. That should keep skies clear with similar temperatures and mixing heights to yesterday. TODAY'S FORECAST: Sunny and warm. Salem's high temperature today will be near 86 degrees (normal is 83). Relative humidity drops to 50% about 11 a.m. and to near 30% by 5 p.m. Surface winds: NNE 5-10 mph this morning; N 8-12 mph this afternoon. Transport winds: NNE 8-12 mph this morning; N 15 mph this afternoon. Mixing height: Rises to 3000 feet about noon and to 4500 feet by 5 p.m. Salem's sunset tonight: 8:42 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 71 80 85 78 Relative Humidity: 51% 38% 31% 42% Surface Wind Direction: 010 360 360 350 Surface Wind Speed: 6 8 10 10 Transport Wind Direction: 015 360 360 360 Transport Wind Speed: 11 13 15 18 Mixing Height: 2500 4000 4500 2800 Ventilation Index: 28 52 68 50 EXTENDED DISCUSSION: The flow aloft will turn southwesterly over the weekend, as an upper-level trough moves inland and across southern British Columbia. Low-level winds will likely stay northerly across the Willamette Valley with mostly sunny skies and little change in temperatures. Weak onshore flow, at times, next week will keep temperatures near normal and could create some favorable burning opportunities. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast.doc Type: application/msword Size: 31232 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Jul 29 11:49:15 2011 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 29 Jul 2011 11:49:15 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:48 AM PDT FRI JUL 29, 2011 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: A weak system is cutting across British Columbia with a dry westerly flow aloft over Oregon. The late-morning surface map showed weak onshore flow across the northwestern corner of Oregon, with northerly pressure-gradients in the Willamette Valley. Valley winds were mostly northerly near 10 mph. Visible satellite imagery showed patchy marine clouds breaking up along the coast and along the Columbia River into the Portland area. Elsewhere, skies are clear across western Oregon. Temperatures are running about the same as 24 hours ago in the extreme northern Willamette Valley and 3-5 degrees warmer than late-morning yesterday across the central and southern valley. The weather system moving across British Columbia is too far away to force onshore flow into the central and southern Willamette Valley today, so expect northerly winds to prevail. That should keep skies clear with temperatures warming into the mid 80s. TODAY'S FORECAST: Sunny and warm. Salem's high temperature today will be near 86 degrees (normal is 83). Relative humidity drops to near 30% by 5 p.m. Surface winds: N 8-12 mph this afternoon. Transport winds: N 15 mph this afternoon. Mixing height: Rises to 4500 feet by 5 p.m. Salem's sunset tonight: 8:42 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 80 85 78 Relative Humidity: 38% 31% 42% Surface Wind Direction: 360 360 350 Surface Wind Speed: 8 10 10 Transport Wind Direction: 360 360 360 Transport Wind Speed: 13 15 18 Mixing Height: 4000 4500 2800 Ventilation Index: 52 68 50 EXTENDED DISCUSSION: The flow aloft will turn southwesterly over the weekend, as an upper-level trough moves inland and across southern British Columbia. Low-level winds will likely stay northerly across the Willamette Valley with mostly sunny skies and little change in temperatures. Southwesterly flow aloft is forecast to increase just enough next week to induce weak onshore flow at times. That will keep temperatures near normal and could create some favorable burning opportunities. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text 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: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast.doc Type: application/msword Size: 30208 bytes Desc: Silverton Hills Midday Forecast.doc URL: