From willamette-fcst at listsmart.osl.state.or.us Tue Sep 4 08:34:24 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 04 Sep 2012 11:34:24 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 04 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Sep 4 11:46:24 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 04 Sep 2012 14:46:24 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 04 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Sep 4 12:10:31 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 04 Sep 2012 15:10:31 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 04 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Wed Sep 5 08:30:08 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 05 Sep 2012 11:30:08 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Wed, Sep 05 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Thu Sep 6 08:39:52 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 06 Sep 2012 11:39:52 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Thu, Sep 06 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Thu Sep 6 11:46:43 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 06 Sep 2012 14:46:43 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Thu, Sep 06 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Fri Sep 7 08:42:57 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 7 Sep 2012 08:42:57 -0700 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:40 AM PDT FRI SEP 07 2012 BURN ADVISORY: Agricultural burning burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: Upper level ridge continues to build over the state today with a minor low pressure area to the southwest in the eastern Pacific. Expect mostly sunny skies. Satellite picture currently shows clear skies over the interior of the state with some low clouds and fog along the coast. These clouds will dissipate during the morning to early afternoon. This morning's sounding showed a strong surface temperature inversion very typical for a summertime ridge pattern. Low-level winds were northerly to 2000 ft, turning easterly from 2000 - 5000 ft. Expect mixing to remain poor throughout the morning with the heating of the day taking awhile to allow mixing to lift up to fair levels during the afternoon. Transport winds will be light but favoring N to NE, then turning NW'erly this evening. Surface pressure pattern shows the thermal trough along the western side of the Willamette Valley. Current pressure gradients are .5 mb onshore from Newport to Salem and 5.3 mb offshore from Salem to Redmond. The thermal trough will remain in the Willamette Valley throughout the day with increasing onshore flow over the Coast Range with offshore flow remaining but weakening over the Cascades. TODAY'S FORECAST: Sunny. Salem's high temperature today will be near 91. Relative humidity drops to 50% near 11 a.m. Minimum relative humidity 25%. Surface winds: Mostly northerly at 4-7 mph, turning NW'erly during the evening. Transport winds: N to NE at 5-8 mph, turning NW'erly during the evening. Maximum mixing height: near 4000 ft. Sunset tonight: 7:36 pm THREE-HOURLY DATA: 11am 2pm 5pm 8pm Temperature: 73 85 91 80 Relative Humidity: 51% 32% 24% 35% Surface Wind Direction: 010 360 360 320 Surface Wind Speed: 6 7 7 5 Transport Wind Direction: 360 020 030 310 Transport Wind Speed: 5 7 6 6 Estimated Mixing Height: 1000 2500 3800 1500 Ventilation Index: 5 18 23 9 EXTENDED DISCUSSION: Upper level ridge will shift eastward on Saturday as the upper low in the eastern Pacific develops into a trough and starts moving inland over the weekend. This will bring some cooling over the region tomorrow and a chance of thunderstorms over the Cascades. Pressure pattern turns onshore. Skies, however, should remain mostly clear in the Willamette Valley. The trough will strengthen and move inland on Sunday bringing further cooling as marine low clouds move into the Valley. Another trough will drop down from the northwest Sunday evening and may produce some light rain over the region early Monday. This trough will quickly move to the east late Monday and Tuesday with another upper ridge moving in for the middle of next 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: 31232 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Sep 7 11:44:22 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 7 Sep 2012 11:44:22 -0700 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT FRI SEP 07 2012 BURN ADVISORY: Agricultural burning burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: Upper level ridge continues to build over the state today with a minor low pressure area to the southwest in the eastern Pacific. Expect mostly sunny skies. Expect mixing to slowly improve this afternoon with the heating of the day. Maximum mixing rises to about 4000 ft. Transport winds will be light N to NE, and then turn NW'erly this evening. Surface pressure pattern shows the thermal trough along the western side of the Willamette Valley extending to the northern Oregon coast. Current pressure gradients are .8 mb onshore from Newport to Salem and 4.5 mb offshore from Salem to Redmond. The thermal trough will remain in the Willamette Valley throughout the day with increasing onshore flow over the Coast Range with offshore flow remaining but weakening over the Cascades. TODAY'S FORECAST: Sunny Salem's high temperature today will be near 93. Relative humidity: Minimum relative humidity 22%. Surface winds: Mostly northerly at 4-7 mph, turning NW'erly during the evening. Transport winds: N to NE at 5-8 mph, turning NW'erly during the evening. Maximum mixing height: near 4000 ft. Sunset tonight: 7:36 pm THREE-HOURLY DATA: 2pm 5pm 8pm Temperature: 85 93 81 Relative Humidity: 30% 22% 35% Surface Wind Direction: 360 360 320 Surface Wind Speed: 7 7 5 Transport Wind Direction: 020 030 310 Transport Wind Speed: 7 6 6 Estimated Mixing Height: 2700 4000 1500 Ventilation Index: 18 23 9 EXTENDED DISCUSSION: Upper level ridge will shift eastward on Saturday as the upper low in the eastern Pacific develops into a trough and starts moving inland over the weekend. This will bring some cooling over the region tomorrow and a chance of thunderstorms over the Cascades. Pressure pattern turns onshore. Skies, however, should remain mostly clear in the Willamette Valley. The trough will strengthen and move inland on Sunday bringing further cooling as marine low clouds move into the Valley. Another trough will drop down from the northwest Sunday evening and may produce some light rain over the region early Monday. This trough will quickly move to the east late Monday and Tuesday with another upper ridge moving in for the middle of next 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: 31232 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Sep 10 08:32:11 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 10 Sep 2012 11:32:11 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Mon, Sep 10 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Sep 11 08:45:43 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 11 Sep 2012 11:45:43 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 11 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Sep 11 09:07:12 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 11 Sep 2012 12:07:12 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 11 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Sep 11 11:47:10 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 11 Sep 2012 14:47:10 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 11 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Wed Sep 12 08:48:15 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 12 Sep 2012 08:48:15 -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 SEP 12, 2012 BURN ADVISORY: ...Fire Marshal conditions may be reached this afternoon... (relative humidity is expected to drop well below 30% and wind speeds may increase to at or above 15 mph) Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: An upper-level ridge is building over the Pacific Northwest. At the surface, a thermal trough is building northward along the southern Oregon Coast, with increasing offshore flow across western Oregon. The Salem sounding this morning showed considerable warming aloft, compared to 24 hours ago, with brisk northeasterly winds from just above the surface up to about 6000 feet. Satellite imagery shows clear skies over all of Washington and Oregon, with the exception of areas of wildfire smoke. Some elevated smoke from the wildfire near Sisters, Oregon appeared to be streaming westward over the southern Willamette Valley. Some smoke from wildfires in south-central Washington may get transported across northwestern Oregon this afternoon. Warmer air aloft will suppress mixing heights today. In addition, increasing northeasterly winds and very low relative humidity will make for unfavorable burning conditions this afternoon. (Salem Airport data for Tuesday, Sept. 11th: High 74?F; Rainfall .00") TODAY'S FORECAST: Sunny and warmer. Turning breezy and possibly a little hazy this afternoon. Salem's high temperature today will be near 84 degrees (normal is 78). Relative humidity drops well below 30% this afternoon. Surface winds: N 5-12 mph; becoming NE 10-15 mph this afternoon. Transport winds: NE 12-18 mph. Mixing height: Rising to 2000 feet by noon and to near 3000 feet by 5 p.m. Salem's sunset tonight: 7:27 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 64 76 82 72 Relative Humidity: 43% 25% 19% 29% Surface Wind Dir/Speed: N 10 NE 12 NE 15 NE 8 Transport Wind Dir/Speed: NE 15 NE 15 NE 18 NE 12 Mixing Height: 1800 2500 3200 1500 Ventilation Index: 27 38 58 18 EXTENDED DISCUSSION: The center of the broad upper-level ridge is forecast to shift over Idaho on Thursday, with a strong surface thermal trough remaining over western Oregon. Valley temperatures will likely climb into the low 90s with slackening northeasterly transport winds. The thermal trough will likely shift into eastern Oregon on Friday, as a weak upper-level trough turns the flow aloft southwesterly. That should create more favorable burning conditions, as the transport winds turn onshore and cooling aloft improves mixing. Valley temperatures will cool back into the mid 80s. The dry upper-level trough is forecast to move across Oregon on Saturday, with increasing onshore flow likely bringing some morning marine clouds into the valley and helping to cool high temperatures back to near normal. The flow aloft is forecast to turn more northerly on Sunday, which appears to be the beginning of another period of quite warm and continued dry weather. Sunny skies and offshore flow is forecast for much of next week, which would be unfavorable for burning. 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 Sep 12 11:28:53 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 12 Sep 2012 11:28:53 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:30 AM PDT WED SEP 12, 2012 BURN ADVISORY: ...Fire Marshal conditions may be reached this afternoon... (relative humidity is expected to drop well below 30% and wind speeds may increase to at or above 15 mph) Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: An upper-level ridge is strengthening over the Pacific Northwest, with a surface thermal trough building northward along the southern Oregon Coast. Offshore flow is bringing sunny skies to the entire state today, along with warmer temperatures. Some haze, from area wildfires, is possible across northwestern Oregon this afternoon. Warmer air aloft will suppress mixing heights today. In addition, brisk northeasterly winds and very low relative humidity will make for unfavorable burning conditions this afternoon. TODAY'S FORECAST: Sunny, warmer, and breezy. Possibly turning hazy. Salem's high temperature today will be near 84 degrees (normal is 78). Relative humidity will drop well below 30% this afternoon. Surface winds: NE 10-15 mph. Transport winds: NE 15-25 mph. Mixing height: Slowly climing to near 3000 feet by 5 p.m. Salem's sunset tonight: 7:27 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 76 82 72 Relative Humidity: 25% 19% 29% Surface Wind Dir/Speed: NE 12 NE 15 NE 10 Transport Wind Dir/Speed: NE 15 NE 20 NE 15 Mixing Height: 2500 3200 1500 Ventilation Index: 38 64 23 EXTENDED DISCUSSION: The center of a broad upper-level ridge of high pressure is forecast to shift over Idaho on Thursday, with a strong surface thermal trough likely remaining over western Oregon. Look for valley temperatures to climb into the low 90s with slackening northeasterly transport winds. The thermal trough is forecast to shift into eastern Oregon on Friday, as a weak upper-level trough turns the flow aloft southwesterly. That may create more favorable burning conditions, as the transport winds turn onshore and cooling aloft improves mixing. Valley temperatures should cool back into the mid 80s. The dry upper-level trough is forecast to move across Oregon on Saturday, with increasing onshore flow likely bringing some morning marine clouds into the valley and helping to cool high temperatures back to near normal. The flow aloft is forecast to turn more northerly on Sunday, which appears to be the beginning of another period of quite warm and continued dry weather. A return to offshore flow is forecast for much of next week, which would be unfavorable for burning. 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 Thu Sep 13 08:57:03 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 13 Sep 2012 08:57:03 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT THU SEP 13, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: A broad upper-level ridge of high pressure remains over the Pacific Northwest this morning. At the surface, a thermal trough extends northward along the Oregon Coast, with continued offshore flow across western Oregon. The Salem sounding this morning was not available, but ODF SODAR, located in the central coast range, showed easterly winds from near the surface up through 3500 feet. Satellite imagery shows mostly clear skies across the state, except for low clouds banked up along the southern coast. Yesterday's offshore flow transported smoke, from wildfires in the Cascades and central Oregon, into northwestern Oregon. DEQ air quality monitors are showing elevated smoke levels across all of northwestern Oregon this morning. The axis of the upper-level ridge is forecast to slowly progress eastward, to over Idaho, this afternoon with a weak southwesterly flow aloft over Oregon. The surface thermal trough will shift from the coast into the Willamette Valley. That will return onshore flow to the immediate coastline, with winds in the valley becoming light and variable. The combination of light winds and very warm air aloft will make for poor ventilation conditions today. (Salem Airport data for Wednesday, Sept. 12th: High 87?F; Rainfall .00") TODAY'S FORECAST: Sunny, hazy, and very warm. Salem's high temperature today will be near 92 degrees (normal is 78). Relative humidity drops below 30% by noon. Surface winds: N-NE near 5 mph. Transport winds: NE 5 mph; becoming light and variable this afternoon. Mixing height: Only rising to near 2500 feet this afternoon. Salem's sunset tonight: 7:25 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 69 84 88 74 Relative Humidity: 31% 19% 16% 28% Surface Wind Dir/Speed: N 5 NE 5 N 5 N 3 Transport Wind Dir/Speed: NE 5 VAR 5 Var 5 Var 3 Mixing Height: 1200 2000 2500 1000 Ventilation Index: 6 10 13 3 EXTENDED DISCUSSION: The upper-level ridge is forecast to weaken on Friday, with the thermal trough shifting into eastern Oregon. Increasing southwesterly flow aloft and onshore transport winds may create favorable burning conditions Friday afternoon and help to clear wildfire smoke from the valley. Cooler onshore flow will likely cap high temperatures in the mid 80s. A very weak and dry upper-level trough is forecast to move across Oregon on Saturday. Skies should remain mostly sunny, but onshore flow may be just strong enough to bring some morning marine clouds into the valley. Temperatures should cool back close to normal. The flow aloft is forecast to turn more northerly on Sunday, with temperatures beginning to warm again. A strong upper-level ridge is forecast to return next week; bringing another round of offshore flow and very warm weather. Air quality is likely to deteriorate, as wildfire smoke gets transported back across northwestern Oregon. The chances for burning opportunities next week look slim. 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: 32256 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Sep 13 11:56:18 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 13 Sep 2012 11:56:18 -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 THU SEP 13, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: A broad upper-level ridge of high pressure remains over the Pacific Northwest this morning. Its axis is slowly shifting east, to over Idaho, with increasing southwesterly flow aloft over Oregon. At the surface, a strong thermal trough extends northward along the Oregon Coast. Low-level winds are still offshore across the interior of western Oregon and the north coast but have turned onshore along the central and south coast. Satellite imagery shows mostly clear skies across the state, with marine low clouds advancing northward along the south coast. The offshore flow has transported smoke, from wildfires in the Cascades, across NW Oregon. DEQ air quality monitors are showing elevated smoke levels across western Oregon, as far south as Roseburg. The surface thermal trough is forecast to slowly drift from the coast into the Willamette Valley this afternoon. Onshore flow will continue to spread northward up the coast, with winds in the valley becoming light and variable. The combination of light winds and very warm air aloft will make for poor ventilation conditions this afternoon. TODAY'S FORECAST: Sunny, hazy, and very warm. Salem's high temperature today will be near 92 degrees (normal is 78). Relative humidity drops to below 20% this afternoon. Surface winds: N-NE near 5 mph. Transport winds: NE 5 mph; becoming light and variable this afternoon. Mixing height: Only rising to near 2500 feet this afternoon. Salem's sunset tonight: 7:25 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 84 88 74 Relative Humidity: 19% 16% 28% Surface Wind Dir/Speed: NE 5 N 5 N 3 Transport Wind Dir/Speed: VAR 5 Var 5 Var 3 Mixing Height: 2000 2500 1000 Ventilation Index: 10 13 3 EXTENDED DISCUSSION: The upper-level ridge is forecast to weaken on Friday, with the thermal trough shifting into eastern Oregon. Increasing southwesterly flow aloft and onshore transport winds will likely create favorable burning conditions Friday afternoon and help to clear wildfire smoke from the valley. Cooler onshore flow should cap high temperatures in the mid 80s. A very weak and dry upper-level trough is forecast to move across Oregon on Saturday. Skies should remain mostly sunny, but onshore flow may be just strong enough to bring some morning marine clouds into the valley. Temperatures should cool back close to 80?F. The flow aloft is forecast to turn more northerly on Sunday, with temperatures beginning to warm again. A strong upper-level ridge is forecast to return next week; bringing another round of offshore flow and very warm weather. Air quality is likely to deteriorate, as wildfire smoke gets transported back across northwestern Oregon. The chances for burning opportunities next week look slim. 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: 32256 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Sep 14 08:58:15 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 14 Sep 2012 08:58:15 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT FRI SEP 14, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: A broad upper-level ridge of high pressure remains over the Pacific Northwest but is weakening and shifting eastward this morning. A surface thermal trough extends across the interior of western Oregon. Low-level winds have turned onshore along the immediate coastline and light in the Willamette Valley. The Salem sounding this morning showed very warm air aloft with a strong surface-based inversion extending up about 1800 feet. Winds above the inversion were southwesterly. Satellite imagery shows partly cloudy skies across most of the state, with a solid deck of low clouds and fog banked up along the entire coastline. Yesterday's offshore flow transported smoke, from wildfires in the Cascades, into northwestern Oregon. DEQ air quality monitors are still showing somewhat elevated smoke levels across all of northwestern Oregon this morning. The upper-level ridge will continue to slide eastward and weaken today, in response to an approaching very weak upper-level trough. Increasing southwesterly flow aloft should force the surface thermal trough east of the Cascades later this afternoon. Only minor cooling aloft is expected, so mixing heights will be slow to climb above 3000 feet. In addition, the westerly wind push forecast by the computer models is weak. That said, conditions will likely be favorable for some open burning this afternoon. The westerly transport flow should also help to clear wildfire smoke from the valley. High temperatures will likely get capped in the mid 80s. (Salem Airport data for Thursday, Sept. 13th: High 91?F; Rainfall .00") TODAY'S FORECAST: Mostly sunny and a little cooler. Salem's high temperature today will be near 86 degrees (normal is 78). Relative humidity drops below 50% by noon and to near 30% by 5 p.m. Surface winds: Light and variable; turning light NW this evening. Transport winds: Becoming W 7-10 mph this afternoon. Mixing height: Rising to 3000 feet by 3 p.m. and to near 3500 feet by 5 p.m. Salem's sunset tonight: 7:24 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 72 81 84 71 Relative Humidity: 44% 34% 31% 51% Surface Wind Dir/Speed: VAR 3 VAR 3 NW 3 NW 5 Transport Wind Dir/Speed: VAR 3 W 7 W 9 W 8 Mixing Height: 1200 2500 3500 1500 Ventilation Index: 7 18 32 12 EXTENDED DISCUSSION: A very weak and dry upper-level trough is forecast to move across Oregon on Saturday. Skies should remain mostly sunny, but onshore flow may be just strong enough to bring some morning marine clouds into the valley. Temperatures should cool back close to 80?F. The flow aloft is forecast to turn more northerly on Sunday, with temperatures beginning to warm again. A strong upper-level ridge is forecast to return next week; bringing another round of offshore flow and very warm weather. Air quality is likely to deteriorate, as wildfire smoke gets transported back across northwestern Oregon. The chances for burning opportunities next week look slim. 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 Fri Sep 14 11:58:06 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 14 Sep 2012 11:58:06 -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 SEP 14, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: The axis of a broad upper-level ridge of high pressure has shifting eastward, to over the Rockies. The corresponding surface thermal trough is also expected to shift eastward but was still over the interior of western Oregon late this morning. Satellite imagery shows sunny skies west of the Cascades, except for a solid deck of low clouds and fog banked up along the coastline. DEQ air quality monitors are still showing elevated particulate levels, due to wildfire smoke, across all of northwestern Oregon. An approaching very weak upper-level trough will increase the southwesterly flow aloft over Oregon this afternoon. A strong low-level inversion made for poor ventilation conditions this morning, but minor cooling aloft and daytime heating should combine to lift mixing heights to near 4000 feet by late this afternoon. Favorable burning conditions should develop later this afternoon, once the thermal trough moves east of the Willamette Valley. Increasing onshore flow will also help to clear wildfire smoke from the valley. Pibals are scheduled to begin shortly. TODAY'S FORECAST: Mostly sunny and a little cooler. Salem's high temperature today will be near 86 degrees (normal is 78). Relative humidity drops to near 30% by 5 p.m. Surface winds: Light and variable; turning light NW this evening. Transport winds: Becoming W 7-10 mph this afternoon. Mixing height: Rising to 3000 feet by 3 p.m. and to near 4000 feet by 5 p.m. Salem's sunset tonight: 7:24 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 81 84 71 Relative Humidity: 34% 31% 51% Surface Wind Dir/Speed: VAR 3 NW 3 NW 5 Transport Wind Dir/Speed: W 7 W 9 W 8 Mixing Height: 2800 4000 1500 Ventilation Index: 20 36 12 EXTENDED DISCUSSION: A very weak and dry upper-level trough is forecast to move across Oregon on Saturday. Skies should remain mostly sunny, but onshore flow may be just strong enough to bring some morning marine clouds into the valley. Temperatures should cool back close to 80?F. The flow aloft, and at transport level, is forecast to turn northerly on Sunday. A strong upper-level ridge is forecast to return next week; bringing another round of offshore flow and very warm weather. Air quality may deteriorate, with the potential for wildfire smoke to get directed back over western Oregon. The chances for burning opportunities next week look slim. 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: 31232 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Sep 17 11:50:48 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 17 Sep 2012 14:50:48 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Mon, Sep 17 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Sep 18 08:36:06 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 18 Sep 2012 11:36:06 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 18 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Wed Sep 19 08:35:22 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 19 Sep 2012 11:35:22 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Wed, Sep 19 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Wed Sep 19 08:37:29 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 19 Sep 2012 11:37:29 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Wed, Sep 19 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Wed Sep 19 11:37:28 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 19 Sep 2012 14:37:28 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Wed, Sep 19 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Thu Sep 20 08:57:12 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 20 Sep 2012 08:57:12 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT THU SEP 20, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: A strong upper-level ridge of high pressure remains over the Pacific Northwest but is shifting eastward this morning in response to a weak trough approaching the Oregon coast. The surface thermal trough has also shifted east, to over the Cascades, which has turned pressure gradients weakly onshore into the Willamette Valley. Visible satellite imagery shows marine low clouds extending from the coast to near the crest of the Cascades and as far south as Roseburg. Surface and area pilot reports indicate that the marine low clouds are about 2000 feet thick. They will likely begin to break up around midday. The Salem sounding this morning showed very warm air aloft, with a strong surface-based inversion extending up about 5000 feet. Smoke levels remain elevated across northwestern Oregon this morning from area wildfires. The upper-level ridge will continue to slide eastward today with increasing southerly flow aloft. The surface thermal trough will likely progress no farther east than central Oregon this afternoon. With very warm air aloft, mixing heights will struggle to reach 3000 feet this afternoon. Even though the low-level flow is onshore, winds at the top of the mixing layer are forecast to be southerly or southeasterly this afternoon, which is not a favorable direction for open burning. In addition, there may not be enough mid-level onshore flow to evacuate existing wildfire smoke from the Cascades. (Salem Airport data for Wednesday, Sept. 19th: High 77?F; Rainfall .00") TODAY'S FORECAST: Morning clouds; mostly sunny in the afternoon. Salem's high temperature today will be near 76 degrees (normal is 76). Relative humidity drops to near 50% from 2 p.m. until 5 p.m. Surface winds: Light and variable; turning NW 5-10 mph late this afternoon. Transport winds: Light and variable; Becoming S 7-12 mph this afternoon. Mixing height: Rising to 2000 feet at noon and to near 3000 feet by 5 p.m. Salem's sunset tonight: 7:12 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 63 72 75 67 Relative Humidity: 65% 51% 49% 63% Surface Wind Dir/Speed: VAR 5 VAR 5 NW 5 NW 8 Transport Wind Dir/Speed: VAR 5 S 7 S 9 NW 10 Mixing Height: 1600 2500 3000 1500 Ventilation Index: 8 18 27 15 EXTENDED DISCUSSION: A weak upper-level trough is forecast to approach the Oregon Coast on Friday; further increasing the southerly flow aloft. That will introduce a chance of afternoon and evening showers or thunderstorms over the Cascades and possibly even over the Willamette Valley. Winds at the top of the mixing layer are forecast to remain southerly or southeasterly. The upper-level trough is forecast to come onshore Saturday; deepening the marine layer over western Oregon for further cooling. There is also a chance of morning drizzle or light showers. The trough is forecast to stall over Oregon and slowly weaken on Sunday. That will maintain a slight chance of showers and slightly below normal 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 AM Forecast.doc Type: application/msword Size: 32256 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Sep 20 11:57:13 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 20 Sep 2012 11:57:13 -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 THU SEP 20, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: Late-morning visible satellite imagery showed marine low clouds still covering most areas west of the Cascade crest. Some breaks in the clouds were showing up over the coast range. Pressure gradients are weakly onshore with appropriate stacking to maintain lift. However, very warm air aloft will keep mixing heights below 3000 feet until surface temperatures warm into the mid 70s. That is not likely until the late afternoon. Smoke levels remain somewhat elevated across northwestern Oregon from area wildfires. The upper-level ridge will continue to slide eastward today with increasing southerly flow aloft. The surface thermal trough will likely progress no farther east than central Oregon this afternoon. Even though the low-level flow is onshore, winds at the top of the mixing layer are forecast to be southerly this afternoon, which is not a favorable direction for open burning. In addition, there may not be enough mid-level onshore flow to evacuate existing wildfire smoke from the valley and the Cascades. TODAY'S FORECAST: Slowly clearing skies this afternoon. Salem's high temperature today will be near 76 degrees (normal is 76). Relative humidity drops to near 50% from 2 p.m. until 5 p.m. Surface winds: Light and variable; turning WNW 5-10 mph late this afternoon. Transport winds: Light and variable; Becoming S 7-12 mph this afternoon. Mixing height: Rising to near 3000 feet by 5 p.m. Salem's sunset tonight: 7:12 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 72 75 67 Relative Humidity: 51% 49% 63% Surface Wind Dir/Speed: VAR 5 NW 5 NW 8 Transport Wind Dir/Speed: S 7 S 9 NW 10 Mixing Height: 2500 3000 1500 Ventilation Index: 18 27 15 EXTENDED DISCUSSION: A weak upper-level trough is forecast to approach the Oregon Coast on Friday; further increasing the southerly flow aloft. That will introduce a chance of afternoon and evening showers or thunderstorms over the Cascades and possibly over the Willamette Valley. Low-level winds will be from the NNW, but winds at the top of the mixing layer are forecast to remain southerly. The upper-level trough is forecast to come onshore Saturday and stall over the state on Sunday; deepening the marine layer over western Oregon for further cooling. There is also a chance of morning drizzle or 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. 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: 32256 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Sep 21 08:56:50 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 21 Sep 2012 08:56:50 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT FRI SEP 21, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: The strong upper-level ridge of high pressure that brought dry and very warm weather to the region for most of the month has shifting eastward, to over the Rockies. A weak offshore upper-level trough is producing southerly flow aloft over Oregon and enhanced the low-level marine layer overnight. The Salem sounding this morning and local pilot reports indicate that the marine layer has deepened to about 4000 feet thick. Areas of drizzle or very light rain are more widespread than yesterday morning, with some spotty reports of measurable rain in the Cascade foothills. Visible satellite imagery shows marine low clouds blanketing all of northwestern Oregon. Unlike yesterday, the low clouds are thick enough to cover the coast range. As is typically the case, the "marine push" has resulted in unfavorable pressure gradient stacking this morning, which is unlikely to reverse this afternoon. One benefit of the increased onshore flow is that the air quality has improved across northwestern Oregon, although there is still some evidence of residual wildfire smoke in the northern Willamette Valley. The upper-level ridge will continue to slowly slide eastward today with the approaching upper-level trough maintaining strong onshore flow into western Oregon. That should keep skies cloudy most of the day, with only some partial clearing possible late this afternoon. High temperatures will likely stay in the 60s (well below normal). The chances for open burning are slim. (Salem Airport data for Thursday, Sept. 20th: High 70?F; Rainfall .00") TODAY'S FORECAST: Morning clouds; mostly sunny in the afternoon. Salem's high temperature today will be near 67 degrees (normal is 76). Relative humidity drops to near 60% by 5 p.m. Surface winds: Light and variable; becoming NW 3-8 mph late this afternoon. Transport winds: Light and variable; Becoming N-NW 5-10 mph this afternoon. Mixing height: Rising to near 3000 feet by 5 p.m. Salem's sunset tonight: 7:10 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 57 62 67 61 Relative Humidity: 90% 75% 63% 78% Surface Wind Dir/Speed: VAR 3 NW 4 NW 5 NW 5 Transport Wind Dir/Speed: VAR 3 NW 4 NW 5 NW 7 Mixing Height: 1500 2500 3000 2000 Ventilation Index: 5 10 15 14 EXTENDED DISCUSSION: A weak upper-level trough is forecast to come onshore tonight and Saturday. That may squeeze some light showers out of the marine deck over the Willamette Valley, but rainfall totals should be less than one-tenth of an inch. Ventilation conditions will improve, but transport winds are forecast to be northerly. Some thunderstorms are likely from the Cascades eastward, with a high potential of starting new wildfires. The upper-level trough is forecast to stall over the state on Sunday. That will maintain a deep marine layer over western Oregon. Skies should remain mostly cloudy with areas of morning drizzle. Unfavorable gradient stacking should continue with northerly transport winds. The upper-level trough is forecast to move east of the state on Monday, with weak westerly flow aloft possibly creating more favorable 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. 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: 32256 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Sep 21 09:00:31 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 21 Sep 2012 09:00:31 -0700 Subject: [willamette-fcst] Corrected Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT FRI SEP 21, 2012 ...Corrected "Today's Forecast"... BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: The strong upper-level ridge of high pressure that brought dry and very warm weather to the region for most of the month has shifting eastward, to over the Rockies. A weak offshore upper-level trough is producing southerly flow aloft over Oregon and enhanced the low-level marine layer overnight. The Salem sounding this morning and local pilot reports indicate that the marine layer has deepened to about 4000 feet thick. Areas of drizzle or very light rain are more widespread than yesterday morning, with some spotty reports of measurable rain in the Cascade foothills. Visible satellite imagery shows marine low clouds blanketing all of northwestern Oregon. Unlike yesterday, the low clouds are thick enough to cover the coast range. As is typically the case, the "marine push" has resulted in unfavorable pressure gradient stacking this morning, which is unlikely to reverse this afternoon. One benefit of the increased onshore flow is that the air quality has improved across northwestern Oregon, although there is still some evidence of residual wildfire smoke in the northern Willamette Valley. The upper-level ridge will continue to slowly slide eastward today with the approaching upper-level trough maintaining strong onshore flow into western Oregon. That should keep skies cloudy most of the day, with only some partial clearing possible late this afternoon. High temperatures will likely stay in the 60s (well below normal). The chances for open burning are slim. (Salem Airport data for Thursday, Sept. 20th: High 70?F; Rainfall .00") TODAY'S FORECAST: Cloudy with areas of drizzle this morning; partial clearing possible late this afternoon. Salem's high temperature today will be near 67 degrees (normal is 76). Relative humidity drops to near 60% by 5 p.m. Surface winds: Light and variable; becoming NW 3-8 mph late this afternoon. Transport winds: Light and variable; Becoming N-NW 5-10 mph this afternoon. Mixing height: Rising to near 3000 feet by 5 p.m. Salem's sunset tonight: 7:10 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 57 62 67 61 Relative Humidity: 90% 75% 63% 78% Surface Wind Dir/Speed: VAR 3 NW 4 NW 5 NW 5 Transport Wind Dir/Speed: VAR 3 NW 4 NW 5 NW 7 Mixing Height: 1500 2500 3000 2000 Ventilation Index: 5 10 15 14 EXTENDED DISCUSSION: A weak upper-level trough is forecast to come onshore tonight and Saturday. That may squeeze some light showers out of the marine deck over the Willamette Valley, but rainfall totals should be less than one-tenth of an inch. Ventilation conditions will improve, but transport winds are forecast to be northerly. Some thunderstorms are likely from the Cascades eastward, with a high potential of starting new wildfires. The upper-level trough is forecast to stall over the state on Sunday. That will maintain a deep marine layer over western Oregon. Skies should remain mostly cloudy with areas of morning drizzle. Unfavorable gradient stacking should continue with northerly transport winds. The upper-level trough is forecast to move east of the state on Monday, with weak westerly flow aloft possibly creating more favorable 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. 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: 32256 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Sep 21 11:56:22 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 21 Sep 2012 11:56:22 -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 SEP 21, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: A weak offshore upper-level trough is slowly approaching the coastline and is producing southerly flow aloft over Oregon. Pilot reports indicate that the solid deck of marine clouds covering all of northwestern Oregon is about 4000 feet thick. Areas of drizzle continued into the late morning across the northern and central Willamette Valley. As of 11 a.m., the Salem Airport had received just a trace of rain, but there have been reports of up to a few hundredths of an inch to the east of Salem, in the Cascades foothills. As is typically the case with a "marine push," pressure gradient stacking is highly unfavorable for burning today. One benefit of the increased onshore flow is an improvement in air quality west of the Cascades. However, the southerly flow aloft is maintaining significant levels of wildfire smoke over the Cascades and across central Oregon, especially in and near Sisters, OR. The approaching upper-level trough should keep skies cloudy today over the northern and central Willamette Valley, along with areas of drizzle. High temperatures will likely stay in the mid 60s (well below normal). As the trough moves onshore tonight, it could also produce areas of light rain. Additional rainfall totals should not exceed a few hundredths of an inch. TODAY'S FORECAST: Cloudy and cool with areas of drizzle. Rainfall totals ranging from a trace to a few hundredths of an inch. Salem's high temperature today will be near 65 degrees (normal is 76). Relative humidity: Likely staying above 65% all day. Surface winds: Light and variable; becoming NW 3-8 mph late this afternoon. Transport winds: Light and variable; Becoming N-NW 5-10 mph this afternoon. Mixing height: Rising to near 3000 feet by 5 p.m. Salem's sunset tonight: 7:10 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 61 64 59 Relative Humidity: 81% 73% 87% Surface Wind Dir/Speed: VAR 4 NW 5 NW 5 Transport Wind Dir/Speed: VAR 4 NW 5 NW 5 Mixing Height: 2500 3000 2000 Ventilation Index: 10 15 10 EXTENDED DISCUSSION: A weak upper-level trough will park over NW Oregon on Saturday. Expect mostly cloudy and cool conditions to continue with areas of drizzle or light showers. Rainfall totals should be less than one-tenth of an inch. Ventilation conditions will improve. However, gradient stacking will likely be unfavorable for burning and transport winds are forecast to be mostly northerly. Some thunderstorms are likely from the Cascades eastward, with a high potential for ignition of new wildfires. The upper-level trough is forecast to slowly drift to over south-central Oregon on Sunday. That will maintain a deep marine layer over western Oregon. Skies should remain mostly cloudy with areas of morning drizzle. Unfavorable gradient stacking should continue with northerly transport winds. The upper-level trough is forecast to move east of the state on Monday. Expect some afternoon clearing with weak westerly flow aloft possibly creating more favorable 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. 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: 32768 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Sep 24 08:34:45 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 24 Sep 2012 11:34:45 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Mon, Sep 24 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Mon Sep 24 11:54:01 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 24 Sep 2012 14:54:01 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Mon, Sep 24 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Sep 25 08:38:41 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 25 Sep 2012 11:38:41 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 25 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Sep 25 08:47:56 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 25 Sep 2012 11:47:56 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 25 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Tue Sep 25 11:46:03 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 25 Sep 2012 14:46:03 -0400 Subject: [willamette-fcst] Field Burning Forecast for Silverton Hills - Tue, Sep 25 2012 Message-ID: An HTML attachment was scrubbed... URL: -------------- next part -------------- An HTML attachment was scrubbed... URL: From willamette-fcst at listsmart.osl.state.or.us Wed Sep 26 08:53:19 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 26 Sep 2012 08:53:19 -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 SEP 26, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: An upper-level ridge of high pressure is building back over the Pacific Northwest this morning. At the surface, a thermal trough is beginning to push northward along the southern Oregon coast, with weak pressure gradients across the Willamette Valley. Visible satellite imagery shows low clouds extending inland from the north coast, along the Columbia River, into the northern and central Willamette Valley. Skies are mostly clear over the remainder of the state, with the exception of areas of wildfire smoke, mainly from the Cascades eastward. The Salem sounding this morning and local pilot reports indicate that the marine layer is only about 2000 feet thick, so skies should clear by early afternoon. The air aloft has warmed several degrees since yesterday, so maximum mixing heights will be lower today. North to northeast transport winds will be unfavorable for burning. (Salem Airport data for Tuesday, Sept. 25th: High 75?F; Rainfall .00") TODAY'S FORECAST: Morning clouds with afternoon sunshine. Salem's high temperature today will be near 75 degrees (normal is 74). Relative humidity drops to near 60% around noon and to near 30% by 5 p.m. Surface winds: N to NE 5-10 mph. Transport winds: N to NE around 10 mph. Mixing height: Rising to near 2000 feet by noon and 3000 feet by 5 p.m. Salem's sunset tonight: 7:01 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 58 69 75 62 Relative Humidity: 64% 41% 30% 50% Surface Wind Dir/Speed: NE 5 N 6 N 8 N 6 Transport Wind Dir/Speed: NE 10 NE 10 N 12 N 10 Mixing Height: 1500 2500 3000 1500 Ventilation Index: 15 25 36 15 EXTENDED DISCUSSION: Little change in the weather pattern is forecast for Thursday, with a broad upper-level ridge of high pressure remaining parked over the Pacific Northwest. Expect sunny skies after areas of morning fog. Maximum temperatures should be about 5 degrees warmer than today. Continued northerly transport winds will be unfavorable for burning. On Friday, the upper-level ridge is forecast to shift eastward, to over the Rockies. Skies should remain mostly sunny, but increasing westerly flow aloft will force the thermal trough into eastern Oregon. That may turn transport winds enough onshore in the afternoon to create a burning opportunity. A weak cold front will pass mainly north of the state Friday night, with no precipitation expected in the Willamette Valley. High pressure is forecast to quickly rebuild across the region over the weekend. 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: 32256 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Sep 26 11:56:12 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 26 Sep 2012 11:56:12 -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 WED SEP 26, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: An upper-level ridge of high pressure is bringing dry and rather stagnant weather to the state today. At the surface, a thermal trough is beginning to push northward along the southern Oregon coast, with northerly pressure gradients beginning to increase across western Oregon. Visible satellite imagery shows a sliver low clouds persisting over the northern and central Willamette Valley at midday. Skies are mostly clear over the remainder of the state, with the exception of areas of wildfire smoke, mainly from the Cascades eastward. Skies should begin clearing shortly, but warm air aloft will suppress mixing today. North to northeast transport winds will be unfavorable for burning. TODAY'S FORECAST: Cloudy skies soon giving way to sunshine. Salem's high temperature today will be near 75 degrees (normal is 74). Relative humidity drops to near 50% around 2 p.m. and to near 35% by 5 p.m. Surface winds: N to NE 5-10 mph. Transport winds: N to NE around 10 mph. Mixing height: Rising to only about 2800 feet by 5 p.m. Salem's sunset tonight: 7:01 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 67 75 62 Relative Humidity: 50% 30% 50% Surface Wind Dir/Speed: N 6 N 8 N 6 Transport Wind Dir/Speed: NE 10 N 12 N 10 Mixing Height: 2200 2800 1500 Ventilation Index: 22 34 15 EXTENDED DISCUSSION: Little change in the weather pattern is forecast for Thursday, with a broad upper-level ridge of high pressure remaining parked over the Pacific Northwest. Expect sunny skies after areas of morning fog. Temperatures should be about 5 degrees warmer than today, with valley highs near 80?F. Continued northerly transport winds will be unfavorable for burning. On Friday, the upper-level ridge is forecast to shift eastward, to over the Rockies. Skies should remain mostly sunny, but increasing westerly flow aloft will force the thermal trough into eastern Oregon. Northwesterly transport winds may become strong enough to allow for the burning of remaining fields. A weak cold front will pass mainly north of the state Friday night, with no precipitation expected across western Oregon. High pressure is forecast to quickly rebuild across the region over the weekend. No significant change to the mostly dry and stagnant weather pattern is forecast by computer models for the next two weeks. 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: 32256 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Sep 27 08:58:34 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 27 Sep 2012 08:58:34 -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 SEP 27, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: Little change in the dry and stagnant weather pattern is forecast for today, with a broad upper-level ridge of high pressure remaining parked over the Pacific Northwest. The low-level air mass is much drier than yesterday, so marine clouds did not form in the valley this morning. Expect sunny skies with just some middle and high clouds today. Temperatures should be at least 5 degrees warmer than on Wednesday, with valley highs in the low 80s. The Salem sounding this morning showed several degrees of warming aloft compared to Wednesday, so mixing heights will be further suppressed today. A surface thermal trough is over western Oregon this morning with weak pressure gradients across the Willamette Valley. The trough is forecast to move over the Cascades later this afternoon. Light northerly transport winds will continue to be unfavorable for burning. (Salem Airport data for Wednesday, Sept. 26th: High 72?F; Rainfall .00") TODAY'S FORECAST: Mostly sunny and warm. Salem's high temperature today will be near 81 degrees (normal is 73). Relative humidity: Dropping below 60% by noon and to near 30% by 5 p.m. Surface winds: N 3-8 mph. Transport winds: N to NE 4-8 mph. Mixing height: Rising to near 2200 feet by 2 p.m. and 2700 feet by 5 p.m. Salem's sunset tonight: 6:59 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 64 76 80 68 Relative Humidity: 56% 36% 29% 49% Surface Wind Dir/Speed: N 3 N 4 N 6 N 4 Transport Wind Dir/Speed: N 4 N 5 N 8 N 6 Mixing Height: 1200 2200 2700 1000 Ventilation Index: 9 11 22 6 EXTENDED DISCUSSION: On Friday, the upper-level ridge is forecast to move over the Rockies with a weak westerly flow aloft over Oregon. A decaying cold front will likely bring some increasing middle and high clouds and force the thermal trough into eastern Oregon. Transport winds may turn enough northwesterly to allow for some burning, but ventilation conditions will be marginal, at best, due to continued warm air aloft and slow wind speeds. The weak cold front will pass mainly north of the state Friday night, with no precipitation expected across western Oregon. High pressure is forecast to quickly rebuild across the region this weekend and remain over us through most of next week. Long-range models now differ on their forecasts for late next week, with some indicating a possible change to cooler and damp weather and others maintaining dry and stagnant conditions across western Oregon. 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 Sep 27 11:56:47 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 27 Sep 2012 11:56:47 -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 THU SEP 27, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: Little change in the dry and stagnant weather pattern is forecast for today, with a broad upper-level ridge of high pressure remaining parked over the Pacific Northwest. A very weak upper-level disturbance is producing some middle and high clouds over mainly central and eastern Oregon. Skies are mostly sunny across western Oregon at midday, with the exception of low clouds and fog along the extreme south coast. Warm air aloft will keep mixing heights suppressed today. A surface thermal trough remains over western Oregon, at midday, with weak pressure gradients across the Willamette Valley. The trough is forecast to move only slightly east this afternoon. Light northerly transport winds will continue to be unfavorable for burning. Temperatures should be at least 5 degrees warmer than on Wednesday, with valley highs in the low 80s. TODAY'S FORECAST: Mostly sunny and warm. Salem's high temperature today will be near 81 degrees (normal is 73). Relative humidity: Dropping to near 30% by 5 p.m. Surface winds: N 3-8 mph. Transport winds: N to NE 4-8 mph. Mixing height: Rising to near 2200 feet by 2 p.m. and 2700 feet by 5 p.m. Salem's sunset tonight: 6:59 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 76 80 68 Relative Humidity: 36% 29% 49% Surface Wind Dir/Speed: N 4 N 6 N 4 Transport Wind Dir/Speed: N 5 N 8 N 6 Mixing Height: 2200 2700 1000 Ventilation Index: 11 22 6 EXTENDED DISCUSSION: On Friday, the upper-level ridge is forecast to move over the Rockies with a weak westerly flow aloft over Oregon. A decaying cold front will likely bring some increasing middle and high clouds and force the thermal trough into eastern Oregon. Transport winds may turn enough northwesterly to allow for some burning. However, ventilation conditions will be marginal, at best, due to continued warm air aloft and slow wind speeds. The weak cold front will pass mainly north of the state Friday night, with no precipitation expected across western Oregon. High pressure is forecast to quickly rebuild across the region this weekend. Northerly winds on Saturday will likely turn offshore on Sunday, with the potential to transport wildfire smoke back over the Willamette Valley. The upper-level ridge will stay anchored over the Pacific Northwest through at least Tuesday. Some long-range models are showing a breakdown of the ridge late next week, but that is not certain. 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: 32256 bytes Desc: Silverton Hills Midday Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Sep 28 08:56:46 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 28 Sep 2012 08:56:46 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT FRI SEP 28, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: Thursday's offshore transported wildfire smoke, from central Oregon, into the region. Air quality instruments this morning are showing elevated smoke levels across the Willamette Valley. The upper-level ridge has shifted east, to over the Rockies, with a weak westerly flow aloft over Oregon. A minor upper-air disturbance is producing considerable middle and high clouds across the state. A decaying cold front extends from Vancouver Island, British Columbia to about 400 miles off the Oregon coast. The increase in clouds did not allow for as much overnight cooling. Salem's sounding this morning showed warming below 3000 feet, but the air above 3000 feet was slightly cooler due to the eastward shift of the upper-level ridge. That has weakened the inversion over the valley, but mixing heights will still struggle to reach 3000 feet today, even with additional cooling aloft. A weak surface thermal trough is still over western Oregon this morning. Winds are light across the Willamette Valley. The trough is forecast to shift east of the Cascades this afternoon. That may turn transport winds northwesterly, but ventilation conditions will be only marginal, at best, due to continued warm air aloft and slow wind speeds. (Salem Airport data for Thursday, Sept. 27th: High 80?F; Rainfall .00") TODAY'S FORECAST: Mostly cloudy. Continued warm. Salem's high temperature today will be near 78 degrees (normal is 73). Relative humidity: Dropping to near 50% by 2 p.m. and to near 45% by 5 p.m. Surface winds: Light north; becoming light NW this afternoon. Transport winds: N 3-6 mph; becoming NW 4-8 mph this afternoon. Mixing height: Rising to near 2300 feet by 2 p.m. and 3000 feet by 5 p.m. Salem's sunset tonight: 6:57 p.m. THREE-HOURLY DATA: 11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 66 74 77 68 Relative Humidity: 63% 48% 44% 59% Surface Wind Dir/Speed: N 3 NW 3 NW 5 NW 4 Transport Wind Dir/Speed: N 5 NW 4 NW 6 NW 5 Mixing Height: 1000 2300 3000 1200 Ventilation Index: 5 9 18 6 EXTENDED DISCUSSION: A decaying cold front will pass mainly north of the state tonight, with the only precipitation expected to be areas of drizzle, mainly along the coast. High pressure is forecast to quickly rebuild across the region this weekend. Northerly winds on Saturday will likely turn offshore on Sunday, which will likely transport more wildfire smoke back over the Willamette Valley. The upper-level ridge will stay anchored over the Pacific Northwest through at least Tuesday, with the potential for strong offshore flow by Wednesday. Long-range computer models are now more consistent in maintaining a strong upper-level ridge of high pressure over the Pacific Northwest for the next 10 days, so there is no end in sight to our dry weather pattern. 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: 33280 bytes Desc: Silverton Hills AM Forecast.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Sep 28 11:58:16 2012 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 28 Sep 2012 11:58:16 -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 SEP 28, 2012 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. Propane flaming is not allowed. WEATHER DISCUSSION: The strong upper-level ridge that has been over the Pacific Northwest this week has shifted east of the region. A minor upper-air disturbance is producing considerable middle and high clouds across the state but little to no precipitation. Even though a weak westerly flow aloft has developed over Oregon, the air aloft remains quite warm and fairly stagnant. Air quality instruments are still showing elevated smoke levels across the Willamette Valley, from wildfires in central Oregon. A weak surface thermal trough, over western Oregon late this morning, is showing signs of shifting east, to over the Cascades. Winds continue to be light across the Willamette Valley. The thermal trough should slide east of the Cascades this afternoon. That may induce some northwesterly transport flow, but ventilation conditions will be only marginal, at best, due to continued warm air aloft and slow wind speeds. Transport winds will be monitored this afternoon, with pibals beginning at 1 p.m. TODAY'S FORECAST: Mostly cloudy. Continued warm. Salem's high temperature today will be near 78 degrees (normal is 73). Relative humidity: Dropping to near 50% by 2 p.m. and to near 45% by 5 p.m. Surface winds: Light north; becoming light NW later this afternoon. Transport winds: N 3-6 mph; becoming NW 4-8 mph later this afternoon. Mixing height: Rising to near 2300 feet by 2 p.m. and 3000 feet by 5 p.m. Salem's sunset tonight: 6:57 p.m. THREE-HOURLY DATA: 2 p.m. 5 p.m. 8 p.m. Temperature: 74 77 68 Relative Humidity: 48% 44% 59% Surface Wind Dir/Speed: NW 3 NW 5 NW 4 Transport Wind Dir/Speed: NW 4 NW 6 NW 5 Mixing Height: 2300 3000 1200 Ventilation Index: 9 18 6 EXTENDED DISCUSSION: A very weak cold front will pass mainly north of the state tonight, with only some areas of drizzle expected, mainly along the coast. High pressure is forecast to quickly rebuild across the region this weekend. Northerly winds on Saturday will turn offshore on Sunday, which will likely transport more wildfire smoke into the Willamette Valley. An upper-level ridge will stay anchored over the Pacific Northwest through at least Tuesday. Computer models are showing a strong offshore flow developing on Wednesday, which would maintain low mixing heights and likely transport even more wildfire smoke into western Oregon. The strong upper-level ridge is expected to maintain dry conditions through next 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. 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: 32256 bytes Desc: Silverton Hills Midday Forecast.doc URL: