From willamette-fcst at listsmart.osl.state.or.us Fri Aug 1 08:02:32 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 01 Aug 2008 10:02:32 -0500 Subject: [willamette-fcst] Forecast - Friday, August 1st, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 1st, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 2:00pm until 7:00pm. Preparatory burning is allowed from 2:00pm until 5:00pm with a 100 acre limit. Propane flaming is allowed from 2:00pm until 5:00pm. Straw stack burning is allowed from 2:00pm until 7:00pm. Weather Discussion: A weakening cold front was moving onto the Northern Oregon Coastline this morning and will likely stall over the Willamette Valley this afternoon. The front dumped up to one-half of an inch of rain along the Northern Washington Coast, since yesterday morning, with one-tenth to one-third of an inch falling in the northern interior of Western Washington. The front is drying out as it slowly moves southward with only spotty light rain expected today across NW Oregon. The north valley could see a few hundredths of an inch of rain, with only a chance of showers in the south valley. Some light rain was reported this morning along the Northern and Central Oregon Coast and in the extreme Northern Willamette Valley. Aurora picked up .01 inches with trace amounts as far south as Salem. The Salem sounding this morning showed cooling aloft, so mixing heights will likely reach 3000 feet later this afternoon, even with much cooler temperatures today. Cloudy skies should hold valley highs in the low 70s (about 10 degrees cooler than Thursday). Open burning is unlikely today due to marginal mixing heights and gradient-stacking issues. Ahead of the cold front, surface winds across the valley were southerly this morning at about 5-10 mph. Transport winds were southwesterly this morning and are expected to turn more westerly this afternoon, which is favorable for valley ventilation. Therefore, propane and prep burning is allowed later today. Some fields may get light rain between now and when burning is allowed this afternoon. Please note that burning is allowed only for fields that stay dry. Surface Winds: S 5-10 this morning, W 5-10 this afternoon. Transport Winds: SW 12 this morning, WSW 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 42. High Temperature: Salem\'s high temperature today will be near 72. Humidities: Minimum relative humidity will be near 51%. Sunrise/Sunset: Salem sunset tonight: 8:38pm; sunrise tomorrow: 5:59am. Extended Outlook: An upper-level trough will swing onshore this evening, in the wake of the cold front. Strong onshore flow will keep skies mostly cloudy tonight through much of Saturday. The trough will slowly weaken over the weekend, with onshore flow becoming more northerly and temperatures recoving to near normal by Sunday. A ridge of high pressure is forecast to build over the Pacific Northwest early next week. The low-level winds will turn north-northeasterly with valley temperatures possibly warming to near 90 degrees. Increasing south to southwesterly flow aloft is forecast for the second half of next week with an increased threat of thundershowers...mainly from the Cascades eastward. Increasing onshore flow may create a burn opportunity during the second half of next week, if the flow aloft is not too southerly. Tomorrow (02 Aug): Morning Clouds...Afternoon Clearing. 53/76 Sun (03 Aug): Patchy Morning Clouds...Sunny and Warmer in the Afternoon. 49/82 Mon (04 Aug): Sunny and Warm. 52/85 Tue (05 Aug): Mostly Sunny and Very Warm. 54/90 Wed (06 Aug): Partly Cloudy. Slight Chance of T-Storms Near the Cascades. 54/89 Thu (07 Aug): Partly Cloudy and Cooler. Slight Chance Showers/T-Storms. 56/84 Fri (08 Aug): Partly Cloudy. Slight Chance of a Shower. 55/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 4 08:02:05 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 04 Aug 2008 10:02:05 -0500 Subject: [willamette-fcst] Forecast - Monday, August 4th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, August 4th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A 52-day dry spell in Salem was broken Friday, as a weak cold front moved south across the Willamette Valley and dropped .03 inches of rain at the Salem Airport. The storm produced much greater precipitation totals in the Northeastern Willamette Valley, where upslope winds enhanced that rainfall. Up to .70 inches of rain fell, in the Corbett area, at the western end of the Columbia Gorge, and troutdale picked up about one-tenth of an inch. A weak upper-level trough, over Southern British Columbia, provided onshore flow and moderate temperatures across Western Oregon this past weekend. Valley highs were in the 70s both days with morning clouds and afternoon sunshine. The upper-level low pressure area had slid eastward this morning, and high pressure was rapidly building over the west coast. Weak onshore flow continued to push a shallow layer of low clouds onto the coastline, and locally into the coastal mountain gaps, this morning. Some low clouds made it up the Columiba River into the Portland area, while the remainder of the valley had clear skies this morning. Valley minimums were mostly near 50 degrees this morning. Hillsboro was one of the colder spots with a low of 47...followed closely by Eugene at 48. The Portland Airport was the warm spot with a minimum of 56. Visible satellite imagery this morning showed a blanket of low clouds west of the coast range with patchy low clouds along the Columbia River into the Portland area. The remainder of the state had cloud-free skies. California wildfire smoke was streaming over SW Oregon and northeastward across the southern half of Central and Eastern Oregon. The ODA surface analysis showed a thermal trough forming in the Willamette Valley with weak northerly gradients across Western Oregon. Northerly surface winds will prevail and increase this afternoon across the western valleys. Increasing offshore flow will drop relative humidities below 30 percent this afternoon, so Fire Marshal conditions may locally be met, if north winds increase to 15 mph or greater. The north winds should be strongest in the south valley. With the air aloft rapidly warming today, mixing heights will struggle to reach 3000 feet. a full day of sunshine and the lack of onshore flow will combine to lift valley temperatures into the upper 80s. Surface Winds: N 5-10 this morning, N 7-15 this afternoon. Transport Winds: NNE 10 this morning, NNE 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 88. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 26%. Sunrise/Sunset: Salem sunset tonight: 8:34pm; sunrise tomorrow: 6:03am. Extended Outlook: The upper-level ridge axis will be from SW Idaho through Central Washington Tuesday with weak southerly flow aloft over Oregon. That will increase the warming over the state and introduce a thundershower threat to Southern Oregon as early as Tuesday evening. Southerly flow aloft will increase Wednesday, as the upper-level ridge shifts eastward to over Western Montana. That will likely result in scattered thunderstorm development along most of the Cascade Range. If the flow aloft becomes southeasterly, thunderstorms could also make their way over the Willamette Valley Wednesday afternoon and evening. The surface flow will turn weakly onshore Tuesday, as the thermal trough shifts east of the Cascades. That will bring some cooling to Western Oregon and could create a burning opportunity, if the flow aloft is not too southerly. The upper-level winds are forecast to become more southwesterly Thursday and Friday, which will increase the onshore flow across Western Oregon with the bulk of the thundershower activity from the Cascades eastward Thursday and well east of the region Friday. That would also create another potential burning opportunity. An upper-level trough is forecast to move onshore over the weekend for even cooler conditions and increased onshore flow. Tomorrow (05 Aug): Sunny and Hot. 55/95 Wed (06 Aug): Mostly Sunny. Slight Chance of PM T-storm. 56/91 Thu (07 Aug): Partly Cloudy and Cooler. Slight Chance of T-storms near the Cascades. 57/85 Fri (08 Aug): Mostly Sunny and Cooler. 57/83 Sat (09 Aug): Partly Sunny with Continued Cooling. 54/79 Sun (10 Aug): Morning Clouds. Afternoon Clearing. 53/80 Mon (11 Aug): Mostly Sunny. 52/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 4 08:16:47 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 04 Aug 2008 10:16:47 -0500 Subject: [willamette-fcst] Forecast - Monday, August 4th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. ...Corrected wording in the extended forecast... ...Fire Marshal conditions may be met this afternoon due to low humidity and wind... Issued: Monday, August 4th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A 52-day dry spell in Salem was broken Friday, as a weak cold front moved south across the Willamette Valley and dropped .03 inches of rain at the Salem Airport. The storm produced much greater precipitation totals in the Northeastern Willamette Valley, where upslope winds enhanced that rainfall. Up to .70 inches of rain fell, in the Corbett area, at the western end of the Columbia Gorge, and troutdale picked up about one-tenth of an inch. A weak upper-level trough, over Southern British Columbia, provided onshore flow and moderate temperatures across Western Oregon this past weekend. Valley highs were in the 70s both days with morning clouds and afternoon sunshine. The upper-level low pressure area had slid eastward this morning, and high pressure was rapidly building over the west coast. Weak onshore flow continued to push a shallow layer of low clouds onto the coastline, and locally into the coastal mountain gaps, this morning. Some low clouds made it up the Columiba River into the Portland area, while the remainder of the valley had clear skies this morning. Valley minimums were mostly near 50 degrees this morning. Hillsboro was one of the colder spots with a low of 47...followed closely by Eugene at 48. The Portland Airport was the warm spot with a minimum of 56. Visible satellite imagery this morning showed a blanket of low clouds west of the coast range with patchy low clouds along the Columbia River into the Portland area. The remainder of the state had cloud-free skies. California wildfire smoke was streaming over SW Oregon and northeastward across the southern half of Central and Eastern Oregon. The ODA surface analysis showed a thermal trough forming in the Willamette Valley with weak northerly gradients across Western Oregon. Northerly surface winds will prevail and increase this afternoon across the western valleys. Increasing offshore flow will drop relative humidities below 30 percent this afternoon, so Fire Marshal conditions may locally be met, if north winds increase to 15 mph or greater. The north winds should be strongest in the south valley. With the air aloft rapidly warming today, mixing heights will struggle to reach 3000 feet. A full day of sunshine and the lack of onshore flow will combine to lift valley temperatures into the upper 80s. Surface Winds: N 5-10 this morning, N 7-15 this afternoon. Transport Winds: NNE 10 this morning, NNE 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 88. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 26%. Sunrise/Sunset: Salem sunset tonight: 8:34pm; sunrise tomorrow: 6:03am. Extended Outlook: The upper-level ridge axis will be from SW Idaho through Central Washington Tuesday with weak southerly flow aloft over Oregon. That will increase the warming over the state and introduce a thundershower threat to Southern Oregon as early as Tuesday evening. Southerly flow aloft will increase Wednesday, as the upper-level ridge shifts eastward to over Western Montana. That will likely result in scattered thunderstorm development along most of the Cascade Range. If the flow aloft becomes southeasterly, thunderstorms could also make their way over the Willamette Valley Wednesday afternoon and evening. The surface flow will turn weakly onshore Wednesday, as the thermal trough shifts east of the Cascades. That will bring some cooling to Western Oregon and could create a burning opportunity, if the flow aloft is not too southerly. The upper-level winds are forecast to become more southwesterly Thursday and Friday, which will increase the onshore flow across Western Oregon with the bulk of the thundershower activity from the Cascades eastward Thursday and well east of the region Friday. That would also create another potential burning opportunity. An upper-level trough is forecast to move onshore over the weekend for even cooler conditions and increased onshore flow. Tomorrow (05 Aug): Sunny and Hot. 55/95 Wed (06 Aug): Mostly Sunny. Slight Chance of PM T-storm. 56/91 Thu (07 Aug): Partly Cloudy and Cooler. Slight Chance of T-storms near the Cascades. 57/85 Fri (08 Aug): Mostly Sunny and Cooler. 57/83 Sat (09 Aug): Partly Sunny with Continued Cooling. 54/79 Sun (10 Aug): Morning Clouds. Afternoon Clearing. 53/80 Mon (11 Aug): Mostly Sunny. 52/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Aug 5 07:58:01 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 05 Aug 2008 09:58:01 -0500 Subject: [willamette-fcst] Forecast - Tuesday, August 5th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. ...Fire Marshal Conditions may locally be met this afternoon due to high temperatures and low humidities... Issued: Tuesday, August 5th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: An upper-level ridge of high pressure rapidly built over the west coast Monday with afternoon temperatures across the Willamette Valley warming into the upper 80s and low 90s. Increasing southerly flow aloft also spread smoke, from California wildfires, northward...creating hazy conditions over most of Oregon by Monday evening. The Salem sounding this morning showed several degrees of warming aloft since Monday morning with light southeasterly winds from near the surface through 7000 feet. Warm air aloft will, once again, cap mixing heights at or below 3000 feet...creating poor ventialtion conditions over the valley. The ODA surface analysis showed a broad thermal trough of low pressure extending from the NW tip of Washington through the Willamette Valley to SW Oregon. Weak onshore flow along the immediate coastline pushed a shallow layer of low clouds onto the coastline this morning. Visible satellite imagery showed mostly clear skies over the interior of Oregon. With the warmer air mass over the region, low temperatures only dipped into the mid 50s across the Willamette Valley this morning. Valley winds were light and variable. State Fire Marshal conditions may locally be met this afternoon, as temperatures approach 95 degrees and the humidity drops well below 30 percent. Afternoon winds will be in the 5-10 mph range, generally from the north. The upper-level ridge axis will shift eastward, to over Idaho, by tonight...increasing the south-southwesterly flow aloft and introducing a thundershower threat to extreme Southern Oregon by this evening. Surface Winds: Var 0-5 this morning, N 5-10 this afternoon. Transport Winds: SSE 3 this morning, N 7 this afternoon (with SE winds aloft). Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 21. High Temperature: Salem\'s high temperature today will be near 94. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 23%. Sunrise/Sunset: Salem sunset tonight: 8:32pm; sunrise tomorrow: 6:04am. Extended Outlook: Southerly flow aloft will increase Wednesday, with scattered thunderstorm development over Southern Oregon moving northward, mainly along the Cascades, in the afternoon. Thunderstorms could make their way over the Willamette Valley Wednesday evening. Valley temperatures will be similar to Tuesday. The surface flow may turn weakly onshore late in the day, as the broad thermal trough, over Western Oregon, begins to shift into Central Oregon. The upper-level winds are forecast to become more southwesterly Thursday and Friday, which will shift the thermal trough into Eastern Oregon and Idaho. Onshore flow will increase across Western Oregon with progressively cooler temperatures. Southwesterly flow aloft will bring more stable air onshore with the thundershowers shifting to the Cascades eastward Thursday and mainly over Idaho by Friday. The valley may see another significant burning opportunity Thursday and/or Friday, depending on the timing of the cool-down. An upper-level trough is forecast to move onshore over the weekend for further cooling with increased onshore flow. A transitory ridge of high pressure is forecast for early next week with increasing southwesterly flow aloft by the middle of the week. Tomorrow (06 Aug): Mostly Sunny. Slight Chance of PM T-storm. 59/91 Thu (07 Aug): Partly Cloudy and Cooler. Slight Chance of Showers/T-storms. 59/85 Fri (08 Aug): Partly Cloudy and Cooler. 56/81 Sat (09 Aug): Morning Clouds...Chance of Drizzle. Afternoon Clearing. 54/77 Sun (10 Aug): Morning Clouds. Mostly Sunny. 52/81 Mon (11 Aug): Sunny and Warmer. 53/87 Tue (12 Aug): Mostly Sunny. 55/85 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 6 11:33:45 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 06 Aug 2008 13:33:45 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 6th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 6th, 2008 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The Salem sounding this morning had a very similar temperature profile to Tuesday morning, so another warm day is on tap. However, middle and high clouds are blocking enough sunshine to keep things from warming up quite as fast today. Midday valley temperatures are ony near 70 degrees (about 5 degrees cooler than at the same time on Tuesday). Warm air aloft will, once again, yeild mixing heights below 3000 feet for much of today. The late-morning ODA surface analysis showed a thermal trough of low pressure extending from South-Central Washington through Western Oregon, but is is showing signs of drifting east, in response to the eastward progression of the upper-level ridge. Onshore flow is holding low clouds against both the Washington and Oregon Coastlines. The increasing southerly flow aloft brought middle and high-level moisture into Southern Oregon Tuesday night. Thundershower activity began in the early morning hours over South-Central Oregon with locally heavy rainfall reported in Klamath County. The storms moved along the Cascades this morning with the leading edge crossing the Columbia River at midday. The moist southerly flow aloft spread middle and high clouds northward across the Willamette Valley this morning, but the showers and thundershowers have stayed along the Cascades. Radar was showing an organized area of showers moving northward over Eastern Linn, Marion, and Clackamas Counties late this morning. Middle and high clouds will hold afternooon temperatures down a few degrees from Tuesday. In addition, some marine air may begin seeping through the coastal mountain gaps this afternoon and help to hold temperatures in the 80s. There is a chance that showers could roll off the Cascades over eastern sections of the valley... especially in the north this afternoon. Some cooing aloft may lift mixing heights over 3000 feet later this afternoon, but south-southeasterly winds at the top of the mixing layer and scattered thundershower development makes open-burning unlikely. A chance of showers or thundershowers will continue into the night with some clouds keeping overnight valley temperatures near 60 degrees. Surface Winds: Light...becoming NW 4-8 this afternoon. Transport Winds: SW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 25. High Temperature: Salem\'s high temperature today will be near 87. Humidities: Minimum relative humidity will be near 37%. Sunrise/Sunset: Salem sunset tonight: 8:31pm; sunrise tomorrow: 6:05am. Extended Outlook: As the upper-level ridge shifts east, to over Montana, the flow aloft over Oregon is forecast to become more southwesterly late Thursday and Friday. The thermal trough will shift eastward, into Eastern Oregon and Idaho, with increasing onshore flow across Western Oregon. That will bring increasing amounts of marine air into the Willamette Valley with progressively cooler temperatures. Southwesterly flow aloft will also push the moist and unstable air east, with the thundershowers shifting to Eastern Oregon and Idaho by Friday. The valley will have a better chance at an open-burning opportunity Thursday and/or Friday, depending on the timing of the cool-down, the degree of southerly flow aloft, and the location of showers and thundershowers. There is a good chance of showers or thunderstorms Thursday, but they should be out of the region Friday, with more favorable transport wind directions. However, we may have gradient-stacking issues and too much transport wind-speed Friday for good plume rise. The upper-level trough is forecast to move onshore over the weekend with the flow aloft turning westerly. Temperatures will cool further with increasing onshore flow possibly leading to areas of drizzle or light rain Saturday morning. A transitory ridge of high pressure is forecast for early next week with increasing southwesterly flow aloft by the middle of the week. Tomorrow (07 Aug): Mostly Cloudy and Cooler. Chance of Showers/T-storms. 60/83 Fri (08 Aug): Partly Cloudy and Cooler. 56/80 Sat (09 Aug): Morning Clouds...Chance of Drizzle. Afternoon Clearing. 54/75 Sun (10 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 50/79 Mon (11 Aug): Sunny and Warmer. 50/84 Tue (12 Aug): Sunny and Warm. 52/87 Wed (13 Aug): Mostly Sunny and Very Warm. 55/90 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 6 11:17:36 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 06 Aug 2008 13:17:36 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 6th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 6th, 2008 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The Salem sounding this morning had a very similar temperature profile to Tuesday morning, so another warm day is on tap. However, middle and high clouds are blocking enough sunshine to keep things from warming up quite as fast today. Midday valley temperatures are ony near 70 degrees (about 5 degrees cooler than at the same time on Tuesday). Warm air aloft will, once again, yeild mixing heights below 3000 feet for much of today. The late-morning ODA surface analysis showed a thermal trough of low pressure extending from South-Central Washington through Western Oregon, but is is showing signs of drifting east, in response to the eastward progression of the upper-level ridge. Onshore flow is holding low clouds against both the Washington and Oregon Coastlines. The increasing southerly flow aloft brought middle and high-level moisture into Southern Oregon Tuesday night. Thundershower activity began in the early morning hours over South-Central Oregon with locally heavy rainfall reported in Klamath County. The storms moved along the Cascades this morning with the leading edge crossing the Columbia River at midday. The moist southerly flow aloft spread middle and high clouds northward across the Willamette Valley this morning, but the showers and thundershowers have stayed along the Cascades. Radar was showing an organized area of showers moving northward over Eastern Linn, Marion, and Clackamas Counties late this morning. Middle and high clouds will hold afternooon temperatures down a few degrees from Tuesday. In addition, some marine air may begin seeping through the coastal mountain gaps this afternoon and help to hold temperatures in the 80s. There is a chance that showers could roll off the Cascades over eastern sections of the valley... especially in the north this afternoon. Some cooing aloft may lift mixing heights over 3000 feet later this afternoon, but south-southeasterly winds at the top of the mixing layer and scattered thundershower development makes open-burning unlikely. A chance of showers or thundershowers will continue into the night with some clouds keeping overnight valley temperatures near 60 degrees. Surface Winds: Light...becoming NW 4-8 this afternoon. Transport Winds: SW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 25. High Temperature: Salem\'s high temperature today will be near 87. Humidities: Minimum relative humidity will be near 37%. Sunrise/Sunset: Salem sunset tonight: 8:31pm; sunrise tomorrow: 6:05am. Extended Outlook: As the upper-level ridge shifts east, to over Montana, the flow aloft over Oregon is forecast to become more southwesterly late Thursday and Friday. The thermal trough will shift eastward, into Eastern Oregon and Idaho, with increasing onshore flow across Western Oregon. That will bring increasing amounts of marine air into the Willamette Valley with progressively cooler temperatures. Southwesterly flow aloft will also push the moist and unstable air east, with the thundershowers shifting to Eastern Oregon and Idaho by Friday. The valley will have a better chance at an open-burning opportunity Thursday and/or Friday, depending on the timing of the cool-down, the degree of southerly flow aloft, and the location of showers and thundershowers. There is a good chance of showers or thunderstorms Thursday, but they should be out of the region Friday, with more favorable transport wind directions. However, we may have gradient-stacking issues and too much transport wind-speed Friday for good plume rise. The upper-level trough is forecast to move onshore over the weekend with the flow aloft turning westerly. Temperatures will cool further with increasing onshore flow possibly leading to areas of drizzle or light rain Saturday morning. A transitory ridge of high pressure is forecast for early next week with increasing southwesterly flow aloft by the middle of the week. Tomorrow (07 Aug): Mostly Cloudy and Cooler. Chance of Showers/T-storms. 60/83 Fri (08 Aug): Partly Cloudy and Cooler. 56/80 Sat (09 Aug): Morning Clouds...Chance of Drizzle. Afternoon Clearing. 54/75 Sun (10 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 50/79 Mon (11 Aug): Sunny and Warmer. 50/84 Tue (12 Aug): Sunny and Warm. 52/87 Wed (13 Aug): Mostly Sunny and Very Warm. 55/90 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 6 10:28:51 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 06 Aug 2008 12:28:51 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 6th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 6th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Increasing southerly flow aloft spread smoke, from California wildfires, northward across most of Oregon by Monday evening. The southerly flow aloft increased Tuesday with more wildfire smoke making for hazy sunshine across Western Oregon. The air mass warmed considerably Tuesday with valley high temperatures climbing well into the 90s. Hillsboro was the warm spot with 98 degrees, Portland and Troutdale topped out at 97. Aurora, Salem, and Corvallis all hit 93 and Eugene hit 94. The Salem sounding this morning had a very similar temperature profile to Tuesday morning, so another warm day is on tap. Winds were light southwesterly below about 2000 feet...turning to southeasterly above 5000 feet. Warm air aloft will, once again, lead to mixing heights below 3000 feet for much of today. The ODA surface analysis showed the thermal trough of low pressure over the Willamette Valley showing signs of shifting into North-Central Oregon, in response to the upper-level ridge axis moving east to over Idaho. Onshore flow had brought low clouds onto both the Washington and Oregon Coastlines. Visible satellite imagery showed some low clouds making their way up the Columbia River. The increasing the southerly flow aloft brought middle and high-level moisture into Southern Oregon Tuesday night. Thundershower activity began in the early morning hours over South-Central Oregon with locally heavy rainfall reported in Klamath County. The storms were moving north into Deschutes County and extreme Eastern Lane County at mid-morning. The moist southerly flow aloft was also starting to spread middle and high clouds northward across the Willamette Valley with skies becoming mostly cloudy in the south valley. Increasing clouds will hold afternooon temperatures down a few degrees from Tuesday...especially in the south valley. In addition, some marine air will begin seeping through the coastal mountain gaps this afternoon and help to cap the daytime temperatures near 90 degrees. The increased moisture and instability will combine with daytime heating to trigger thundershowers this afternoon over the Cascades. There is a good chance that some of the storms will migrate over the Willamette Valley, this afternoon and evening, in the southeasterly flow aloft. Some cooing aloft may lift mixing heights over 3000 feet later this afternoon, but south-southeasterly winds aloft and scattered thundershower development makes open-burning unlikely. A chance of showers or thundershowers will continue into the night with mostly cloudy skies keeping overnight valley temperatures near 60 degrees. Surface Winds: SW 3-6 this morning, NW 5-10 this afternoon. Transport Winds: S 5 this morning, SW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 25. High Temperature: Salem\'s high temperature today will be near 91. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 29%. Sunrise/Sunset: Salem sunset tonight: 8:31pm; sunrise tomorrow: 6:05am. Extended Outlook: As the upper-level ridge shifts east, to over Montana, the flow aloft over Oregon is forecast to become more southwesterly late Thursday and Friday. The thermal trough will shift eastward, into Eastern Oregon and Idaho, with increasing onshore flow across Western Oregon. That will bring increasing amounts of marine air into the Willamette Valley with progressively cooler temperaures. Southwesterly flow aloft will also push the moist and unstable air eastward, with the thundershowers shifting to Eastern Oregon and Idaho by Friday. The valley may get an open-burning opportunity Thursday and/or Friday, depending on the timing of the cool-down, the degree of southerly flow aloft, and the location of showers and thundershowers. There is a good chance of showers or thunderstorms Thursday, but they should be out of the region Friday, with more favorable transport wind directions. However, we may have gradient-stacking issues and too much transport wind-speed Friday for good plume rise. The upper-level trough is forecast to move onshore over the weekend with the flow aloft turning westerly. Temperatures will cool further with increasing onshore flow possibly leading to areas of drizzle of light rain Saturday morning. A transitory ridge of high pressure is forecast for early next week with increasing southwesterly flow aloft by the middle of the week. Tomorrow (07 Aug): Mostly Cloudy and Cooler. Chance of Showers/T-storms. 60/83 Fri (08 Aug): Partly Cloudy and Cooler. 56/80 Sat (09 Aug): Morning Clouds...Chance of Drizzle. Afternoon Clearing. 54/75 Sun (10 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 50/79 Mon (11 Aug): Sunny and Warmer. 50/84 Tue (12 Aug): Sunny and Warm. 52/87 Wed (13 Aug): Mostly Sunny and Very Warm. 55/90 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 6 10:28:32 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 06 Aug 2008 12:28:32 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 6th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 6th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Increasing southerly flow aloft spread smoke, from California wildfires, northward across most of Oregon by Monday evening. The southerly flow aloft increased Tuesday with more wildfire smoke making for hazy sunshine across Western Oregon. The air mass warmed considerably Tuesday with valley high temperatures climbing well into the 90s. Hillsboro was the warm spot with 98 degrees, Portland and Troutdale topped out at 97. Aurora, Salem, and Corvallis all hit 93 and Eugene hit 94. The Salem sounding this morning had a very similar temperature profile to Tuesday morning, so another warm day is on tap. Winds were light southwesterly below about 2000 feet...turning to southeasterly above 5000 feet. Warm air aloft will, once again, lead to mixing heights below 3000 feet for much of today. The ODA surface analysis showed the thermal trough of low pressure over the Willamette Valley showing signs of shifting into North-Central Oregon, in response to the upper-level ridge axis moving east to over Idaho. Onshore flow had brought low clouds onto both the Washington and Oregon Coastlines. Visible satellite imagery showed some low clouds making their way up the Columbia River. The increasing the southerly flow aloft brought middle and high-level moisture into Southern Oregon Tuesday night. Thundershower activity began in the early morning hours over South-Central Oregon with locally heavy rainfall reported in Klamath County. The storms were moving north into Deschutes County and extreme Eastern Lane County at mid-morning. The moist southerly flow aloft was also starting to spread middle and high clouds northward across the Willamette Valley with skies becoming mostly cloudy in the south valley. Increasing clouds will hold afternooon temperatures down a few degrees from Tuesday...especially in the south valley. In addition, some marine air will begin seeping through the coastal mountain gaps this afternoon and help to cap the daytime temperatures near 90 degrees. The increased moisture and instability will combine with daytime heating to trigger thundershowers this afternoon over the Cascades. There is a good chance that some of the storms will migrate over the Willamette Valley, this afternoon and evening, in the southeasterly flow aloft. Some cooing aloft may lift mixing heights over 3000 feet later this afternoon, but south-southeasterly winds aloft and scattered thundershower development makes open-burning unlikely. A chance of showers or thundershowers will continue into the night with mostly cloudy skies keeping overnight valley temperatures near 60 degrees. Surface Winds: SW 3-6 this morning, NW 5-10 this afternoon. Transport Winds: S 5 this morning, SW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 25. High Temperature: Salem\'s high temperature today will be near 91. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 29%. Sunrise/Sunset: Salem sunset tonight: 8:31pm; sunrise tomorrow: 6:05am. Extended Outlook: As the upper-level ridge shifts east, to over Montana, the flow aloft over Oregon is forecast to become more southwesterly late Thursday and Friday. The thermal trough will shift eastward, into Eastern Oregon and Idaho, with increasing onshore flow across Western Oregon. That will bring increasing amounts of marine air into the Willamette Valley with progressively cooler temperaures. Southwesterly flow aloft will also push the moist and unstable air eastward, with the thundershowers shifting to Eastern Oregon and Idaho by Friday. The valley may get an open-burning opportunity Thursday and/or Friday, depending on the timing of the cool-down, the degree of southerly flow aloft, and the location of showers and thundershowers. There is a good chance of showers or thunderstorms Thursday, but they should be out of the region Friday, with more favorable transport wind directions. However, we may have gradient-stacking issues and too much transport wind-speed Friday for good plume rise. The upper-level trough is forecast to move onshore over the weekend with the flow aloft turning westerly. Temperatures will cool further with increasing onshore flow possibly leading to areas of drizzle of light rain Saturday morning. A transitory ridge of high pressure is forecast for early next week with increasing southwesterly flow aloft by the middle of the week. Tomorrow (07 Aug): Mostly Cloudy and Cooler. Chance of Showers/T-storms. 60/83 Fri (08 Aug): Partly Cloudy and Cooler. 56/80 Sat (09 Aug): Morning Clouds...Chance of Drizzle. Afternoon Clearing. 54/75 Sun (10 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 50/79 Mon (11 Aug): Sunny and Warmer. 50/84 Tue (12 Aug): Sunny and Warm. 52/87 Wed (13 Aug): Mostly Sunny and Very Warm. 55/90 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 6 09:56:01 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 06 Aug 2008 11:56:01 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 6th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 6th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Increasing southerly flow aloft spread smoke, from California wildfires, northward across most of Oregon by Monday evening. The southerly flow aloft increased Tuesday with more wildfire smoke making for hazy sunshine across Western Oregon. The air mass warmed considerably Tuesday with valley high temperatures climbing well into the 90s. Hillsboro was the warm spot with 98 degrees, Portland and Troutdale topped out at 97. Aurora, Salem, and Corvallis all hit 93 and Eugene hit 94. The Salem sounding this morning had a very similar temperature profile to Tuesday morning, so another warm day is on tap. Winds were light southwesterly below about 2000 feet...turning to southeasterly above 5000 feet. Warm air aloft will, once again, lead to mixing heights below 3000 feet for much of today. The ODA surface analysis showed the thermal trough of low pressure over the Willamette Valley showing signs of shifting into North-Central Oregon, in response to the upper-level ridge axis moving east to over Idaho. Onshore flow had brought low clouds onto both the Washington and Oregon Coastlines. Visible satellite imagery showed some low clouds making their way up the Columbia River. The increasing the southerly flow aloft brought middle and high-level moisture into Southern Oregon Tuesday night. Thundershower activity began in the early morning hours over South-Central Oregon with locally heavy rainfall reported in Klamath County. The storms were moving north into Deschutes County and extreme Eastern Lane County at mid-morning. The moist southerly flow aloft was also starting to spread middle and high clouds northward across the Willamette Valley with skies becoming mostly cloudy in the south valley. Increasing clouds will hold afternooon temperatures down a few degrees from Tuesday...especially in the south valley. In addition, some marine air will begin seeping through the coastal mountain gaps this afternoon and help to cap the daytime temperatures near 90 degrees. The increased moisture and instability will combine with daytime heating to trigger thundershowers this afternoon over the Cascades. There is a good chance that some of the storms will migrate over the Willamette Valley, this afternoon and evening, in the southeasterly flow aloft. Some cooing aloft may lift mixing heights over 3000 feet later this afternoon, but south-southeasterly winds aloft and scattered thundershower development makes open-burning unlikely. A chance of showers or thundershowers will continue into the night with mostly cloudy skies keeping overnight valley temperatures near 60 degrees. Surface Winds: SW 3-6 this morning, NW 5-10 this afternoon. Transport Winds: S 5 this morning, SW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 25. High Temperature: Salem\'s high temperature today will be near 91. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 29%. Sunrise/Sunset: Salem sunset tonight: 8:31pm; sunrise tomorrow: 6:05am. Extended Outlook: As the upper-level ridge shifts east, to over Montana, the flow aloft over Oregon is forecast to become more southwesterly late Thursday and Friday. The thermal trough will shift eastward, into Eastern Oregon and Idaho, with increasing onshore flow across Western Oregon. That will bring increasing amounts of marine air into the Willamette Valley with progressively cooler temperaures. Southwesterly flow aloft will also push the moist and unstable air eastward, with the thundershowers shifting to Eastern Oregon and Idaho by Friday. The valley may get an open-burning opportunity Thursday and/or Friday, depending on the timing of the cool-down, the degree of southerly flow aloft, and the location of showers and thundershowers. There is a good chance of showers or thunderstorms Thursday, but they should be out of the region Friday, with more favorable transport wind directions. However, we may have gradient-stacking issues and too much transport wind-speed Friday for good plume rise. The upper-level trough is forecast to move onshore over the weekend with the flow aloft turning westerly. Temperatures will cool further with increasing onshore flow possibly leading to areas of drizzle of light rain Saturday morning. A transitory ridge of high pressure is forecast for early next week with increasing southwesterly flow aloft by the middle of the week. Tomorrow (07 Aug): Mostly Cloudy and Cooler. Chance of Showers/T-storms. 60/83 Fri (08 Aug): Partly Cloudy and Cooler. 56/80 Sat (09 Aug): Morning Clouds...Chance of Drizzle. Afternoon Clearing. 54/75 Sun (10 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 50/79 Mon (11 Aug): Sunny and Warmer. 50/84 Tue (12 Aug): Sunny and Warm. 52/87 Wed (13 Aug): Mostly Sunny and Very Warm. 55/90 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 6 09:16:09 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 06 Aug 2008 11:16:09 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 6th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 6th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Increasing southerly flow aloft spread smoke, from California wildfires, northward across most of Oregon by Monday evening. The southerly flow aloft increased Tuesday with more wildfire smoke making for hazy sunshine across Western Oregon. The air mass warmed considerably Tuesday with valley high temperatures climbing well into the 90s. Hillsboro was the warm spot with 98 degrees, Portland and Troutdale topped out at 97. Aurora, Salem, and Corvallis all hit 93 and Eugene hit 94. The Salem sounding this morning had a very similar temperature profile to Tuesday morning, so another warm day is on tap. Winds were light southwesterly below about 2000 feet...turning to southeasterly above 5000 feet. Warm air aloft will, once again, lead to mixing heights below 3000 feet for much of today. The ODA surface analysis showed the thermal trough of low pressure over the Willamette Valley showing signs of shifting into North-Central Oregon, in response to the upper-level ridge axis moving east to over Idaho. Onshore flow had brought low clouds onto both the Washington and Oregon Coastlines. Visible satellite imagery showed some low clouds making their way up the Columbia River. The increasing the southerly flow aloft brought middle and high-level moisture into Southern Oregon Tuesday night. Thundershower activity began in the early morning hours over South-Central Oregon with locally heavy rainfall reported in Klamath County. The storms were moving north into Deschutes County and extreme Eastern Lane County at mid-morning. The moist southerly flow aloft was also starting to spread middle and high clouds northward across the Willamette Valley with skies becoming mostly cloudy in the south valley. Increasing clouds will hold afternooon temperatures down a few degrees from Tuesday...especially in the south valley. In addition, some marine air will begin seeping through the coastal mountain gaps this afternoon and help to cap the daytime temperatures near 90 degrees. The increased moisture and instability will combine with daytime heating to trigger thundershowers this afternoon over the Cascades. There is a good chance that some of the storms will migrate over the Willamette Valley, this afternoon and evening, in the southeasterly flow aloft. Some cooing aloft may lift mixing heights over 3000 feet later this afternoon, but south-southeasterly winds aloft and scattered thundershower development makes open-burning unlikely. A chance of showers or thundershowers will continue into the night with mostly cloudy skies keeping overnight valley temperatures near 60 degrees. Surface Winds: SW 3-6 this morning, NW 5-10 this afternoon. Transport Winds: S 5 this morning, SW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 25. High Temperature: Salem\'s high temperature today will be near 91. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 29%. Sunrise/Sunset: Salem sunset tonight: 8:31pm; sunrise tomorrow: 6:05am. Extended Outlook: As the upper-level ridge shifts east, to over Montana, the flow aloft over Oregon is forecast to become more southwesterly late Thursday and Friday. The thermal trough will shift eastward, into Eastern Oregon and Idaho, with increasing onshore flow across Western Oregon. That will bring increasing amounts of marine air into the Willamette Valley with progressively cooler temperaures. Southwesterly flow aloft will also push the moist and unstable air eastward, with the thundershowers shifting to Eastern Oregon and Idaho by Friday. The valley may get an open-burning opportunity Thursday and/or Friday, depending on the timing of the cool-down, the degree of southerly flow aloft, and the location of showers and thundershowers. There is a good chance of showers or thunderstorms Thursday, but they should be out of the region Friday, with more favorable transport wind directions. However, we may have gradient-stacking issues and too much transport wind-speed Friday for good plume rise. The upper-level trough is forecast to move onshore over the weekend with the flow aloft turning westerly. Temperatures will cool further with increasing onshore flow possibly leading to areas of drizzle of light rain Saturday morning. A transitory ridge of high pressure is forecast for early next week with increasing southwesterly flow aloft by the middle of the week. Tomorrow (07 Aug): Mostly Cloudy and Cooler. Chance of Showers/T-storms. 60/83 Fri (08 Aug): Partly Cloudy and Cooler. 56/80 Sat (09 Aug): Morning Clouds...Chance of Drizzle. Afternoon Clearing. 54/75 Sun (10 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 50/79 Mon (11 Aug): Sunny and Warmer. 50/84 Tue (12 Aug): Sunny and Warm. 52/87 Wed (13 Aug): Mostly Sunny and Very Warm. 55/90 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 6 08:10:39 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 06 Aug 2008 10:10:39 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 6th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 6th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Increasing southerly flow aloft spread smoke, from California wildfires, northward across most of Oregon by Monday evening. The southerly flow aloft increased Tuesday with more wildfire smoke making for hazy sunshine across Western Oregon. The air mass warmed considerably Tuesday with valley high temperatures climbing well into the 90s. Hillsboro was the warm spot with 98 degrees, Portland and Troutdale topped out at 97. Aurora, Salem, and Corvallis all hit 93 and Eugene hit 94. The Salem sounding this morning had a very similar temperature profile to Tuesday morning, so another warm day is on tap. Winds were light southwesterly below about 2000 feet...turning to southeasterly above 5000 feet. Warm air aloft will, once again, lead to mixing heights below 3000 feet for much of today. The ODA surface analysis showed the thermal trough of low pressure over the Willamette Valley showing signs of shifting into North-Central Oregon, in response to the upper-level ridge axis moving east to over Idaho. Onshore flow had brought low clouds onto both the Washington and Oregon Coastlines. Visible satellite imagery showed some low clouds making their way up the Columbia River. The increasing the southerly flow aloft brought middle and high-level moisture into Southern Oregon Tuesday night. Thundershower activity began in the early morning hours over South-Central Oregon with locally heavy rainfall reported in Klamath County. The storms were moving north into Deschutes County and extreme Eastern Lane County at mid-morning. The moist southerly flow aloft was also starting to spread middle and high clouds northward across the Willamette Valley with skies becoming mostly cloudy in the south valley. Increasing clouds will hold afternooon temperatures down a few degrees from Tuesday...especially in the south valley. In addition, some marine air will begin seeping through the coastal mountain gaps this afternoon and help to cap the daytime temperatures near 90 degrees. The increased moisture and instability will combine with daytime heating to trigger thundershowers this afternoon over the Cascades. There is a good chance that some of the storms will migrate over the Willamette Valley, this afternoon and evening, in the southeasterly flow aloft. Some cooing aloft may lift mixing heights over 3000 feet later this afternoon, but south-southeasterly winds aloft and scattered thundershower development makes open-burning unlikely. A chance of showers or thundershowers will continue into the night with mostly cloudy skies keeping overnight valley temperatures near 60 degrees. Surface Winds: SW 3-6 this morning, NW 5-10 this afternoon. Transport Winds: S 5 this morning, SW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 25. High Temperature: Salem\'s high temperature today will be near 91. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 29%. Sunrise/Sunset: Salem sunset tonight: 8:31pm; sunrise tomorrow: 6:05am. Extended Outlook: As the upper-level ridge shifts east, to over Montana, the flow aloft over Oregon is forecast to become more southwesterly late Thursday and Friday. The thermal trough will shift eastward, into Eastern Oregon and Idaho, with increasing onshore flow across Western Oregon. That will bring increasing amounts of marine air into the Willamette Valley with progressively cooler temperaures. Southwesterly flow aloft will also push the moist and unstable air eastward, with the thundershowers shifting to Eastern Oregon and Idaho by Friday. The valley may get an open-burning opportunity Thursday and/or Friday, depending on the timing of the cool-down, the degree of southerly flow aloft, and the location of showers and thundershowers. There is a good chance of showers or thunderstorms Thursday, but they should be out of the region Friday, with more favorable transport wind directions. However, we may have gradient-stacking issues and too much transport wind-speed Friday for good plume rise. The upper-level trough is forecast to move onshore over the weekend with the flow aloft turning westerly. Temperatures will cool further with increasing onshore flow possibly leading to areas of drizzle of light rain Saturday morning. A transitory ridge of high pressure is forecast for early next week with increasing southwesterly flow aloft by the middle of the week. Tomorrow (07 Aug): Mostly Cloudy and Cooler. Chance of Showers/T-storms. 60/83 Fri (08 Aug): Partly Cloudy and Cooler. 56/80 Sat (09 Aug): Morning Clouds...Chance of Drizzle. Afternoon Clearing. 54/75 Sun (10 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 50/79 Mon (11 Aug): Sunny and Warmer. 50/84 Tue (12 Aug): Sunny and Warm. 52/87 Wed (13 Aug): Mostly Sunny and Very Warm. 55/90 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Aug 7 08:02:23 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 07 Aug 2008 10:02:23 -0500 Subject: [willamette-fcst] Forecast - Thursday, August 7th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, August 7th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A moist and unstable south-southwesterly flow aloft will continue today over Oregon. Doppler radar showed showers and thundershowers this morning stretching from South-Central through NE Oregon. The storms in Central Oregon, over Northern Deschutes, Eastern Jefferson, and Northern Crook Counties, appeared quite strong on radar. Daytime heating will act to further destabilize the air mass and keep the showers and thundershowers going today...mainly from the Cascades eastward. The ODA surface analysis showed a broad thermal trough extending from South-Central Washington through Central Oregon. That appears to be the focus of the thunderstorm development this morning. Onshore flow is keeping low clouds against both the Washington and Oregon Coastlines with a greater penetration trough the coastal mountain gaps than on Wednesday morning. Marine low clouds were making it into the Willamette Valley this morning. They should give way to mostly sunny skies by midday. The Salem sounding this morning showed south-southwesterly winds aloft, and if those directions are maintained, then the showers and thundershowers will stay mainly east of the Cascades. However, it is possible that showers or thundershowers could swing more westward, to over the Willamette Valley, if the flow aloft turns more southerly later this afternoon and evening. The air aloft is only slightly cooler than on Wednesday, so mixing heights will remain below 3000 feet well into the afternoon. A filtering of marine air into the valley today should take a few degrees off of high temperatures this afternoon. More cooing aloft may lift mixing heights to near 4000 feet later this afternoon. If the flow aloft remains southwesterly, and the thunderstorm activity over Central Oregon moves further east, there is a chance that ventialtion conditions could become favorable for open burning this afternoon. Surface Winds: Var 0-5 this morning, NW 5-10 this afternoon. Transport Winds: SW 5 this morning, NW 5 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 20. High Temperature: Salem\'s high temperature today will be near 85. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 38%. Sunrise/Sunset: Salem sunset tonight: 8:30pm; sunrise tomorrow: 6:06am. Extended Outlook: As the upper-level ridge shifts east, to over Montana, the flow aloft over Oregon is forecast to become more southwesterly Friday. The thermal trough will shift eastward, into Eastern Oregon and Idaho, with increasing onshore flow across Western Oregon. Southwesterly flow aloft will also push the moist and unstable air east, with the thundershowers shifting to Eastern Oregon and Idaho. Southwesterly transport winds and higher mixing heights may create an open-burning opportunity Friday. However, that could be dampened, if too much marine air invades the valley overnight tonight. In addition, the low-level winds will be increasing Friday and may become too strong for good plume rise by the afternoon. The upper-level trough is forecast to move onshore over the weekend with the flow aloft turning westerly. Temperatures will cool further with increasing onshore flow possibly leading to areas of drizzle or light rain Saturday morning. A transitory ridge of high pressure is forecast for early next week. A trough is forecast to approach the coastline Tuesday afternoon, which could create another burning opportunity. Tomorrow (08 Aug): Slight Chance of AM Showers/T-storms...Partly Cloudy and Cooler. 58/80 Sat (09 Aug): Morning Clouds...Areas of Drizzle. Afternoon Clearing. 56/75 Sun (10 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 50/79 Mon (11 Aug): Sunny and Warmer. 50/84 Tue (12 Aug): Mostly Sunny and Warm. Increasing Onshore Flow Late. 52/87 Wed (13 Aug): Morning Clouds...Chance of Drizzle. Afternoon Clearing. 54/75 Thu (14 Aug): Morning Clouds. Afternoon Clearing. 54/77 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 8 08:03:14 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 08 Aug 2008 10:03:14 -0500 Subject: [willamette-fcst] Forecast - Friday, August 8th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 8th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A moist and very unstable south-southwesterly flow aloft helped generate multiple strong thunderstorms over Central Oregon Thursday. Golfball-sized hail was reported 12 miles NW of La Pine Thursday evening with multiple reports of one-half to three-quarter-inch diameter hail northwrd to the Washington border. An upper-level disturbance touched off more thundershowers over SW Oregon Thursday night that rolled up the Cascade crest and into Hood River about midnight. More storms developed early this morning over the Northern Cascades and moved through The Dalles around daybreak. Another batch of storms moved northeastward across NE Oregon this morning. The flow aloft over Oregon is starting to stabilize and become more southwesterly. Most of the shower and thundershower activity had moved north and east of the state by mid-morning. The Salem sounding showed a few degrees of cooling from the surface through 13,000 feet since Thursday morning, in response to an approaching upper-level trough about 300 miles offshore. The ODA surface analysis showed the thermal trough extending from SE Washington through Central Oregon and into SW Oregon. Onshore flow was a little stronger west of the Cascades this morning with marine low clouds extending inland to the Cascades. However, pilot reports indicate that the low clouds are only about 1300 feet thick, so an early afternoon break-out into sunshine is likely. Due to the weak influx of marine aire overnight, there is some gradient-stacking this morning, but afternoon heating should drop the pressures enough in the Willamette Valley to reverse that. Southwesterly aloft should stabiize the air mass over Central Oregon today, so thundershower development there is not likely. Mixing heights will stay below 3000 feet until surface temperatures climb into the low 70s this afternoon. The transport winds should have more of a westerly component this afternoon and cooler air aloft will help mixing heights climb to near 6000 feet, when surface temperatures hit about 80 degrees. If the marine layer breaks up, and allows the Willamette Valley to warm into the 70s this afternoon, there is a strong possibility that ventilation conditions will allow for open burning. The low-level winds will be increasing this afternoon and may become too strong for good plume rise by late in the day. A cold front is forecast to move onshore tonight and should significantly increase the onshore flow across the state. A thick low cloud-deck is likely Saturday morning with areas of drizzle across the valley...mainly in the north. Surface Winds: SW 4-8 this morning, W 7-15 this afternoon. Transport Winds: SSW 7 this morning, SW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5800 feet. Ventilation index 58. High Temperature: Salem\'s high temperature today will be near 80. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 41%. Sunrise/Sunset: Salem sunset tonight: 8:28pm; sunrise tomorrow: 6:08am. Extended Outlook: The upper-level trough is forecast to move onshore over the weekend with the flow aloft turning westerly. Temperatures will cool further Saturday with areas of morning drizzle or light rain likely...mainly in the north valley. A transitory ridge of high pressure is forecast for early next week. A weak trough is forecast to approach the coastline Tuesday, which could create another burning opportunity. A ridge is forecast for the end of next week with temperatures warming above normal and surface winds becoming mostly northerly. Tomorrow (09 Aug): Morning Clouds...Areas of Drizzle. Afternoon Clearing. 56/75 Sun (10 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 53/79 Mon (11 Aug): Sunny and Warmer. 50/85 Tue (12 Aug): Mostly Sunny and Warm. Increasing Onshore Flow Late. 52/87 Wed (13 Aug): Patchy Morning Clouds. Mostly Sunny. 53/85 Thu (14 Aug): Sunny and Warmer. 54/90 Fri (15 Aug): Sunny and Warm. 55/90 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 11 08:02:39 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 11 Aug 2008 10:02:39 -0500 Subject: [willamette-fcst] Forecast - Monday, August 11th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, August 11th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is allowed from 12:00pm until 5:00pm with a 100 acre limit. Propane flaming is allowed from 12:00pm until 5:00pm. Stack burning is not allowed. Weather Discussion: A cold front brought some light rain to the Oregon Coast and the Willamette Valley Saturday, along with well below normal temperatures. Rainfall amounts were generally only a couple hundredths of an inch, but Hillsboro did pick up just over one-tenth of an inch. Dry weather returned Sunday with temperatures warming close to normal. An upper-level ridge is forecast to move over Washington and Oregon today for further warming and drying of the air mass. Morning satellite imagery showed low clouds along much of the Oregon Coast, the Northern Willamette Valley, and in extreme North-Central Oregon. The remainder of the state was under mostly sunny skies. The areas of low clouds should give way to sunshine by this afternoon, even along the coast, as the low-level flow dries out and turns northerly. The ODA surface analysis showed very weak pressure gradients across Oregon. Valley winds were 3 mph or less this morning. The Salem sounding showed considerable warming aloft since Sunday morning, so temperatures will be about 5 degrees warmer today than on Sunday. Valley highs should climb into the mid 80s. Warming aloft will decrease maximum mixing heights, which climbed to more than 5000 feet Sunday afternoon, but they should still exceed 3000 feet by midday. However, forecast northerly transport winds, for this afternoon, makes open burning unlikely. Surface Winds: Var 0-4 this morning, N 5-15 this afternoon. Transport Winds: NW 2 this morning, N 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 32. High Temperature: Salem\'s high temperature today will be near 85. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 35%. Sunrise/Sunset: Salem sunset tonight: 8:24pm; sunrise tomorrow: 6:11am. Extended Outlook: A weak trough is forecast to move across Washington and Northern Oregon late Tuesday with little more than a few high clouds for the Willamette Valley. However, it may be strong enough to back the transport winds, from northerly to northwesterly. enough to allow for limited open burning. A strong ridge is forecast to rebuild over the Pacific Northwest during the second half of the week with the surface flow turning northerly again Wednesday and offshore Thursday. The ridge is forecast to shift eastward, to over Idaho, by late Friday. A weak upper-level disturbance is forecast to approach the Oregon Coast and may bring a bring a chance of thundershowers to the state Friday...mainly from the Cascades eastward. If the system arrives soon enoungh, it may create another burning opportunity, but that is too far out to call at this time. Another very weak trough is forecast to clip the region Sunday and cool temperatures to near normal. Tomorrow (12 Aug): Mostly Sunny and Warm. Wind: NW 5-15 mph. 55/85 Wed (13 Aug): Patchy Morning Clouds. Mostly Sunny. Wind: N 5-15 mph. 55/86 Thu (14 Aug): Sunny and Hot. Wind: NE 5-15 mph. 56/95 Fri (15 Aug): Mostly Sunny and Hot. Wind: Becoming NW 5-15 late. 57/95 Sat (16 Aug): Mostly Sunny and Warm. Wind: NW 5-15 mph. 57/90 Sun (17 Aug): Mostly Sunny & Cooler. 56/85 Mon (18 Aug): Mostly Sunny. 55/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Aug 12 08:03:07 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 12 Aug 2008 10:03:07 -0500 Subject: [willamette-fcst] Forecast - Tuesday, August 12th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Tuesday, August 12th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is allowed from 12:00pm until 2:00pm with a 100 acre limit. Propane flaming is allowed from 12:00pm until 5:00pm. Stack burning is not allowed. Weather Discussion: The upper-level ridge has flattened over Washington and Oregon today in response to a weakening cold front about 250 miles off the coast this morning. Satellite imagery showed high clouds from this system spreading across Western Washington and NW Oregon with low clouds blanketing the coastline and up the Columbia River into the Portland area. The remainder of Oregon was under sunny skies this morning with a more westerly flow aloft purging the California wildfire smoke from most of the state. A weak upper-level trough is forecast to move across Washington and Northern Oregon later today with increasing middle and high clouds across the Willamette Valley. The cold front may bring some sprinkles or light drizzle to the north coast tonight, but it should remain dry east of the coast range. Transport winds may back from northerly to northwesterly this afternoon, which may allow for limited open burning. Mixing heights will climb to 3000 feet around noon today with cooling aloft raising mixing heights to about 5000 feet by late this afternoon. An increase in the onshore flow will cap valley temperatures near or slightly below where they were Monday with highs in the mid 80s. However, the onshore flow will be weak and brief with northerly flow forecast to return to the valley by tonight, as high pressure rebuilds over the region. Surface Winds: NW 5-10 this morning, NW 7-15 this afternoon. Transport Winds: N 7 this morning, NW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5000 feet. Ventilation index 50. High Temperature: Salem\'s high temperature today will be near 84. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 40%. Sunrise/Sunset: Salem sunset tonight: 8:22pm; sunrise tomorrow: 6:12am. Extended Outlook: A strong ridge is forecast to rebuild over the Pacific Northwest Wednesday with the surface flow turning northerly and valley highs climbing into the mid to upper 80s. The ridge will amplify Thursday with warmer air aloft helping surface temperatures climb into the mid 90s across the Willamette Valley. An upper-level disturbance is forecast to approach the Oregon Coast Thursday, turning the flow aloft southerly and bringing a chance of thundershowers to the region Thursday evening throgh Friday morning. The upper-level disturbance is forecast to move northward along the Oregon and Washington Coastlines with flow aloft staying southerly through Friday. Southerly flow is not a good transport direction for valley smoke, so this system will not likely create a burning opportunity. It may force some marine air to filter into the valley Friday afternoon, but not enough to keep temperaturs from climbing into the 90s for the second straight day. Southerly flow aloft is forecast to continue the very warm weather Saturday with a slight increase in the onshore flow possibly cooling valley temperatures a few degrees. Saturday may be the third straight day with 90+ degree heat in the valley. The upper-level ridge is forecast to shift over Montana by Sunday with increasing southwesterly flow aloft over Oregon. That will bring more stable air into the region and increase the onshore flow for cooler temperatures across the interior of Western Oregon. The ridge is forecast to rebuild over the Pacific Northwest Monday with a weak trough flattening it and increasing the onshore flow again Tuesday. That transition may create a burning opportunity Tuesday or Wednesday of next week. Tomorrow (13 Aug): Mostly Sunny and Warmer. Wind: N 5-15 mph G25 south valley. 55/87 Thu (14 Aug): Mostly Sunny and Hot. Chance T-Storm Late. Wind: NNE 5-15 mph. 57/95 Fri (15 Aug): Partly Cloudy. Chance T-Storm. Wind: N 5-15. 59/95 Sat (16 Aug): Mostly Sunny and Very Warm. Slight Chance T-Storm. 60/92 Sun (17 Aug): Mostly Sunny and Cooler. Increasing Onshore Flow. 56/85 Mon (18 Aug): Sunny and Warmer. 54/88 Tue (19 Aug): Mostly Sunny. 56/86 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 13 08:03:23 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 13 Aug 2008 10:03:23 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 13th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 13th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A strong ridge is forecast to build over the Pacific Northwest, beginning today, with the surface flow turning northerly and valley highs climbing into the mid to upper 80s. The Salem sounding this morning showed north-northeasterly winds from just above the surface to about 3000 feet. The air mass aloft had not started warming much yet, so mixing hights should climb above 3000 feet this afernoon. North-northeasterly transport winds are expected to continue today. That is not conducive to good ventialtion for most of the valley but could create a burning opportunity for fields on the west side of the valley later this morning. The ODA surface analysis showed high pressure building into Western Washington with northerly gradients developing across Western Oregon. Valley winds were generally from the north at less than 10 mph with temperatures in the low to mid 60s. Satellite imgery showed mostly clear skies across Oregon, except for patchy low clouds along the coast and in the extreme north valley. The air mass will warm today in response to the building ridge over the region. Valley temperatures will climb into the upper 80s this afternoon with increasing north winds. Coastal locations will also see sunshine and northerly winds this afternoon with highs in the 65-75 degree range. Surface Winds: N 5-10 this morning, N 10-20 this afternoon. Transport Winds: NNE 13 this morning, NNE 13 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3700 feet. Ventilation index 48. High Temperature: Salem\'s high temperature today will be near 87. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 34%. Sunrise/Sunset: Salem sunset tonight: 8:21pm; sunrise tomorrow: 6:13am. Extended Outlook: We are in for a heat-wave. The upper-level ridge will amplify Thursday with warmer air aloft and offshore surface gradients lifting temperatures into the mid 90s across the Willamette Valley and the 70s to low 80s along the coast. Even with high afternoon surface temperatures, mixing heights will struggle to reach 3000 feet due to very warm air aloft. The upper-level ridge axis is forecast to shift east of the Cascades Friday afternoon with southerly flow aloft developing over Western Oregon. That will likely begin transporting smoke, from California wildfires, back over Western Oregon and make for hazy conditions. The air aloft will continue to warm with valley temperatures approaching daily record highs under a broad surface themal trough. An upper-level disturbance is forecast to approach the Oregon Coast Friday and begin to increase the moisture and instability over the western half of the state. The thermal trough may begin to shift east of the Cascades late Saturday, but not before temperatures climb to near the century mark in the valley for the second straight day. The upper-level ridge is forecast to shift over Western Montana Sunday with increasing southwesterly flow aloft over Oregon. That will bring more stable air into the region and increase the onshore flow for cooler temperatures across the interior of Western Oregon. The onshore flow will continue Monday with a stronger trough forecast to approach the coastline Tuesday. That system may create a burning opportunity Tuesday afternoon, before bringing a chance of light rain to Western Oregon Wednesday. Tomorrow (14 Aug): Sunny and Hot. 58/95 Fri (15 Aug): Sunny, Hot and Hazy. Slight Chance of T-Storms Late. 62/100 Sat (16 Aug): Mostly Sunny, Hot, and Hazy. Slight Chance of T-Storms. 62/98 Sun (17 Aug): Partly Cloudy and Much Cooler. 60/87 Mon (18 Aug): Mostly Sunny. 55/85 Tue (19 Aug): Mostly Sunny. 53/83 Wed (20 Aug): Mostly Cloudy and Cooler. Chance of Light Rain. 55/72 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Aug 14 08:03:50 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 14 Aug 2008 10:03:50 -0500 Subject: [willamette-fcst] Forecast - Thursday, August 14th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, August 14th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A strong ridge will continue building over the Pacific Northwest today with offshore surface flow. The Salem sounding this morning showed considerable warming aloft since Wednesday with north-northeasterly winds below 3000 feet. Temperatures are forecast to continue to warm aloft enough to support 100 degree heat in the Willamette Valley this afternoon. NNE transport winds are expected to continue today and are conducive to good ventilation of smoke from western valley fields. The morning ODA surface analysis showed a broad thermal trough of low pressure over Western Oregon with weak northerly gradients across the Willamette Valley. Surface winds were generally from the north at less than 10 mph across Western Oregon. Satellite imgery showed a narrow band of low clouds along the coast with clear skies over the remainder of Oregon. Temperatures were already quite warm with most of the western valleys near 70 degrees. It was cooler on the coast with readings near 60. The air mass aloft will continue to warm today in response to the building ridge over the region. Valley temperatures will approach daily record highs with increasing north to northeasterly winds. The combination of hot temperatures and low humidities should push the Willamette Valley into State Fire Marshal conditions around 2-3pm. The winds may also pick up enough to meet Fire Marshal criteria. Surface Winds: N 5-12 this morning, NNE 10-20 this afternoon. Transport Winds: NNE 15 this morning, NE 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 53. High Temperature: Salem\'s high temperature today will be near 100. Humidities: Minimum relative humidity will be near 23%. Sunrise/Sunset: Salem sunset tonight: 8:19pm; sunrise tomorrow: 6:15am. Extended Outlook: The upper-level ridge axis is forecast to shift far enough east Friday for southerly flow aloft to develop over Western Oregon. That will likely begin transporting smoke, from California wildfires, back over Western Oregon and begin to turn skies hazy. The air aloft will continue to warm. A broad thermal surface trough will remain over Western Oregon with offshore flow sending valley temperatures over the century mark...likely setting some new daily record highs. An upper-level disturbance is forecast to move close enough to the coastline Saturday to bring a threat of thundershowers to the state...mainly from the Cascades westward starting Saturday afternoon. The best chance of thunderstorms in the Willamette Valley appears to be Saturday night. The increasing southerly flow aloft may shift the thermal trough east of the Cascades late Saturday, which would cool temperatures a few degrees in the Willamette Valley. The upper-level ridge is forecast to shift over Western Montana Sunday with increasing southerly flow aloft spreading the chance of thunderstorms eastward across Oregon. The thermal trough is expected to shift to Eastern Oregon Sunday with onshore flow bringing some cooling to Western Oregon. There is considerable uncertainty in the long-range models regarding the transition out of the hot weather early next week. There could be burning opportunities early next week, depending on the strenghth and timing of the systems forecast to move onshore. The flow aloft is forecast to become southwesterly Monday, which would stabilize the air mass over Western Oregon and bring additional cooling with onshore flow. A stronger trough forecast to move onshore Tuesday. Either system may end up being strong enough to produce light showers across Western Oregon. Most of the computer models (not all) bring a significant trough onshore by Wednesday of next week. That would bring much cooler temperatures to the region and at least a chance of showers statewide. Tomorrow (15 Aug): Record Heat and Turning Hazy. 65/103 Sat (16 Aug): Mostly Sunny, Hot, and Hazy. Slight Chance of T-Storms Late. 65/99 Sun (17 Aug): Partly Cloudy. Slight Chance of T-storms. 60/90 Mon (18 Aug): Mostly Cloudy and Cooler. Chance of Showers. 55/75 Tue (19 Aug): Mostly Cloudy. Chance of Showers Late. 55/77 Wed (20 Aug): Mostly Cloudy and Cooler. Chance of Showers or Light Rain. 55/72 Thu (21 Aug): Mostly Cloudy. Chance of Showers. 55/70 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 15 08:03:11 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 15 Aug 2008 10:03:11 -0500 Subject: [willamette-fcst] Forecast - Friday, August 15th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 15th, 2008 at 9:00am. Burn Advisory: ...State Fire Marshal Conditions will likely be met this afternoon... Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A strong upper-level ridge of high pressure brought record high temperatures to the interior of Western Oregon Thursday. State Fire Marshal conditions were met by 3pm Thursday over most of the valley due to high temperatures and low humidities. Much of the Willamette Valley reached 100 degrees or better with Portland, Hillsboro, and Eugene hitting daily records. Medford also tied their daily record high of 108 degrees, set in 1933. Salem hit 100 degrees Thursday, but that was not a record for the date. Corvallis was the valley cool spot with a maximum of 99 degrees. The following records were tied or broken Thursday in the Willamette Valley: Location High Pervious Record Portland (Downtown) 101 97 set in 1942 Portland (Airport) 102 97 set in 1967 Hillsboro (Airport) 101 100 set in 1933 Eugene (Airport) 100 (tied) 100 set in 2002 The upper-level ridge had shifted over Eastern Washington and Eastern Oregon this morning with increasing southerly flow aloft feeding middle and high clouds over the western half of both states, along with the return of California wildfire smoke to much of Western Oregon. A weak upper-level disturbance was rotaing northward offshore and Doppler radar was showing shower activity just off the coast. The showers are not expected to make it inland but a few sprinkles could clip the coastal region today. The ODA surface analysis showed a strong thermal trough over the interior valleys of Western Oregon with low pressure centers near Portland and Medford. A high pressure center was near North Bend, along the southern coast. A weak influx of marine air was making it though the southern coastal gaps into Corvallis and Eugene, where temperatures had cooled into the low 60s. The north valley did not see any marine air overnight with minimums in the mid to upper 60s. Satellite imagery showed mostly clear skies from the Cascades eastward across Oregon and Idaho. To the west, coastal low clouds and fog blanketed the coastline this morning, in reponse to onshore flow induced by the thermal trough over western valleys. Some low clouds were penetrating into the coastal mountain gaps but none had made it into the Willamette Valley. The Salem sounding this morning showed very warm air aloft with easterly winds from near the surface up to 10,000 feet. A strong subsidence inversion had been created by the upper-level ridge and will cap mixing heights near 2000 feet today. In addition to poor ventilation conditions, State Fire Marshal Conditions will likely be met again this afternoon over much of the valley, especially north, due to high temperatures and low humidities. The upper-level ridge will hold fast today with record warm temperatures expected in the western valleys again this afternoon...especially from Salem north. The south valley will likely be a few degrees cooler due to the weak influx of marine air this morning. Low clouds and fog will keep the immediate coastline cool today with highs there only in the 60s. The onshore flow may turn enough northerly along the extreme north coast to clear skies there this afternoon...allowing temperatures to climb into the 70s. Light southerly flow aloft will continue to feed middle and high clouds over the region tonight with temperatures, once again, not dipping below 60 across most of the valley. Surface Winds: Var 5-10 north...SW 5-15 south this morning, N 5-10 north...NW 5-15 south this afternoon. Transport Winds: NE 10 north...W 10 south this morning, N 10 north...NW10 south this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2300 feet. Ventilation index 23. High Temperature: Salem\'s high temperature today will be near 100. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 24%. Sunrise/Sunset: Salem sunset tonight: 8:17pm; sunrise tomorrow: 6:16am. Extended Outlook: An upper-level disturbance is forecast to move close enough tothe coastline Saturday to bring a threat of showers or thundershowers to the western half of Oregon...especially the Southern Cascades. It will be another scorcher will most valley highs over the century mark for the third straight day. There is a pretty good chance of showers or thundershowers rolling off the Cascades and over the Willamette Valley Saturday evening and/or night. The upper-level ridge is forecast to shift to over Western Montana Sunday. Increasing southerly flow aloft will spread more mid and high-level moisture across Oregon with the chance of showers or thundershowers spreading eastward across the state. The thermal trough is forecast to finally shift east of the Cascades which will begin a cooling trend for Western Oregon. The flow aloft will turn southwesterly by Monday afternoon, which will stabilize the air mass and push the thundershower threat east of the region. It will also increase the onshore flow and bring a significant cool-down to Western Oregon. A weak cold front may be strong enough to produce some light showers along the coast and the Willamette Valley. A stronger system is still forecast to move onshore Tuesday afternoon or night for another chance of light rain across Western Oregon. Depending on the strength and timing of this system, it may create a burning upportunity ahead of it. The valley will have a good chance of showers Wednesday with the passing of a stronger upper-level trough. The flow aloft is forecast to turn northwesterly and begin drying out Thursday. Tomorrow (16 Aug): Sunny and Hot. Chance of T-Storms Late. 64/102 Sun (17 Aug): Mostly Cloudy. Chance of T-Storms. 62/92 Mon (18 Aug): Chance of AM T-Storms...Cooler with a Chance of Showers. 58/74 Tue (19 Aug): Partly Cloudy. Increasing Clouds Late with a Chance of Light Rain. 53/80 Wed (20 Aug): Chance of Showers and Cooler. 55/74 Thu (21 Aug): Mostly Cloudy. Slight Chance of Showers. 52/74 Fri (22 Aug): Morning Clouds...Afternoon Clearing. 50/78 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 15 11:01:17 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 15 Aug 2008 13:01:17 -0500 Subject: [willamette-fcst] Forecast - Friday, August 15th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. NOON UPDATE Issued: Friday, August 15th, 2008 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A strong upper-level ridge of high pressure brought record high temperatures to the interior of Western Oregon Thursday. State Fire Marshal conditions were met by 3pm Thursday over most of the valley due to high temperatures and low humidities. Much of the Willamette Valley reached 100 degrees or better with Portland, Hillsboro, and Eugene hitting daily records. Medford also tied their daily record high of 108 degrees, set in 1933. Salem hit 100 degrees Thursday, but that was not a record for the date. Corvallis was the valley cool spot with a maximum of 99 degrees. The following records were tied or broken Thursday in the Willamette Valley: Location High Pervious Record Portland (Downtown) 101 97 set in 1942 Portland (Airport) 102 97 set in 1967 Hillsboro (Airport) 101 100 set in 1933 Eugene (Airport) 100 (tied) 100 set in 2002 The upper-level ridge had shifted over Eastern Washington and Eastern Oregon this morning with increasing southerly flow aloft feeding middle and high clouds over the western half of both states, along with the return of some California wildfire smoke to much of Western Oregon. A weak upper-level disturbance was rotaing northward offshore and Doppler radar indicated some shower and thundershower activity off the Northern Oregon and Washington Coastlines moving north-northeastward. It it remain off the Oregon Coast but may clip the Washington Coast today. The late-morning ODA surface analysis showed a strong thermal trough over the interior valleys of Western Oregon with low pressure centers near Portland and Medford. High pressure centers were near North Bend, on the southern coast, and in NE Oregon near Baker City. A weak influx of marine air made it though the southern coastal gaps into the Southern Willamette Valley this morning. Late-morning temperatures in Corvallis and Eugene were 3-5 degrees cooler than at the same time Thursday. The north valley did not see the marine cooling, and late-morning temperatures are running a few degrees warmer than on Thursday. Satellite imagery showed mostly clear skies from the creast of the coast range eastward across Oregon. Low clouds continued to blanket the coastline late this morning with some sunbreaks along the north coast. Coastal temperatures ranged from the mid 50s sout to the mid 60s north. Western valley temperatures ranged from the mid 70s south to the low 80s north. The Salem sounding this morning showed warming aloft since Thursday, so high temperatures should easily break 100 degrees where the marine air did not penetrate this morning (from Salem north to Portland). A strong subsidence inversion had been created by the upper-level ridge and will cap mixing heights near 2000 feet today. State Fire Marshal Conditions will likely be met again by mid-afternoon, especially across the north valley, due to high temperatures and low humidities. Light southerly flow aloft tonight will continue to feed middle and high clouds over the region and hold minimums above 60 degrees. Surface Winds: Variable 5-15. Transport Winds: N to NW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2300 feet. Ventilation index 23. High Temperature: Salem\'s high temperature today will be near 103 (will be a record). Humidities: Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 8:17pm; sunrise tomorrow: 6:16am. Extended Outlook: An upper-level disturbance is forecast to move close enough to the coastline Saturday to bring a threat of showers or thundershowers to the western half of Oregon...especially the Southern Cascades. It will be another scorcher with most valley highs over the century mark for the third straight day. The increase in middle and high clouds may knock a couple of degrees off of the high temperatures. There is a pretty good chance that showers or thundershowers will roll off the Cascades and over the Willamette Valley Saturday evening and/or night. The upper-level ridge is forecast to shift to over Western Montana Sunday. Increasing southerly flow aloft will spread the chance of showers or thundershowers eastward across the state. The thermal trough is forecast to finally shift east of the Cascades Sunday afternoon, which will begin a cooling trend for Western Oregon. The flow aloft will turn southwesterly by Monday afternoon, which will stabilize the air mass and push the thundershower threat east of the Cascades. It will also increase the onshore flow and bring a significant cool-down to Western Oregon. A weak cold front may be strong enough to produce some light showers along the coast and the Willamette Valley. A stronger system is still forecast to move onshore Tuesday afternoon or night for another chance of light rain across Western Oregon. Depending on the strength and timing of this system, it may create a burning upportunity ahead of it Tuesday afternoon. The valley will have a good chance of showers Tuesday night and Wednesday. The flow aloft is forecast to turn northwesterly and begin drying out Thursday. Tomorrow (16 Aug): Sunny and Hot. Chance of T-Storms Late. 64/102 Sun (17 Aug): Mostly Cloudy. Chance of T-Storms. 62/92 Mon (18 Aug): Chance of AM T-Storms...Cooler with a Chance of Showers. 58/74 Tue (19 Aug): Partly Cloudy. Increasing Clouds Late with a Chance of Light Rain. 53/80 Wed (20 Aug): Chance of Showers and Cooler. 55/74 Thu (21 Aug): Mostly Cloudy. Slight Chance of Showers. 52/74 Fri (22 Aug): Morning Clouds...Afternoon Clearing. 50/78 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 18 08:03:48 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 18 Aug 2008 10:03:48 -0500 Subject: [willamette-fcst] Forecast - Monday, August 18th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, August 18th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The strong upper-level ridge of high pressure that brought triple-digit heat to the Willamette Thursday-Saturday of last week shifted eastward to over over Idaho Sunday. Increasing moist and unstable southerly flow aloft triggered shower and thundershower activity across the western half of Oregon Saturday night and Sunday. The surface thermal trough, and 100+ temperatures, shifted east of the Cascades Sunday. Pendleton was the warm spot in Oregon Sunday with a record shattering high of 108 degrees. The old daily record was 104 degrees set in 1934. Meanwhile, the increased cloud-cover and onshore flow held Western Oregon temperatures into the 80s Sunday afternoon. The ridge had shifted to over Montana this morning with a very moist and unstable southerly flow aloft continuing to produce numerous showers and thundershowers across Western and Central Oregon. Doppler radar showed large areas of showers and thundershowers along the central Oregon Coast, the northern Willamette Valley, and from south-central Oregon through the northern Cascades this morning. The storms were being carried northward by the southerly flow aloft. The morning ODA surface analysis showed a strong thermal low-pressure center over eastern Washington with a thermal trough extending through central Oregon to Sw Oregon. Onshore flow was continuing to bring cooler low-level air into the Willamette Valley. Western Oregon temperatures were only in the low 60s with numerous showers and a few lightning strikes. Satellite imagery showed cloud bands circulating northward around an upper-level disturbance, centered near the southern Oregon Coast. That system will very slowly move onshore later this afternoon...maintaining the moist and unstable southerly flow aloft over Western Oregon today. High humidities, damp fields, and continued showers makes open burning unlikely this afternoon. Surface Winds: SW 5-15 this morning, WSW 5-15 this afternoon. Transport Winds: SW 10 this morning, SW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 35. High Temperature: Salem\'s high temperature today will be near 76. Humidities: Minimum relative humidity will be near 56%. Sunrise/Sunset: Salem sunset tonight: 8:13pm; sunrise tomorrow: 6:19am. Extended Outlook: The flow aloft will turn southwesterly by tonight, which will stabilize the air mass and push the thundershower threat east of the Cascades. It will also maintain the cool onshore flow across Western Oregon. An unseasonably strong weather system is still forecast to move onshore late Tuesday afternoon or night for a general rain across Western Oregon. Depending on the timing of this system, it may create a burning upportunity ahead of it Tuesday afternoon, if conditions are dry enough. The valley will have a good chance of showers Wednesday. The flow aloft is forecast to turn northwesterly and begin drying out Thursday afternoon. Tomorrow (19 Aug): Mostly Cloudy. Good Chance of Rain Late. 59/76 Wed (20 Aug): Rain Turning to Showers. 59/70 Thu (21 Aug): Mostly Cloudy. Slight Chance of Showers. 56/71 Fri (22 Aug): Mostly Sunny. 51/80 Sat (23 Aug): Mostly Sunny. 50/85 Sun (24 Aug): Mostly Sunny. 52/85 Mon (25 Aug): Moslty Sunny. 54/86 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 18 11:04:43 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 18 Aug 2008 13:04:43 -0500 Subject: [willamette-fcst] Forecast - Monday, August 18th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. NOON UPDATE Issued: Monday, August 18th, 2008 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The upper-level ridge that gave us the recent hot spell had shifted to over Montana late this morning. A very moist and unstable southerly flow aloft was continuing to generate showers and thundershowers across Western and Central Oregon. Doppler radar and satellite imagery showed two distinct lines of showers and thundershowers late this morning. One stretched from the Seattle, Wsahington region through North-Central Oregon, and the other from near Astoria, Oregon southeastward through the Willamette Valley. The line of showers of the Willamette Valley appeared to be weakening, but there were still likely a couple of thundershowers left. There was quite a range of rainfall totals from the storms this morning, due to the showery nature of the precipitation. Reported rainfall amounts in the valley, as of 11am, ranged from just .01\" and .03\" at the Eugene and Salem Airports to .23\" at the Aurora Airport. The late-morning ODA surface analysis showed a strong thermal low-pressure center over NE Washington with a thermal trough extending through East-Central Oregon to South-Central Oregon. Onshore flow was continuing to bring cooler low-level air into the Willamette Valley. Western Oregon temperatures were only in the low 60s. Satellite imagery showed cloud bands circulating northward around an upper-level disturbance, centered near the southern Oregon Coast. That system will very slowly move onshore this afternoon...maintaining the moist and unstable southerly flow aloft over Western Oregon this afternoon. High humidities, damp fields, and continued showers makes open burning unlikely this afternoon. Surface Winds: SW 5-15 this afternoon. Transport Winds: WSW 08 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 72. Humidities: Minimum relative humidity will be near 64%. Sunrise/Sunset: Salem sunset tonight: 8:13pm; sunrise tomorrow: 6:19am. Extended Outlook: The flow aloft will turn southwesterly overnight, which will stabilize the air mass west of the Cascades and push the thundershower threat over Eastern Oregon. Onshore flow will keep skies mostly cloudy with a continued chance of a light shower across the Willamette Valley. An unseasonably strong weather system is forecast to move onshore late Tuesday afternoon and night for a general rain across Western Oregon. Depending on the timing of this system, it may create a burning upportunity Tuesday afternoon, if conditions dry out enough. The valley will likely pick a general rain Tuesday night and Wednesday morning with showers continuing through Wednesday. Total rainfall amounts should exceed one-tenth of an inch and may approach one-half inch. The flow aloft is forecast to turn northwesterly and begin drying out Thursday afternoon with a return of more summer-like weather as we head into the weekend. Tomorrow (19 Aug): Mostly Cloudy. Good Chance of Rain Late. 59/76 Wed (20 Aug): Rain Turning to Showers. 59/70 Thu (21 Aug): Mostly Cloudy. Slight Chance of Showers. 56/71 Fri (22 Aug): Mostly Sunny. 51/80 Sat (23 Aug): Mostly Sunny. 50/85 Sun (24 Aug): Mostly Sunny. 52/85 Mon (25 Aug): Moslty Sunny. 54/86 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 18 11:22:26 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 18 Aug 2008 13:22:26 -0500 Subject: [willamette-fcst] Forecast - Monday, August 18th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. ...Corrected Extended Forecast... NOON UPDATE Issued: Monday, August 18th, 2008 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The upper-level ridge that gave us the recent hot spell had shifted to over Montana late this morning. A very moist and unstable southerly flow aloft was continuing to generate showers and thundershowers across Western and Central Oregon. Doppler radar and satellite imagery showed two distinct lines of showers and thundershowers late this morning. One stretched from the Seattle, Wsahington region through North-Central Oregon, and the other from near Astoria, Oregon southeastward through the Willamette Valley. The line of showers of the Willamette Valley appeared to be weakening, but there were still likely a couple of thundershowers left. There was quite a range of rainfall totals from the storms this morning, due to the showery nature of the precipitation. Reported rainfall amounts in the valley, as of 11am, ranged from just .01\" and .03\" at the Eugene and Salem Airports to .23\" at the Aurora Airport. The late-morning ODA surface analysis showed a strong thermal low-pressure center over NE Washington with a thermal trough extending through East-Central Oregon to South-Central Oregon. Onshore flow was continuing to bring cooler low-level air into the Willamette Valley. Western Oregon temperatures were only in the low 60s. Satellite imagery showed cloud bands circulating northward around an upper-level disturbance, centered near the southern Oregon Coast. That system will very slowly move onshore this afternoon...maintaining the moist and unstable southerly flow aloft over Western Oregon this afternoon. High humidities, damp fields, and continued showers makes open burning unlikely this afternoon. Surface Winds: SW 5-15 this afternoon. Transport Winds: WSW 08 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 72. Humidities: Minimum relative humidity will be near 64%. Sunrise/Sunset: Salem sunset tonight: 8:13pm; sunrise tomorrow: 6:19am. Extended Outlook: The flow aloft will turn southwesterly overnight, which will stabilize the air mass west of the Cascades and push the thundershower threat over Eastern Oregon. Onshore flow will keep skies mostly cloudy with a continued chance of a light shower across the Willamette Valley. An unseasonably strong weather system is forecast to move onshore late Tuesday afternoon and night for a general rain across Western Oregon. Depending on the timing of this system, it may create a burning upportunity Tuesday afternoon, if conditions dry out enough. The valley will likely pick a general rain Tuesday night and Wednesday morning with showers continuing through Wednesday. Total rainfall amounts should exceed one-tenth of an inch and may approach one-half inch. The flow aloft is forecast to turn northwesterly and begin drying out Thursday afternoon with a return of more summer-like weather as we head into the weekend. There is disagreement among the computer models as to how long this warm dry period will last. There is a chance that a cold front will bring cooler weather and a chance of rain as early as Sunday night. However, some computer models hold it offshore until Tuesday. Tomorrow (19 Aug): Mostly Cloudy. Good Chance of Rain Late. 59/76 Wed (20 Aug): Rain Turning to Showers. 59/70 Thu (21 Aug): Mostly Cloudy. Slight Chance of Showers. 56/71 Fri (22 Aug): Mostly Sunny. 51/80 Sat (23 Aug): Mostly Sunny. 50/85 Sun (24 Aug): Mostly Sunny. Increasing Clouds Late. 52/85 Mon (25 Aug): Mostly Cloudy. Increasing Chance of Rain and Cooler. 58/74 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Aug 19 08:04:07 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 19 Aug 2008 10:04:07 -0500 Subject: [willamette-fcst] Forecast - Tuesday, August 19th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Tuesday, August 19th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A moist and unstable southerly flow aloft brought numerous showers and thundershowers to Western Oregon Monday. Rainfall amounts were greatest in the north valley with several loactions receiving up to one-quarter of an inch. Most of the south valley recorded less than one-tenth of an inch. The upper-level trough came onshore last night with the flow aloft turning southwesterly. That stabilized the air mass west of the Cascades, but a few showers continued through early this morning. The upper-level trough was shifting east of the region at mid-morning with the flow aloft drying out and becoming more westerly. Doppler radar showed a few very light showers over the valley, but they were weakening. Satellite imagery showed a few breaks in the low clouds over the valley. The ODA surface analysis showed weak high pressure over Western Oregon, ahead of a very impressive system offshore. Gradients across the valley were weak southerly with south winds in the 5-10 mph range common. Temperatures were in the low 60s. The Salem sounding this morning showed considerable cooling aloft since Monday morning, so mixing heights should climb over 3000 feet as soon as surface temperatures reach the upper 60s. Transport winds were southwesterly. With a few sunbreaks today, surface temperatures may reach the low to mid 70s. That would yield mixing heights above 4000 feet. That may create an opportunity for open burning of dry fields when humidity levels drop below 65 percent. A very impressive weather system for mid-August was about 300 miles offshore at mid-morning. The high clouds ahead of it were already approaching the coastline. It will likely warm the air mass aloft slighly this afternoon, which will tend to shut down the shower activity and help warm the air mass. Rain is forecast to reach the coastline by late this afternoon and move into the Willamette Valley this evening. Surface Winds: S 5-12 this morning, SW 8-15 this afternoon. Transport Winds: SSW 12 this morning, SW 20 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4800 feet. Ventilation index 96. High Temperature: Salem\'s high temperature today will be near 73. Humidities: Minimum relative humidity will be near 58%. Sunrise/Sunset: Salem sunset tonight: 8:11pm; sunrise tomorrow: 6:21am. Extended Outlook: An unseasonably strong weather system is forecast to move onshore tonight with blustery winds along the coast and a soaking rainfall across the Willamette Valley. The steady rain will turn to showers Wednesday afternoon with a strong upper-level trough keeping the showers going through Thursday. Total rainfall amounts will generally exceed one-half inch in the north valley and one-quarter inch in the south valley. Some computer models have total rainfall amounts in the north valley exceeding an inch, so this system appears as if it will be unusually moist. The flow aloft is forecast to turn northwesterly and begin drying out Thursday night with a return of more summer-like weather as we head into the weekend. That will give fields at least 2-3 days to dry, before the next weather system comes onshore early next week. There is disagreement among the computer models as to how long this warm dry period will last. It is possible that another fairly potent weather system could bring more rain to the valley as early as Sunday night. Tomorrow (20 Aug): Rain Turning to Showers. 59/70 Thu (21 Aug): Mostly Cloudy. Showers Likely...Mainly North. 56/74 Fri (22 Aug): Mostly Sunny & Warmer. 50/80 Sat (23 Aug): Sunny and Warm. 52/85 Sun (24 Aug): Mostly Sunny. Increasing Clouds Late. 54/85 Mon (25 Aug): Mostly Cloudy and Cooler with a Chance of Rain. 58/74 Tue (26 Aug): Mostly Cloudy. Chance of Showers. 55/74 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 20 07:52:59 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 20 Aug 2008 09:52:59 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 20th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 20th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: An unseasonably strong Pacific storm system spread rain into Western Oregon Tuesday afternoon that continued through the night. Rainfall totals along the coast ranged from nearly an inch at Astoria to about one-third of inch from Newport and North Bend. In the Willamette Valley, the heaviest rainfall was also in the north with the north valley getting about one-quarter of an inch and the south valley about one-tenth of an inch overnight. Rain aksi spread east of the Cascades overnight with up to one-tenth of an inch falling across North-Central and NE Oregon. Satellite imagery showed generally cloudy skies over all of Washington and Oregon this morning. Doppler radar showed considerable coverage of rainfall across Washingtonand the northern third of Oregon. A line of showers, associated with the surfacecold front, was pushing through the Willamette Valley with a break in the rain showing up over the northern coast range. The cold front was moving across the Willamette Valley at mid-morning and will push east of the Cascades this afternoon. There will likely be a let-up in the rain, and a few sunbreaks, in the wake of the cold front later this morning. However, a strong upper-level trough will bring vigorous showers to Western Oregon this afternoon through most of Thursday with rainfall totals across the valley likely tripling by Thursday night. Temperatures will be at least 10 degrees below normal today. Highs will only climb to near 70 with breezy southwesterly winds. Surface Winds: S 10-20 this morning, SW 10-20 this afternoon. Transport Winds: SSW 22 this morning, SW 25 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2000 feet. Ventilation index 50. High Temperature: Salem\'s high temperature today will be near 70. Humidities: Minimum relative humidity will be near 70%. Sunrise/Sunset: Salem sunset tonight: 8:09pm; sunrise tomorrow: 6:22am. Extended Outlook: A strong upper-level trough will keep the showers going through Thursday. Total rainfall amounts, since Tuesday evening, will likely be one-half to one inch in the north valley and one-quarter to three-quarters of an inch in the south valley. Some locations...especially near the Cascade foothills, may get over an inch. A flat transitory ridge of high pressure will dry things out and warm temperatures back to near normal Friday with some sunshine. The flow aloft will turn southwesterly Saturday in response to a large upper-level trough in the Gulf of Alaska. That will bring further warming to Western Oregon, which will air in the drying of damp fields. The upper-level trough is forcast to move closer to the coastline Sunday with increasing southwesterly flow aloft. That will likely increase the onshore flow Sunday afternoon with high temperatures staying in the 80s. A Pacific cold front is forecast to come onshore Monday that could bring another quarter-inch or more of rain to the Willamette Valley...especially north. The current timing of this system is too quick for a burning opportunity Monday, before the rain sets in, but that will need to be watched closely. Another flat ridge will dry and warm the air mass Tuesday with the flow aloft turning soutwesterly again Wednesday. Tomorrow (21 Aug): Mostly Cloudy. Showers Likely...Mainly North. 56/71 Fri (22 Aug): Mostly Sunny & Warmer. 50/80 Sat (23 Aug): Sunny and Warm. 52/85 Sun (24 Aug): Mostly Sunny. Increasing Clouds Late. 54/85 Mon (25 Aug): Good Chance of Rain and Cooler. 58/72 Tue (26 Aug): Partly Cloudy and Warmer. 50/78 Wed (27 Aug): Mostly Sunny Early...Increasing Clouds with a Chance of Rain Late. 53/81 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Aug 21 07:53:33 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 21 Aug 2008 09:53:33 -0500 Subject: [willamette-fcst] Forecast - Thursday, August 21st, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, August 21st, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A strong upper-level trough continued to circulate vigorous shower activity across the northern half of Oregon overnight and centered over northern Washington this morning. Rainfall amounts in the 24 hours ending at 5am were, for the most part, greater than the previous 24 hours. The northern Willamette Valley picked up around one-third of an inch of rain with over one-tenth of an inch in the south valley. Two-day totals were around one-quarter of an inch in the south valley and about one-half inch in the north valley. The upper-level trough is moving east and the flow aloft is forecast to turn northwesterly and begin drying and warming this afternoon. Doppler radar has shown a general decrease in the shower activity over Western Oregon during the past couple of hours and satellite imagery is even showing a few breaks in the overcast skies. Additional precipitation amounts today should be less than one-tenth of an inch with the showers liekly ending by mid-afternoon. The Salem sounding this morning showed even more cooling aloft, with the freezing level clear down to 8100 feet, so temperatures will remain quite cool today, even with a little sunshine. The ODA surface analysis showed high pressure building into SW Oregon with southerly gradients across Western Oregon. Valley winds were ssw at 5-15 mph. The winds should veer to northwesterly this afternoon, as the surface high pressure ridge builds northward in the wake of the exiting upper-level trough. Skies will clear tonight with areas of ground fog likely forming due to the damp conditions. Surface Winds: SSW 5-15 this morning, WNW 5-15 this afternoon. Transport Winds: SW 20 this morning, W 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 70. High Temperature: Salem\'s high temperature today will be near 70. Humidities: Minimum relative humidity will be near 57%. Sunrise/Sunset: Salem sunset tonight: 8:07pm; sunrise tomorrow: 6:23am. Extended Outlook: A flat transitory ridge of high pressure will continue to dry and warm the air mass Friday with surface winds becoming northerly. The ridge will move over Montana Saturday, with the flow aloft over Oregon turning southwesterly, in response to a large upper-level trough approaching from the Gulf of Alaska. Temperatures will continue to warm with sunny skies allowing for further drying of damp fields. The computer forecast models are becoming consistent in moving the upper-level trough closer to the coastline Sunday with increasing southwesterly flow aloft. An unseasonably strong jet stream will likely drive another fairly potent weather system onshore Sunday night with more rain spreading across the Willamette Valley. Rainfall totals will likely range from one-tenth to one-quarter of an inch, by Monday morning, with locally greater amounts in the north valley. The flow aloft is forecast to become northwesterly Tuesday and Wednesday with weak upper-level troughs maintaining a slight chance of showers...especially in the north. Strong onshore flow will keep temperatures below normal. The jet stream may push northward enough Thursday to decrease the onshore flow and dry things out. That would enable temperatures to recover close to normal. Tomorrow (22 Aug): Patchy Morning Fog...Mostly Sunny & Warmer. Wind: N 5-15. 50/80 Sat (23 Aug): Sunny and Warm. 52/85 Sun (24 Aug): Mostly Sunny. Increasing Clouds with a Chance of Rain Late. 54/82 Mon (25 Aug): Rain Likely...Turning to Showers by Afternoon. Much Cooler. 58/72 Tue (26 Aug): Mostly Cloudy North...Slight Chance of Showers. Partly Cloudy South. 52/74 Wed (27 Aug): Mostly Cloudy North...Slight Chance of Showers. Partly Cloudy South. 52/74 Thu (28 Aug): Mostly Sunny. 50/78 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 22 07:59:46 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 22 Aug 2008 09:59:46 -0500 Subject: [willamette-fcst] Forecast - Friday, August 22nd, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 22nd, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 7:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Showers tapered off early on Thursday across Western Oregon, with the flow aloft turning northwesterly, in the wake of a strong upper-level trough that brought soaking rains to the Willamette Valley Tuesday and Wednesday. Rainfall amounts in the 24 hours ending at 5am today were generlaly less than one-tenth of an inch across the valley. With some sunbreaks Thursday afternoon, valley high temperatures reached the low 70s, after staying in the upper 60s Wednesday. Relative humidties dropped below 50% Thursday afternoon in the valley, which aided the drying of damp fields. The ODA surface analysis showed high pressure centered over NE Oregon and a weak thermal low pressure trough building northward into Western Oregon. Gradients were weak north-northeasterly across the Willamette Valley with surface winds light and variable at mid-morning. Clearing skies overnight allowed temperatures to drop into the mid to upper 40s across much of the valley this morning with areas of ground fog. Mid-morning temperatures had recovered into the mid to upper 50s. A flat upper-level ridge of high pressure was moving over the region this morning. The Salem sounding showed considerable warming and drying aloft since Thursday morning. Satellite imagery showed both low and mid-level clouds over the Willamette Valley with some breaks in the overcast. Fields will get an opportunity to further dry out today, as the air mass continues to warm up and dry out. Skies will become mostly sunny this afternoon with northerly winds and lower humidities. Afternoon highs should reach 80 degrees, which is about normal for late August. Surface Winds: Var 3-8 this morning, N 5-15 this afternoon. Transport Winds: NE 14 this morning, NNE 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 56. High Temperature: Salem\'s high temperature today will be near 80. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 33%. Sunrise/Sunset: Salem sunset tonight: 8:06pm; sunrise tomorrow: 6:24am. Extended Outlook: The ridge will move over Montana Saturday, with increasing southwesterly flow aloft over Oregon. Valley temperatures should warm into the mid 80s under mostly sunny skies. The southwesterly flow aloft is forecast to further strengthen Sunday, as a broad upper-level trough in the Gulf of Alaska slowly shifts eastard. Rain from a fairly active cold front is forecast to move onto the Washington Coast Sunday afternoon and slowly sag south and east into the Willamette Valley Sunday night and Monday. Rainfall totals from this system will likely range from one-tenth to one-quarter of an inch, with locally greater amounts, near the Cascade foothills, in the north. Showers will taper off Monday night with the flow aloft is becoming northwesterly. The latest computer forecast guidance is suggesting that a building ridge of high pressure will shift the jet stream north into Southern British Columbia Tuesday through Friday, of next week, with dry and warmer weather returning to Oregon. Surface winds are forecast to be mostly northerly. Tomorrow (23 Aug): Sunny and Warm. 52/85 Sun (24 Aug): Increasing Clouds with a Chance of Rain Late. 54/82 Mon (25 Aug): Rain Likely...Turning to Showers by Afternoon. Much Cooler. 58/72 Tue (26 Aug): Becoming Mostly Sunny. 49/76 Wed (27 Aug): Sunny and Warmer. 49/81 Thu (28 Aug): Sunny and Warm. 52/84 Fri (29 Aug): Sunny and Warm. 54/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 25 07:54:38 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 25 Aug 2008 09:54:38 -0500 Subject: [willamette-fcst] Forecast - Monday, August 25th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, August 25th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: After a warm weekend, with valley highs Saturday in the mid to upper 80s and Sunday in the low 80s, another moist cold front spread rain into the Willamette Valley late Sunday afternoon. The slow moving front cold front dumped between one-quarter and two-thirds of an inch of rain across the valley by 5am this morning. The clouds and rain held valley temperatures up overnight with minimums in the mid to upper 50s. The soundings from Salem on Sunday showed a large tongue of warm air aloft capping mixing heights below 2000 feet all day. The sounding from this morning showed considerable cooling from the surface all the way up to 25,000 feet. That will make for higher mixing heights today, but relative humidtiy levels will stay over 60% for most of the day and fields are wet. The ODA surface analysis showed high pressure across Western Washington and Western Oregon with onshore flow west of the cold front that was moving into Eastern Oregon. Satellite imagery showed the leading edge of the clouds from the cold front reaching Union County in NE Oregon and stretching southeastward into northern Klamath County, in South-Central Oregon. The back edge of the solid clouds had moved across the western side of the Willamette Valley, where some patches of blue sky were breaking through. An upper-level trough will further chill the air aloft today and keep a few showers going across Western Oregon. With strong onshore flow and cold air aloft, valley high temperatures should stay in the upper 60s (normal for today is 80 degrees). The upper-level trough will slide east of the Cascades this evening with the flow aloft becoming northwesterly and drying out. That will help skies to clear overnight, which will allow most valley temperatures to drop into the 40s. With high humidity levels near the surface, areas of fog and low clouds are likely by Tuesday morning. Surface Winds: NW 5-10 this morning, NW 8-15 this afternoon. Transport Winds: NW 10 this morning, NW 13 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 59. High Temperature: Salem\'s high temperature today will be near 68. Humidities: Minimum relative humidity will be near 57%. Sunrise/Sunset: Salem sunset tonight: 8:01pm; sunrise tomorrow: 6:28am. Extended Outlook: A flat ridge of high pressure will continue the northwesterly flow aloft Tuesday. Surface winds across the valley will turn northerly with slow drying and warming of the air mass across Western Oregon. A weak cold front is forecast to slide across Southern British Columbia and Western Washington Wednesday. The southern edge of this system may be strong enough to to bring some drizzle fromt he north coast to the extreme Northern Willamette Valley. Transport winds may back from northerly to northwesterly Wednesday, especially in the north valley. That would normally present a possible burning opportunity for the north valley, but fields may be too damp from the recent rains. Weak ridging aloft will dry the air mass Thursday with transport winds likely turning northerly again. Another weather system is forecast to swing into Southern British Columbia and NW Washington Friday afternoon. The flow aloft is forecast to become more westerly over Oregon, in response to an approaching weak upper-level trough. Transport winds and mixing heights could become favorable for open burning of dry fields. The upper-level trough is forecast to move over the region Saturday with increasing onshore flow cooling valley temperatures back into the 70s. Some morning drizle is possible...especially along the coast. A flat transitory ridge will turn the flow aloft northwesterly Sunday, for drier and warmer weather. The ridge if forecast to shift east of the region Monday with the flow aloft becoming southwesterly. A cold front is forecast to approach the coast late Monday, but that is getting too far out for the forecast models to time accurately. Tue (26 Aug): Areas of Morning Fog and Low Clouds...Mostly Sunny in the Afternoon. 47/76 Wed (27 Aug): Partly Sunny. Slight Chance of Sprinkles or Drizzle North. 48/78 Thu (28 Aug): Sunny and Warmer. 48/83 Fri (29 Aug): Mostly Sunny. Increasing High Clouds. 52/82 Sat (30 Aug): Morning Clouds. Afternoon Clearing. 53/76 Sun (31 Aug): Mostly Sunny. 50/80 Mon (01 Sep): Mostly Sunny. Increasing Clouds late. 51/78 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Aug 26 07:48:59 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 26 Aug 2008 09:48:59 -0500 Subject: [willamette-fcst] Forecast - Tuesday, August 26th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Tuesday, August 26th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 7:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: An upper-level trough combined with daytime heating to trigger a few afternoon showers Monday...mainly over the north valley. Skies cleared overnight, allowing temperatures to drop into the 40s and low 50s across most of Western Oregon. Cool temperatures and the moist ground helped areas of fog to form...mainly in the southern Willamette Valley, near Eugene, and along the coast. Visible satellite imagery showed only patchy low clouds over Western Oregon. The Salem sounding this morning showed more cooling, from the surface to about 7500 feet, with warming above 7500 feet. Low-level northeasterly winds, from just above the surface throught 3000 feet, were helping to dry out the air mass. The ODA surface analysis showed high pressure centers over Western Oregon, Western Washington, and Eastern Oregon with very weak pressure gradients across the Willamette Valley. A flat ridge of high pressure will give northwesterly flow aloft to the region today. Transport winds over the valley will turn northerly this afternoon, as a thermal trough attempts to build northward into SW Oregon. The north winds will drop humidities to near 30% this afternoon, which will aid in the drying of damp fields. The air aloft is still quite cool for late August, so even with ample sunshine today, afternoon temperatures will remain below normal...in the mid 70s. A weather system is forecast to move across Southern British Columbia tonight with the trailing edge of the cold front increasing the onshore flow across NW Oregon. Some Drizzle or very light rain is possible along the North Oregon Coast and in the Northern Willamette Valley Wednesday morning, but skies should clear Wednesday afternoon, as high pressure rebuilds over the region. Surface Winds: NW 3-6 this morning, N 5-15 this afternoon. Transport Winds: NNE 5 this morning, N 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 45. High Temperature: Salem\'s high temperature today will be near 76. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 32%. Sunrise/Sunset: Salem sunset tonight: 7:59pm; sunrise tomorrow: 6:29am. Extended Outlook: Flat ridging aloft will dry the air mass Thursday with transport winds likely turning northerly. A stronger upper-level trough is forecast to approach the coastline Friday afternoon with the flow aloft becoming southwesterly. Transport winds and mixing heights could become favorable Friday afternoon for open burning of dry fields. The upper-level trough is forecast to move over the region Saturday with increasing onshore flow cooling valley temperatures back into the 70s. Some morning drizzle is possible...especially along the coast. The flow aloft is forecast to become northwesterly Sunday with surface and transport winds likely turning northerly and drying the air mass. Weak southwesterly flow aloft is forecast for early next week with near-normal temperatures. All of the long-range models are indicating a possible burning opportunity, sometime between Tuesday and Thursday of next week, as the flow aloft becomes southwesterly and induces increasing onshore flow. Tomorrow (27 Aug): AM Clouds...Slight Chance Drizzle North. Afternoon Clearing. 51/76 Thu (28 Aug): Mostly Sunny and Warmer. 50/83 Fri (29 Aug): Mostly Sunny. Increasing High Clouds Late. 53/83 Sat (30 Aug): Morning Clouds. Afternoon Clearing and Cooler. 55/75 Sun (31 Aug): Becoming Mostly Sunny. 49/76 Mon (01 Sep): Mostly Sunny. 49/81 Tue (02 Sep): Mostly Sunny. 50/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 27 07:58:21 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 27 Aug 2008 09:58:21 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 27th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 27th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 7:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed from 12:00pm until 7:00pm. Weather Discussion: A moist Pacific storm system brought a soaking rain to northwest Washington overnight with the northern Washington Coast getting over an inch of rain. More than one-quarter of an inch of rain fell, from Olympia northward, across the interior of Western Washington. The trailing cold front brought light rain to the northern Oregon Coast with areas of very light rain and drizzle falling early this morning in the northern Willamette Valley. Almost one-quarter of an inch of rain fell overnight at Astoria. The Portland Airport picked up .01 inches in the pre-dawn hours this morning with only trace amounts reported south of Portland to Eugene. The cold front was weakening and moving trough the northern Willamette Valley at mid-morning. Surface winds had shifted from southerly to southwesterly along the north coast and in the Portland area...in the immediate wake of the front. Doppler radar was showing very light rainfall from SW Washington to the northern Oregon Coast and over the northern coastal range. Another area of light rain was showing up over the northern Cascade foothills, with local upslope conditions enhancing the frontal precipitation. Radar also showed showers over extreme north-central and NE Oregon. Satellite imagery this morning showed mostly cloudy skies across the northern half of Oregon and mostly sunny skies over southern Oregon. The cold front will fall apart as it pushes east of the Cascades this afternoon. Northwesterly flow aloft will slowly clear skies over Western Oregon this afternoon, but temperatures will only climb into the low to mid 70s across the Willamette Valley. Relative humidties should drop below 45% this afternoon, which will aid in the drying of damp fields throughout the valley. The jet stream will migrate northward overnight, to over Southern British Columbia. A warm front will spread more clouds across Western Washington and the northern Willamette Valley, but no precipitation is expected east of the north coastal range. Skies should continue to clear overnight across the south valley. Overnight temperatures should be near normal with lows in the low to mid 50s. Surface Winds: S 5-12 this morning, NW 5-12 this afternoon. Transport Winds: SW 12 this morning, WNW 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5000 feet. Ventilation index 60. High Temperature: Salem\'s high temperature today will be near 74. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 7:57pm; sunrise tomorrow: 6:30am. Extended Outlook: Flat ridging aloft will send the storm track into Canada and dry the air mass over Oregon Thursday with transport winds turning northerly. A stronger upper-level trough is forecast to approach the coastline Friday afternoon with the flow aloft becoming southwesterly. That will warm valley temperatures well into the 80s with mostly sunny skies. Transport winds are forecast to back from northerly to northwesterly Friday afternoon with high mixing heights ahead of the approaching weather system. That may create a burning opportunity...especially for the north valley. Mechanical fluffing of damp fields is required, if you plan to take advantage of the potential Friday afternoon burning opportunity. A strong upper-level trough is forecast to move over the region Saturday with increasing onshore flow cooling valley temperatures back into the 70s. Some drizzle is possible...especially along the coast and over the north valley. The upper-level trough will push east of the region with the flow aloft turning northwesterly Sunday afternoon. That will begin to clear skies with trasport winds turning northerly. A transitory ridge is forecast for Monday with temperatures recovering to near normal. Another weather system is forecast for Tuesday, which could create a burning opportunity, if it holds off until late in the day. An upper-level trough will bring a chance of showers early Wednesday with a stronger ridge of high pressure building over the region beginning Wednesday afternoon. Tomorrow (28 Aug): Mostly Sunny and Warmer. 53/83 Fri (29 Aug): Mostly Sunny. Increasing High Clouds Late. 55/83 Sat (30 Aug): Mostly Cloudy and Much Cooler. Chance of Drizzle. 55/72 Sun (31 Aug): Morning Clouds. Chance of Drizzle. Afternoon Clearing. 50/74 Mon (01 Sep): Mostly Sunny. 48/77 Tue (02 Sep): Increasing Clouds. Chance of Showers Late...Mainly North. 49/77 Wed (03 Sep): Chance of Showers Early...Afternoon Clearing. 53/74 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Aug 28 08:04:10 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 28 Aug 2008 10:04:10 -0500 Subject: [willamette-fcst] Forecast - Thursday, August 28th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, August 28th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 2:00pm until 7:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A west-to-east oriented cold front unexpectedly stalled and weakened right across the northern Willamette Valley Wednesday afternoon. That created excellent ventilation conditions over the valley and allowed for the burning of some dry fields. High pressure began building into Western Oregon Wednesday evening...warming the air aloft with a sinking northwesterly flow. That cleared skies overnight and allowed temperatures to drop into the upper 40s and low 50s this morning. The Salem sounding this morning showed strong northwesterly flow aloft and considerble warming above 3000 feet. That will keep mixing heights from climbing above 3000 feet until about 2pm, with maximum mixing heights today only 3-4000 feet. The ODA surface analysis showed high pressure centers over both the Willamette Valley and East-Central Oregon with very weak pressure gradients over the Willamette Valley. Much of the valley had calm winds this morning. In response to a flat ridge of high pressure building over Oregon, the jet stream migrated northward across southern Canada overnight. A warm front was bringing some light rain to the Washinton Coast and the interior of NW Washington this morning. Satellite imagery showed cloudy skies across all of Western Washington and extreme NW Oregon (from Astoria to Portland). The remainder of Oregon had mostly clear skies. Precipitation is forecast stay north of the Oregon border today, except for possibly along the extreme north Oregon Coast. Some clouds will likely persist in the extreme north valley today, while the south valley enjoys a full day of sunshine. Temperatures will range from the upper 70s in the Portland area to the mid 80s in the south valley near Eugene. Transport winds were light northerly this morning and should increase, from the north, this afternoon, as the upper-level ridge axis moves directly over Western Oregon. The ridge is forecast to shift east of the Cascades overnight with the flow aloft becoming west-southwesterly by Friday morning. Surface Winds: Var 0-5 this morning, N 10 this afternoon. Transport Winds: N 5 this morning, N 13 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 52. High Temperature: Salem\'s high temperature today will be near 82. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 41%. Sunrise/Sunset: Salem sunset tonight: 7:55pm; sunrise tomorrow: 6:31am. Extended Outlook: An upper-level trough is forecast to approach the coastline Friday afternoon with the flow aloft becoming southwesterly. Valley temperatures should start off warmer than today but get capped in the low to mid 80s by increasing onshore flow in the afternoon. The increasing onshore flow should back the transport winds from northerly to northwesterly Friday afternoon...especially in the north valley, with cooling aloft leading to higher mixing heights than we will have today. It is likely that the combination of northwesterly transport winds and 4000-foot-plus mixing heights will provide a burning opportunity for dry north valley fields. Transport winds may stay too northerly to allow for burning in the south valley. Mechanical fluffing of damp fields is required, if you plan to take advantage of the potential Friday afternoon burning opportunity. A strong upper-level trough is forecast to move over the region Saturday with increasing onshore flow cooling valley temperatures back into the 70s. Some drizzle is possible...especially along the coast and over the north valley. The upper-level trough is forecast to remain over the region through Sunday for mostly cloudy and cool condtions with a chance of light showers. The trough is forecast to push east of the region Monday with the flow aloft turning northwesterly That will begin to clear skies and warm temperatures, with transport winds turning northerly. A weak weather system is forecast, in the northwesterly flow aloft, for Tuesday, which could create a burning opportunity. An upper-level ridge of high pressure will likely begin building over the region Wednesday, which could last through the remainder of next week. Tomorrow (29 Aug): Mostly Sunny. Increasing High Clouds Late. 53/82 Sat (30 Aug): Mostly Cloudy and Much Cooler. Chance of Drizzle or Light Showers. 55/70 Sun (31 Aug): Mostly Cloudy and Cool. Chance of Drizzle or Light Showers. 48/69 Mon (01 Sep): Becoming Mostly Sunny and Warmer. 47/76 Tue (02 Sep): Increasing Clouds. Slight Chance of Showers North. 49/77 Wed (03 Sep): Patchy Morning Clouds. Mostly Sunny and Warmer. 50/79 Thu (04 Sep): Sunny and Warmer. 50/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 29 08:03:32 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 29 Aug 2008 10:03:32 -0500 Subject: [willamette-fcst] Forecast - Friday, August 29th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 29th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is allowed from 12:00pm until 2:00pm with a 100 acre limit. Propane flaming is allowed from 12:00pm until 5:00pm. Stack burning is not allowed. Weather Discussion: Light westerly flow aloft prevailed over Oregon this morning, with a flat ridge of high pressure sliding across the state. The area of clouds and light rain that was over Western Washington most of Thursday had retreated northward with rainfall confined to the northern Washington Coast and near the Candian border across the interior of Western Washington. Skies were fair overnight in the interior of Western Oregon. Dew-point temperatures are quite high (low 60s) this morning across Western Oregon, most likely aided by evaporation from the early-week rainfall. Visible satellite imagery and surface reports show areas of low clouds and fog forming across the Willamette Valley. With daytime heating and a lack of onshore flow across the valley, the low clouds and fog should evaporate by late this morning. The ODA surface analysis showed a weak thermal trough of low pressure centered near Salem with weak pressure gradients over the Willamette Valley. The coastline had very light onshore flow with low clouds and fog. Infrared satellite imagery showed a band of clouds, associated with a cold front, stretching from Vancouver Island, British Columbia southwestward to about 300 miles off the northern Oregon Coast. An upper-level trough is forecast to approach the coastline this afternoon with the flow aloft becoming southwesterly. Valley temperatures should start off warmer than on Thursday but get capped in the low to mid 80s by increasing onshore flow in the afternoon. The increasing onshore flow should back the transport winds from north-northeasterly to northwesterly early this afternoon in the north valley and by late this afternoon in the south valley. Cooling aloft will help mixing heights approach 5000 feet later this afternoon. An open burning opportunity is likely for the north valley this afternoon, and there is a good chance that transport winds will turn enough northwesterly, later in the afternoon, for open burning in the south valley. Increasing low-level onshore winds may act to inhibit smoke plume development by late in the afternoon. The cold front will likely spread light rain onto the northern Oregon Coast by around 5pm with a chance of light rain in the Willamette Valley this evening. The cold front should pass through the valley by midnight with the threat of rain decreasind, but skies should remain mostly cloudy with strong onshore flow. Surface Winds: N 5 this morning, NW 5-15 this afternoon. Transport Winds: NNE 12 this morning, NW 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4900 feet. Ventilation index 59. High Temperature: Salem\'s high temperature today will be near 82. Humidities: Relative humidity drops to 50% by 3pm. Minimum relative humidity will be near 46%. Sunrise/Sunset: Salem sunset tonight: 7:53pm; sunrise tomorrow: 6:33am. Extended Outlook: A cold but fairly dry upper-level trough is forecast to move over the region Saturday and Sunday with increasing onshore flow cooling valley temperatures back into the 70s. Some drizzle is possible...especially along the coast. This system will bring a lot oc clouds to the region but not a lot of rainfall. It will be unseasonably cold in the mountains with the snow level possibly dropping as low as 5000 feet by Sunday morning. There will be scattered showers over the mountains this weekend but only a chance of showers over the Willamette Valley. The trough is forecast to push east of the region Monday with the flow aloft turning northwesterly That will begin to clear skies and warm temperatures, with transport winds turning northerly. A weak weather system, in the northwesterly flow aloft, could create a burning opportunity Tuesday...especially for the north valley. There is only a slight chance of showers for the north valley associated with this system. An upper-level ridge of high pressure is forecast to begin building over the region Wednesday and will likely last for the remainder of next week. Transport winds may turn strongly offshore by Thursday, which would allow for the burning of remaining fields on the west side of the valley. Sat (30 Aug): Mostly Cloudy and Much Cooler. Chance of Drizzle or Light Showers. 55/69 Sun (31 Aug): Mostly Cloudy and Cool. Chance of Drizzle or Light Showers. 46/69 Mon (01 Sep): Becoming Mostly Sunny. A Little Warmer after a Cool Start. 45/74 Tue (02 Sep): Partly Sunny. Slight Chance of a Light Shower North. 49/75 Wed (03 Sep): Sunny. North Winds. 50/78 Thu (04 Sep): Sunny and Warmer. NE Winds. 50/80 Fri (05 Sep): Sunny. NE Winds. 51/82 ODA Meteorologist weather at oda.state.or.us