From willamette-fcst at listsmart.osl.state.or.us Tue Sep 2 07:57:10 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 02 Sep 2008 09:57:10 -0500 Subject: [willamette-fcst] Forecast - Tuesday, September 2nd, 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, September 2nd, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 7:00pm. 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: A cool but fairly dry upper-level trough moved over the Pacific Northwest during the Labor Day Weekend and brought well below normal temperatures to Western Oregon. Valley highs Saturday cooled to near 70 degrees and stayed in the 60s Sunday. The trough did produce afternoon thundershowers Sunday with locally brief heavy rain. Most of the valley picked up one-tenth of an inch or less, but some local areas got hit with over one-third of an inch. The trough moved east Monday with a transitory ridge bringing dry and continued cool northwesterly flow aloft to the state. High temperatures warmed a few degrees from Sunday but stayed mostly in the upper 60s. Dry conditions, with fairly low afternoon humidities, allowed for the drying of any damp fields from the shower activity Sunday. A weak upper-level disturbance, in the northwesterly flow aloft, was moving onshore this morning and spreading some middle and high clouds across mainly the northern half of Oregon. Radar and surface reports were not indicating any precipitation associated wtih this system. Willamette Valley minimums were mostly in the mid 40s early this morning with mid-morning temperatures near 50 degrees. The Salem sounding this morning showed several degrees of warming aloft since Monday morning with a subsidence inversion at 3000 feet. Below the inversion, winds were from the NNE at about 10 mph. A little cooling aloft, associated the the passing of the upper-level disturbance, should combine with daytime heating to break the inversion and lift mixing heights to near 5000 feet later this afternoon. However, forecast northerly transport winds will significantly limit any burning opportunities...especially in the south valley. The ODA surface analysis showed very weak northerly gradients across Western Oregon this morning with a weak thermal trough trying to build northward along the extreme south coast. Winds should stay northerly and increase this afternoon in the south valley. It is possible that the upper-level disturbance will be strong enough to turn the transport winds north-northwesterly in the north valley this afternoon. Valley temperatures will remain below normal today but recover a few degrees from Monday with high reaching into the mid 70s. A ridge is forecast to begin building into the west coast this evening with the northwesterly flow aloft drying out. That should help to clear skies and allow overnight temperatures to drop back into the mid 40s across the valley. Surface Winds: N 5-10 this morning, NW 5-10 north valley...N 5-15 south valley this afternoon. Transport Winds: NNE 12 this morning, NNW 10 north valley...N 15 south valley 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 75. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 35%. Sunrise/Sunset: Salem sunset tonight: 7:46pm; sunrise tomorrow: 6:37am. Extended Outlook: The dry northwesterly flow aloft will bring sunny skies and warmer temperatures to Western Oregon Wednesday with northerly transport winds across the Willamette Valley. The upper-level ridge axis is forecast to stay offshore, but it may build close enough to the coastline for transport winds to turn north-northeasterly Thursday and/or Friday. That may allow for the burning of the remaining fields on the west side of the valley. A weak upper-level disturbance is forecast to move over the top of the offshore ridge and drop southward to near the Washington/Canadian border Saturday. That should continue the dry northwesterly flow aloft with little change in temperatures. The ridge is forecast to build a little closer the the coastline Sunday for a few degrees of warming. Another weak system is forecast to flatten the upper-level ridge a little Monday and Tuesday with the flow aloft becoming more westerly. A few clouds may make it though the ridge, but no precipitation is forecast. Temperatures will likely cool a few degrees. This system may create a limited burning opportunity for the north valley, but a significant burning opportunity is not apparent at this time. Tomorrow (03 Sep): Sunny. North Winds. 45/78 Thu (04 Sep): Sunny and a Little Warmer. NNE Winds. 47/80 Fri (05 Sep): Sunny. NNE Winds. 50/83 Sat (06 Sep): Sunny. 50/83 Sun (07 Sep): Sunny. 51/86 Mon (08 Sep): Mostly Sunny. 51/83 Tue (09 Sep): Mostly Sunny. 51/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Sep 3 08:03:49 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 03 Sep 2008 10:03:49 -0500 Subject: [willamette-fcst] Forecast - Wednesday, September 3rd, 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, September 3rd, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 3:00pm. Preparatory burning is allowed from 12:00pm until 3:00pm with a 100 acre limit. Propane flaming is allowed from 12:00pm until 3:00pm. Stack burning is not allowed. Weather Discussion: A building ridge of high pressure offshore was producing a dry northwesterly flow aloft over Oregon this morning. The ODA surface analysis continued to show very weak northerly gradients across Western Oregon this morning with a flat thermal trough trying to build northward along the extreme south coast. Visible satellite imagery showed low clouds along the extreme north coast...making their way up the Columbia River into the Portland area. The remainder of Oregon had mostly clear skies. It was a cool morning with valley minimums generally in the low to middle 40s. The Salem sounding this morning showed warming, above 4500 feet, compared to Tuesday morning, as a result of sinking air associated with the building upper-level ridge. That will yield lower mixing heights today (maximum of just 4500 feet) and warmer surface temperatures. Willamette Valley highs were in the mid to upper 70s Tuesday and should reach the upper 70s to low 80s today. Transport winds were north-northeasterly this morning and are forecast to be northerly this afternoon. That makes open burning unlikey again this afternoon. However, we will monitor the winds, with pibals, this afternoon for the slight chance of a turn to the northwest...especially in the north valley. Low relative humidity levels and increasing northerly winds may result in sections of the valley meeting State Fire Marshal Conditions later this afternoon...especially south. Dry northwesterly flow will continue overnight with mostly clear skies across the valley. That will allow temperatures to dip back into the 40s, by Thursday morning, over much of the valley. Surface Winds: N 5-10 this morning, NW 5-15 north valley...N 8-18 south valley this afternoon. Transport Winds: NNE 10 this morning, N 10-15 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 79. Humidities: Minimum relative humidity will be near 29%. Sunrise/Sunset: Salem sunset tonight: 7:44pm; sunrise tomorrow: 6:38am. Extended Outlook: A dry weather pattern is forecast for the duration of the extended forecast period...and beyond...possibly through the first half of September. That is consistent with the ODA long-range climate prediction of a drier than normal September, for all of Oregon, based on analog years with similar tropical ocean temperature profiles. The upper-level ridge is forecast build closer to the coastline Thursday and Friday, which would further warm temperatures and eventually turn the transport winds northeasterly. That may allow for the burning of the remaining fields on the west side of the valley. The best opportunity for that appears to be Friday. Other open burning is highly unlikely for the rest of this week. A weak upper-level disturbance is forecast to move over the top of the offshore ridge and drop southward to near the Idaho/Canadian border Saturday. That should cool the air aloft slightly with continued northwesterly flow. Surface temperatures will likely be similar to Friday with continued sunny skies. The ridge is forecast rebuild over Oregon Sunday with tempertures warming up a few degrees. Another system is forecast to flatten the upper-level ridge Monday and Tuesday with the flow aloft becoming more westerly. A few clouds may make it though the ridge, but no precipitation is forecast. Temperatures will likely cool a few degrees. This system may create a burning opportunity early next week...especially for the north valley. Tomorrow (04 Sep): Sunny. North Winds. 47/79 Fri (05 Sep): Sunny. NE Winds. 39/83 Sat (06 Sep): Sunny. 50/83 Sun (07 Sep): Sunny and Warmer. 52/87 Mon (08 Sep): Mostly Sunny. Increasing onshore flow in the afternoon. 52/84 Tue (09 Sep): Mostly Sunny. N-NW winds. 50/79 Wed (10 Sep): Sunny. 49/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 4 08:02:08 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 04 Sep 2008 10:02:08 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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: Thursday, September 4th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 7:00pm. 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 strong upper-level ridge offshore will continue a dry northwesterly flow aloft over Oregon today. Satellite imagery this morning showed only patchy low clouds from the north coast to the extreme northern Willamette Valley with areas of high clouds over the remainder of the state. The ODA surface analysis showed high pressure offshore extending into Western Washington and NW Oregon with a thermal trough beginning to push northward, from California, into extreme SW Oregon. The Salem sounding this morning showed northeasterly low-level winds and more warming aloft since Wednesday. That will yield slightly lower mixing heights today (maximum near 4000 feet) and warmer surface temperatures. Willamette Valley highs should be near 80 degrees this afternoon. Low relative humidity levels and increasing northerly winds pushed the south valley into State Fire Marshal conditions late Wednesday afternoon. Dew-point temperatures are about 10 degrees higher this morning, across the valley, so relative humidtiy levels will not likely dip as low as 30% today. However, transport winds are forecast to be north-northeasterly this afternoon, which makes open burning unlikely. Dry northwesterly flow will continue overnight with mostly clear skies. Slow warming aloft will help keep overnight temperatures from falling much below normal. Friday morning minimums should be in the mid to upper 40s across the valley. Surface Winds: N 5-10 this morning, N 8-18 this afternoon. Transport Winds: NE 10 this morning, NNE 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 80. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 33%. Sunrise/Sunset: Salem sunset tonight: 7:43pm; sunrise tomorrow: 6:40am. Extended Outlook: The dry weather pattern is forecast to continue during the extended forecast period and possibly through the first half of September. That is consistent with the ODA long-range climate prediction of a drier than normal September. The ODA Seasonal Climate Forecast is updated monthly, on our website, at: http://oregon.gov/ODA/NRD/weather.shtml#Weather_forecasts. The upper-level ridge is forecast build closer to the coastline Friday with temperatures continuing to slowly warm over Oregon. Transport winds should take on more of an offshore component, which may allow for the burning of remaining fields on the west side of the valley. Other open burning is highly unlikely. A weak weather system is still forecast to ride over the top of the ridge and drop the near the Idaho/Canadian border Saturday afternoon. That will act to turn transport winds form offshore to northerly and perhaps cool temperatures a degree or two. The ridge is forecast to rebuild Sunday with the flow aloft warming and turning northerly. With sunny skies and tranport winds forecast to turn offshore, in response to a thermal trough building into SW Oregon, valley temperatures may warm into the mid and upper 80s. The ridge is forecast to flatten Monday and Tuesday with the flow aloft becoming more westerly. A few clouds may make it though the ridge, but no precipitation is forecast. Temperatures will likely cool close to normal, as the thermal trough slides east of the Cascades and onshore flow develops across Western Oregon. Depending on timing, this transition may create a burning opportunity Monday afternooon and/or Tuesday of next week. The upper-level ridge is forecast to rebuild over Oregon, beginning Wednesday, with temperatures shooting back above normal and transport winds becoming northerly again. The ridge may build over the region enough by Thursday for offshore flow to develop, which would maintain sunny conditions with even warmer temperatures. Tomorrow (05 Sep): Sunny. NE Winds. 49/83 Sat (06 Sep): Sunny. 51/82 Sun (07 Sep): Sunny and Warmer. 53/87 Mon (08 Sep): Mostly Sunny. Increasing onshore flow in the afternoon. 52/83 Tue (09 Sep): Partly Cloudy with onshore flow. Slight chance of a shower north. 50/75 Wed (10 Sep): Mostly Sunny. Winds becoming northerly. 49/77 Thu (11 Sep): Sunny and Warm. 49/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Sep 5 07:59:17 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 05 Sep 2008 09:59:17 -0500 Subject: [willamette-fcst] Forecast - Friday, September 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. Issued: Friday, September 5th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 2:00pm. Preparatory burning is allowed from 12:00pm until 2:00pm with a 100 acre limit. Propane flaming is allowed from 12:00pm until 2:00pm. Stack burning is not allowed. Weather Discussion: A strong upper-level ridge offshore will move closer to the coastline today and continue the dry northwesterly flow aloft over Oregon. Satellite imagery showed high clouds circulating clockwise over the ridge, across Washington...then southeastward over much of Eastern Oregon. Onshore flow had brought low clouds onto the Washington coast...extending southward to the central Oregon Coast. A few low clouds had managed to form, in the extreme northern Willamette Valley, along with patchy areas of fog. Otherwise, skies were mostly clear over the interior of Western Oregon and along the south coast. The ODA surface analysis showed a low-pressure trough over East-Central Washington with weak onshore flow across Western Washington. The flow turned northerly across Western Oregon, in response to a thermal trough of low-pressure building northward along the southern Oregon Coast. Valley winds were light northerly and strongest near Eugene. The Salem sounding this morning showed more warming aloft since Thursday, so mixing heights will be about 500-1000 feet lower today (maximum of about 3500 feet). Temperatures will continue their upward trend with afternoon highs in the low to mid 80s. Low relative humidity levels and increasing northerly winds pushed the south valley into State Fire Marshal conditions again late Thursday afternoon. The northerly winds should be even stronger today, and humidtiy levels may drop enough for areas of the valley to meet State Fire Marshal conditions by mid-afternoon. With the upper-level ridge buildng closer to the coastline today, transport winds should take on more of an offshore component. That may allow for the burning of remaining fields on the west side of the valley around midday. Other open burning is highly unlikely today. Surface Winds: N 5-15 G20 South this morning, N 12-22 G30 South this afternoon. Transport Winds: NNE 15 this morning, NNE 17 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 60. High Temperature: Salem\'s high temperature today will be near 83. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 29%. Sunrise/Sunset: Salem sunset tonight: 7:41pm; sunrise tomorrow: 6:41am. Extended Outlook: The dry weather pattern is forecast to continue during the extended forecast period and possibly through the first half of September. That is consistent with the ODA long-range climate prediction of a drier than normal September. The ODA Seasonal Climate Forecast is updated monthly, on our website, at: http://oregon.gov/ODA/NRD/weather.shtml#Weather_forecasts. A weak weather system is forecast to ride over the top of the offshore ridge and drop into Western Montana Saturday. That will hold the ridge in place with little change in temperatures across Western Oregon. The ridge is forecast to build over Oregon Sunday with a surface thermal trough building northward into SW Oregon. That will turn transport winds even more offshore with warming temperatures under sunny skies. The ridge is forecast to weaken, and shift more offshore, Monday and Tuesday. That will allow a couple of weather systems to slide over the ridge and drop closer the Pacific Northwest. The thermal trough may shift east of the Cascades Monday afternoon with onshore flow developing across the Willamette Valley. That process could be delayed until the second weather system moves north of the region Tuesday. Depending on the timing of these changes, there could be burning opportunities Monday afternooon and/or Tuesday of next week. The upper-level ridge is forecast to push back closer to the coastline Wednesday, with the flow aloft and transport winds becoming northerly. Temperatures will climb to normal. The ridge is forecast to build over the region Thursday and Friday for continued sunny and warm weather. Transport winds are forecast to turn offshore with well above normal temperatures. Tomorrow (06 Sep): Sunny. North winds. 51/83 Sun (07 Sep): Sunny and Warmer. NE winds. 53/87 Mon (08 Sep): Sunny. Onshore flow possibly increasing late. 53/84 Tue (09 Sep): Mostly Sunny. Cooler with onshore flow. 51/77 Wed (10 Sep): Mostly Sunny. Winds becoming northerly. 48/79 Thu (11 Sep): Sunny and Warm. 49/83 Fri (12 Sep): Sunny and Warm. 50/87 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Sep 8 08:02:57 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 08 Sep 2008 10:02:57 -0500 Subject: [willamette-fcst] Forecast - Monday, September 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: Monday, September 8th, 2008 at 9:00am. Burn Advisory: ...State Fire Marshal Conditions may be met this afternoon due to low humidities and increasing northerly winds... 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 sunny and very warm weather to Oregon over the weekend. Saturday had similar tempertures to Friday with Willamette Valley highs near 80 degrees. By Sunday, a building surface thermal trough, along the Oregon Coast, produced dry offshore winds across Western Oregon with valley temperatures approaching 90 degrees. The combination of brisk noth winds and very low relative humidities put the valley into State Firre Marshal conditions Sunday afternoon. The air mass remains very dry over Western Oregon this morning. Dew-point temperatures are only in the mid 40s, so realtive humidities will drop to 30%, when surface temperatures climb into the low 80s shortly after noon. North winds are expected to increase this afternoon, so much of the valley may meet Fire Marshal Conditions by early this afternoon. The ODA surface analysis showed a strong thermal trough extending northward along the length of the Oregon Coast and into extreme SW Washington. Pressure gradients remained offshore across Western Oregon, at mid-morning, with mostly calm winds in the valley and light easterly winds along the coast. Visible satellite imagery showed clear skies across Western Oregon. Eugene was reporting a few low clouds. The salem sounding this morning showed very warm air aloft. Mixing heights will stay below 3000 feet until mid-afternoon, when low humidity levels and increasing northerly winds may put much of the valley back into State Fire Marshal conditions. Transport winds were from the NE this morning, which may allow for the burning of remaining fields on the west side of the valley late this morning. Infrared satellite imagery showed a couple of cloud-bands moving across Vancouver Island at mid-morning. They are associated with a weak upper-level disturbance which is forecast to drop southeastward this afternoon across Northern Washington. That system will likely turn tranport winds from northeasterly to northerly this afternoon, across the Willamette Valley, with minor cooling aloft and strong surface heating combining to raise mixing heights over 5000 feet. However, open burning is unlikely today, because northerly surface and transport winds will likely combine with low humidities to send much of the valley into Fire Marshal conditions this afternoon. Valley temperatures will likely start out a few degrees warmer today but top out at about the same level as on Sunday due to the offshore flow becoming northerly. A little strong upper-level disturbance is forecast to approach the coastline overnight with the surface thermal trough shifting east of the Cascades. That should turn surface winds onshore overnight and significantly raise humidity levels in the Willamette Valley. Some marine clouds may form in the valley by Tuesday morning. Surface Winds: N 5-13 this morning, N 10-20 this afternoon. Transport Winds: NE 13 this morning, N 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5500 feet. Ventilation index 83. High Temperature: Salem\'s high temperature today will be near 89. Humidities: Minimum relative humidity will be near 23%. Sunrise/Sunset: Salem sunset tonight: 7:35pm; sunrise tomorrow: 6:44am. Extended Outlook: A weak upper-level trough is forecast to move across the Pacific Northwest Tuesday with increasing onshore flow at the surface. That will bring some patchy marine clouds into the valley and cool temperatures significantly. Transport wind are forecast to become northwesterly, especially in the north valley, which may create a burning opportunity. High pressure is forecast to begin building back over the region Wednesday with the flow aloft, and transport winds, becoming northerly. As the ridge move over the region Thursday, the tranport winds may turn offshore, for further warming and drying of the air mass. A weak upper-level disturbance is forecast to flatten the ridge and turn the flow weakly onshore Friday. That will bring another cool-down to the regin and a potential burning opportunity...especially for the north valley. The ridge is forecast to rebuild over the Pacific Northwest this weekend for continued sunny and warm weather. The ridge may push east of thre region by early next week with increasing southesterly flow aloft beginning a cooling trend. The weather pattern for next week still appears dry for Western Oregon but could create some burning opportunities...especially for the north valley. Tomorrow (09 Sep): Patchy AM Clouds...Sunny and Cooler. 50/78 Wed (10 Sep): Sunny. 46/80 Thu (11 Sep): Sunny and Warmer. 49/88 Fri (12 Sep): Mostly Sunny but Cooler. 52/81 Sat (13 Sep): Sunny. 50/83 Sun (14 Sep): Sunny and Warmer. 53/86 Mon (15 Sep): Mostly Sunny but Cooler. 51/80 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Sep 9 08:04:19 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 09 Sep 2008 10:04:19 -0500 Subject: [willamette-fcst] Forecast - Tuesday, September 9th, 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, September 9th, 2008 at 9:00am. Burn Advisory: ...State Fire Marshal conditions may locally be reached late this afternoon, mainly from Salem south, due to low relative humidities and increasing northwesterly winds... 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 2:00pm. Stack burning is not allowed. Weather Discussion: A weak upper-level trough is moved across NW Oregon early this morning. Infrared satellite imagery showed a band of middle and high clouds, associated with this system, stretching from Northern Idaho across NE and North-Central Oregon. The system will weaken as it pushes southeast across this remainder of Oregon this afternoon. A dry north-northwesterly flow aloft was moving in behind that system over NW Oregon, so skies will continue to be sunny today east of the coastal range. The upper-level trough was strong enough to kick the surface thermal trough east of the Cascades with onshore flow increasing across Western Oregon at mid-morning. The ODA surface analysis showed high pressure centered near the Central Oregon Coast with a weak thermal trough extending from Central Washington through South-Central Oregon. The onshore flow brought marine low clouds into the coastline overnight, but there was not much penetration east of the coastal range at mid-morning. Skies were mostly sunny in the western valleys. The air mass was still quite dry over Western Oregon early this morning with dew-point temperatures remaining in the 40s. However, over the past couple of hours, dew-point temperatures are beginning to rise, as the onshore flow increases. That may help the valley avoid Fire Marshal conditions this afternoon, as temperatures rise into the low 80s and northwesterly winds increase. The Salem sounding this morning showed considerable cooling aloft since Monday, so mixing heights should approach 3000 feet by noon and top out near 5000 feet this afternoon. The increasing onshore flow will likely create a burning opportunity, for north valley, this afternoon, as trasport winds become northwesterly. Another upper-level trough, currently over SE British Columbia, will slide to near NE Washington this evening. That should keep the upper-level ridge from rapidly building back over Western Oregon and maintain northwesterly transport winds across the Northern Willamette Valley through the afternoon. It is also possible that transport winds will turn enough northwesterly to allow for limited open burning in the south valley this afternoon. Surface Winds: NW 5-10 this morning, NW 8-16 this afternoon. Transport Winds: NNW 7 this morning, NW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4800 feet. Ventilation index 48. High Temperature: Salem\'s high temperature today will be near 82. Humidities: Minimum relative humidity will be near 30%. Sunrise/Sunset: Salem sunset tonight: 7:33pm; sunrise tomorrow: 6:46am. Extended Outlook: High pressure is forecast to begin building back over Western Oregon by Wednesday morning with the flow aloft becoming northerly and the air mass warming back up. Conditions may allow for the burning of the remaining west valley fields either Wednesday or Thursday morning, as the transport winds become increasingly offshore. Very dry conditions and northerly surface winds may put much of the valley back into Fire Marshal conditions in the afternoons. A weak upper-level disturbance is forecast to flatten the ridge and turn the flow weakly onshore Friday. That will bring another cool-down to the region and a potential burning opportunity, especially for the north valley. The strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. The ridge will slowly push east of the region early next week with increasing southwesterly flow aloft beginning a cooling trend. The weather pattern for next week still appears dry for Western Oregon, so there could be some burning opportunities...especially for the north valley. Tomorrow (10 Sep): Sunny and Warm. 46/84 Thu (11 Sep): Sunny and Warmer. 48/88 Fri (12 Sep): Mostly Sunny but Cooler with Onshore Flow. 52/80 Sat (13 Sep): Sunny and Warmer. 49/84 Sun (14 Sep): Sunny and Very Warmer. 53/90 Mon (15 Sep): Mostly Sunny and Very Warm. 53/88 Tue (16 Sep): Mostly Sunny and Cooler. 51/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Sep 10 08:04:32 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 10 Sep 2008 10:04:32 -0500 Subject: [willamette-fcst] Forecast - Wednesday, September 10th, 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, September 10th, 2008 at 9:00am. Burn Advisory: ...State Fire Marshal conditions may be reached, after 2:30pm, due to low humidities and increasing northerly winds... Agricultural burning is allowed. Suggested burn times are from 12:30pm until 2:30pm. Preparatory burning is allowed from 12:30pm until 2:30pm with a 100 acre limit. Propane flaming is allowed from 12:30pm until 2:30pm. Stack burning is not allowed. Weather Discussion: A weak upper-level disturbance moved across Northern Washington Tuesday evening and was over Northern Idaho this morning. That induced weak onshore flow Tuesday evening which brought cooler air into the Willamette Valley. However, the air mass remains very dry this morning with virtually no penetration of marine clouds into the interior of Western Oregon overnight. Clear skies allowed for a chilly morning with valley minimums dropping into the low 40s. The Salem sounding this morning also showed considerable cooling aloft since Tuesday, so mixing heights should climb to near 3000 feet by early afternoon, when surface temperatures reach the low 70s. Northeasterly transport winds may allow for the burning of remaining fields, on the west side of the valley, later this morning. Other open burning is highly unlikely today with north-northeasterly transport winds forecast for this afternoon. Skies should be sunny today with valley highs recovering into the low 80s. A building ridge of high pressure is turning the flow aloft northerly and keeping the air mass very dry over Western Oregon. The ODA surface analysis showed flat pressure gradients over Western Oregon this morning. However, a thermal trough is forecast to begin building into SW oregon this afternoon and increase the northerly gradients across the Willamette Valley. Low humidties and increasing northerly winds may push the Willamette Valley into State Fire Marshal conditions after about 2:30pm...especially south. Surface Winds: N 5-12 this morning, N 10-17 G25 south this afternoon. Transport Winds: NE 12 this morning, NNE 17 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4100 feet. Ventilation index 70. High Temperature: Salem\'s high temperature today will be near 82. Humidities: Minimum relative humidity will be near 27%. Sunrise/Sunset: Salem sunset tonight: 7:31pm; sunrise tomorrow: 6:47am. Extended Outlook: High pressure will push over Oregon Thursday with the air mass warming a few more degrees. That will lower mixing heights slightly with north-northeasterly transport winds making open burning unlikely. Very dry conditions and northerly surface winds may put much of the valley into Fire Marshal Conditions in the afternoon. A weak upper-level disturbance is forecast to flatten the ridge and turn the flow weakly onshore Friday. That will bring another cool-down to the region and a potential burning opportunity, especially for the north valley. A strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. Surface and transport winds are forcast to turn offshore Sunday and Monday. A weak westerly flow aloft is forecast to undercut the ridge and push into Northern California late Monday and Tuesday of next week. That may advance the thermal trough into Eastern Oregon and initiate a slow cooling trend across Western Oregon. The split-flow pattern in the jet stream that is forecast during the second half of next week would maintain dry condtions for Western Oregon with above normal temperatures. Weak onshore flow at times may create some limited burning opportunities, but no significant burning opportunity is forecast at this time. Tomorrow (11 Sep): Sunny and Warmer. 47/88 Fri (12 Sep): Mostly Sunny but Cooler with Increasing Onshore Flow. 49/81 Sat (13 Sep): Sunny and Warmer. North Winds. 49/84 Sun (14 Sep): Sunny and Very Warm. Northeast Winds. 53/90 Mon (15 Sep): Mostly Sunny and Continued Very Warm. Northeast Winds. 54/91 Tue (16 Sep): Mostly Sunny and Slightly Cooler. 52/86 Wed (17 Sep): Moslty Sunny and a Little Cooler. 50/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 11 08:26:09 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 11 Sep 2008 10:26:09 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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: Thursday, September 11th, 2008 at 9:00am. Burn Advisory: ...State Fire Marshal conditions will likely be reached this afternoon due to low humidities and increasing north-northeasterly winds... 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 of high pressure, that has been centered offshore for the past several days, will move over Oregon today. That will further strengthen the surface thermal trough, along the Oregon Coast. Valley temperatures should warm to near 90 degrees, under sunny skies, with continued offshore flow. The northern and central coastline will also have sunshine, warm temperatures, and offshore flow. Low-level winds had turned onshore along the south coast this morning, and that onshore flow will advance northward, along the coast, this afternoon and evening, as the surface themal trough shifts inland. The Salem sounding showed much warmer air aloft this morning, and a strong low-level temperature inversion, due to the building upper-level ridge of high pressure over the state. That will keep mixing heights at or below about 2000 feet until surface temperatures climb into the mid 80s this afternoon. By that time, low humidities] and increasing north-northeasterly surface winds will likely put much of the valley into State Fire Marshal Conditions. Open burning is highly unlikely today. The thermal trough is forecast to shift east of the Cascades overnight with a little marine air beginning to seep into the Willamette Valley by Friday morning. Low clouds will spread northward along the coastline overnight with little or no inland penetration by Friday morning. Surface Winds: NNE 5-12 this morning, NNE 10-17 G25 south this afternoon. Transport Winds: NNE 15 this morning, NE 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3400 feet. Ventilation index 51. High Temperature: Salem\'s high temperature today will be near 90. Humidities: Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 7:29pm; sunrise tomorrow: 6:48am. Extended Outlook: A weak upper-level disturbance is forecast to flatten the ridge, as it slide across Southern British Columbia Friday afternoon. That will push the surface thermal trough into Eastern Oregon and induce weak onshore flow into Western Oregon. Temperatures will cool slightly with the transport winds backing from northeasterly to northwesterly. That may create a burning opportunity Friday afternoon...especially in the north valley. This system is unlikely to be strong enough to create a burning opportunity for the south valley. A strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. Surface and transport winds are forcast to turn northerly Saturday, with highs in the low to mid 80s, and offshore by Sunday, as temperatures warm to near 90. The ridge is forecast to remain in place through at least Monday with low mixing heights and northerly transport winds severly limiting burning. A weak southwesterly flow aloft is forecast to advance the surface thermal trough into Eastern Oregon around Tuesday...initiating a slow cooling trend across Western Oregon. That may create open burning opportunities, or at least improve ventilation conditions enough for some prep burning, Tuesday through Thursday. Tomorrow (12 Sep): Mostly Sunny but Cooler with Increasing Onshore Flow. 52/84 Sat (13 Sep): Sunny and Warmer. North Winds. 49/84 Sun (14 Sep): Sunny and Very Warm. Northeast Winds. 55/92 Mon (15 Sep): Mostly Sunny and Continued Very Warm. 57/92 Tue (16 Sep): Sunny and Slightly Cooler. 55/86 Wed (17 Sep): Sunny and a Little Cooler. 51/83 Thu (18 Sep): Mostly Sunny with a Continued Cooling Trend. 50/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 11 09:11:52 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 11 Sep 2008 11:11:52 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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: Thursday, September 11th, 2008 at 9:00am. Burn Advisory: ...State Fire Marshal conditions will likely be reached this afternoon due to low humidities and increasing north-northeasterly winds... 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 of high pressure, that has been centered offshore for the past several days, will move over Oregon today. That will further strengthen the surface thermal trough, along the Oregon Coast. Valley temperatures should warm to near 90 degrees, under sunny skies, with continued offshore flow. The northern and central coastline will also have sunshine, warm temperatures, and offshore flow. Low-level winds had turned onshore along the south coast this morning, and that onshore flow will advance northward, along the coast, this afternoon and evening, as the surface themal trough shifts inland. The Salem sounding showed much warmer air aloft this morning, and a strong low-level temperature inversion, due to the building upper-level ridge of high pressure over the state. That will keep mixing heights at or below about 2000 feet until surface temperatures climb into the mid 80s this afternoon. By that time, low humidities] and increasing north-northeasterly surface winds will likely put much of the valley into State Fire Marshal Conditions. Open burning is highly unlikely today. The thermal trough is forecast to shift east of the Cascades overnight with a little marine air beginning to seep into the Willamette Valley by Friday morning. Low clouds will spread northward along the coastline overnight with little or no inland penetration by Friday morning. Surface Winds: NNE 5-12 this morning, NNE 10-17 G25 south this afternoon. Transport Winds: NNE 15 this morning, NE 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3400 feet. Ventilation index 51. High Temperature: Salem\'s high temperature today will be near 90. Humidities: Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 7:29pm; sunrise tomorrow: 6:48am. Extended Outlook: A weak upper-level disturbance is forecast to flatten the ridge, as it slide across Southern British Columbia Friday afternoon. That will push the surface thermal trough into Eastern Oregon and induce weak onshore flow into Western Oregon. Temperatures will cool slightly with the transport winds backing from northeasterly to northwesterly. That may create a burning opportunity Friday afternoon...especially in the north valley. This system is unlikely to be strong enough to create a burning opportunity for the south valley. A strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. Surface and transport winds are forcast to turn northerly Saturday, with highs in the low to mid 80s, and offshore by Sunday, as temperatures warm to near 90. The ridge is forecast to remain in place through at least Monday with low mixing heights and northerly transport winds severly limiting burning. A weak southwesterly flow aloft is forecast to advance the surface thermal trough into Eastern Oregon around Tuesday...initiating a slow cooling trend across Western Oregon. That may create open burning opportunities, or at least improve ventilation conditions enough for some prep burning, Tuesday through Thursday. Tomorrow (12 Sep): Mostly Sunny but Cooler with Increasing Onshore Flow. 52/84 Sat (13 Sep): Sunny and Warmer. North Winds. 49/84 Sun (14 Sep): Sunny and Very Warm. Northeast Winds. 55/92 Mon (15 Sep): Mostly Sunny and Continued Very Warm. 57/92 Tue (16 Sep): Sunny and Slightly Cooler. 55/86 Wed (17 Sep): Sunny and a Little Cooler. 51/83 Thu (18 Sep): Mostly Sunny with a Continued Cooling Trend. 50/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 11 09:16:22 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 11 Sep 2008 11:16:22 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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: Thursday, September 11th, 2008 at 9:00am. Burn Advisory: ...State Fire Marshal conditions will likely be reached this afternoon due to low humidities and increasing north-northeasterly winds... 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 of high pressure, that has been centered offshore for the past several days, will move over Oregon today. That will further strengthen the surface thermal trough, along the Oregon Coast. Valley temperatures should warm to near 90 degrees, under sunny skies, with continued offshore flow. The northern and central coastline will also have sunshine, warm temperatures, and offshore flow. Low-level winds had turned onshore along the south coast this morning, and that onshore flow will advance northward, along the coast, this afternoon and evening, as the surface themal trough shifts inland. The Salem sounding showed much warmer air aloft this morning, and a strong low-level temperature inversion, due to the building upper-level ridge of high pressure over the state. That will keep mixing heights at or below about 2000 feet until surface temperatures climb into the mid 80s this afternoon. By that time, low humidities] and increasing north-northeasterly surface winds will likely put much of the valley into State Fire Marshal Conditions. Open burning is highly unlikely today. The thermal trough is forecast to shift east of the Cascades overnight with a little marine air beginning to seep into the Willamette Valley by Friday morning. Low clouds will spread northward along the coastline overnight with little or no inland penetration by Friday morning. Surface Winds: NNE 5-12 this morning, NNE 10-17 G25 south this afternoon. Transport Winds: NNE 15 this morning, NE 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3400 feet. Ventilation index 51. High Temperature: Salem\'s high temperature today will be near 90. Humidities: Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 7:29pm; sunrise tomorrow: 6:48am. Extended Outlook: A weak upper-level disturbance is forecast to flatten the ridge, as it slide across Southern British Columbia Friday afternoon. That will push the surface thermal trough into Eastern Oregon and induce weak onshore flow into Western Oregon. Temperatures will cool slightly with the transport winds backing from northeasterly to northwesterly. That may create a burning opportunity Friday afternoon...especially in the north valley. This system is unlikely to be strong enough to create a burning opportunity for the south valley. A strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. Surface and transport winds are forcast to turn northerly Saturday, with highs in the low to mid 80s, and offshore by Sunday, as temperatures warm to near 90. The ridge is forecast to remain in place through at least Monday with low mixing heights and northerly transport winds severly limiting burning. A weak southwesterly flow aloft is forecast to advance the surface thermal trough into Eastern Oregon around Tuesday...initiating a slow cooling trend across Western Oregon. That may create open burning opportunities, or at least improve ventilation conditions enough for some prep burning, Tuesday through Thursday. Tomorrow (12 Sep): Mostly Sunny but Cooler with Increasing Onshore Flow. 52/84 Sat (13 Sep): Sunny and Warmer. North Winds. 49/84 Sun (14 Sep): Sunny and Very Warm. Northeast Winds. 55/92 Mon (15 Sep): Mostly Sunny and Continued Very Warm. 57/92 Tue (16 Sep): Sunny and Slightly Cooler. 55/86 Wed (17 Sep): Sunny and a Little Cooler. 51/83 Thu (18 Sep): Mostly Sunny with a Continued Cooling Trend. 50/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 11 09:29:25 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 11 Sep 2008 11:29:25 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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: Thursday, September 11th, 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, centered offshore for the past several days, will move over Oregon today. That will further strengthen the surface thermal trough, along the Oregon Coast. Valley temperatures should warm to near 90 degrees, under sunny skies, with continued offshore flow. The northern and central coastline will also have sunshine, warm temperatures, and offshore flow. Low-level winds had turned onshore along the south coast this morning. Onshore flow will advance northward, along the coast, this afternoon and evening, as the surface thermal trough shifts inland. The Salem sounding showed much warmer air aloft this morning, and a strong low-level temperature inversion, due to the building upper-level ridge of high pressure. That will keep mixing heights at or below about 2000 feet until surface temperatures climb into the mid 80s this afternoon. By that time, low humidties and increasing north-northeasterly surface winds will likely put much of the valley into State Fire Marshal Conditions. Open burning is highly unlikely today. The thermal trough is forecast to shift east of the Cascades overnight with a little marine air beginning to seep into the Willamette Valley by Friday morning. Low clouds will spread northward along the coastline overnight with little or no inland penetration by Friday morning. Surface Winds: NNE 5-12 this morning, NNE 10-17 G25 south this afternoon. Transport Winds: NNE 15 this morning, NE 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3400 feet. Ventilation index 51. High Temperature: Salem\'s high temperature today will be near 90. Humidities: Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 7:29pm; sunrise tomorrow: 6:48am. Extended Outlook: A weak upper-level disturbance is forecast to flatten the ridge, as it slides across Southern British Columbia Friday afternoon. That will push the surface thermal trough into Eastern Oregon and induce weak onshore flow into Western Oregon. Temperatures will cool slightly with the transport winds backing from northeasterly to northwesterly. That may create a burning opportunity Friday afternoon...especially in the north valley. This system is unlikely to be strong enough to create a burning opportunity for the south valley. A strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. Surface and transport winds are forecast to turn northerly Saturday. By Sunday, the transport winds will turn offshore, with temperatures warming into the low 90s. The ridge is forecast to remain in place through at least Monday with low mixing heights and northerly transport winds severly limiting burning opportunities. A weak southwesterly flow aloft is forecast to advance the surface thermal trough into Eastern Oregon around Tuesday...initiating a slow cooling trend across Western Oregon. That may create open burning opportunities, or at least improve ventilation conditions enough for some prep burning, Tuesday through Thursday. Tomorrow (12 Sep): Mostly Sunny but Cooler with Increasing Onshore Flow. 52/84 Sat (13 Sep): Sunny and Warmer. North Winds. 49/84 Sun (14 Sep): Sunny and Very Warm. Northeast Winds. 55/92 Mon (15 Sep): Mostly Sunny and Continued Very Warm. 57/92 Tue (16 Sep): Sunny and Slightly Cooler. 55/86 Wed (17 Sep): Sunny and a Little Cooler. 51/83 Thu (18 Sep): Mostly Sunny with a Continued Cooling Trend. 50/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 11 09:41:30 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 11 Sep 2008 11:41:30 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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: Thursday, September 11th, 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, centered offshore for the past several days, will move over Oregon today. That will further strengthen the surface thermal trough, along the Oregon Coast. Valley temperatures should warm to near 90 degrees, under sunny skies, with continued offshore flow. The northern and central coastline will also have sunshine, warm temperatures, and offshore flow. Low-level winds had turned onshore along the south coast this morning. Onshore flow will advance northward, along the coast, this afternoon and evening, as the surface thermal trough shifts inland. The Salem sounding showed much warmer air aloft this morning, and a strong low-level temperature inversion, due to the building upper-level ridge of high pressure. That will keep mixing heights at or below about 2000 feet until surface temperatures climb into the mid 80s this afternoon. By that time, low humidties and increasing north-northeasterly surface winds will likely put much of the valley into State Fire Marshal Conditions. Open burning is highly unlikely today. The thermal trough is forecast to shift east of the Cascades overnight with a little marine air beginning to seep into the Willamette Valley by Friday morning. Low clouds will spread northward along the coastline overnight with little or no inland penetration by Friday morning. Surface Winds: NNE 5-12 this morning, NNE 10-17 G25 south this afternoon. Transport Winds: NNE 15 this morning, NE 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3400 feet. Ventilation index 51. High Temperature: Salem\'s high temperature today will be near 90. Humidities: Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 7:29pm; sunrise tomorrow: 6:48am. Extended Outlook: A weak upper-level disturbance is forecast to flatten the ridge, as it slides across Southern British Columbia Friday afternoon. That will push the surface thermal trough into Eastern Oregon and induce weak onshore flow into Western Oregon. Temperatures will cool slightly with the transport winds backing from northeasterly to northwesterly. That may create a burning opportunity Friday afternoon...especially in the north valley. This system is unlikely to be strong enough to create a burning opportunity for the south valley. A strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. Surface and transport winds are forecast to turn northerly Saturday. By Sunday, the transport winds will turn offshore, with temperatures warming into the low 90s. The ridge is forecast to remain in place through at least Monday with low mixing heights and northerly transport winds severly limiting burning opportunities. A weak southwesterly flow aloft is forecast to advance the surface thermal trough into Eastern Oregon around Tuesday...initiating a slow cooling trend across Western Oregon. That may create open burning opportunities, or at least improve ventilation conditions enough for some prep burning, Tuesday through Thursday. Tomorrow (12 Sep): Mostly Sunny but Cooler with Increasing Onshore Flow. 52/84 Sat (13 Sep): Sunny and Warmer. North Winds. 49/84 Sun (14 Sep): Sunny and Very Warm. Northeast Winds. 55/92 Mon (15 Sep): Mostly Sunny and Continued Very Warm. 57/92 Tue (16 Sep): Sunny and Slightly Cooler. 55/86 Wed (17 Sep): Sunny and a Little Cooler. 51/83 Thu (18 Sep): Mostly Sunny with a Continued Cooling Trend. 50/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 11 11:14:05 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 11 Sep 2008 13:14:05 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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: Thursday, September 11th, 2008 at 12:00pm. Burn Advisory: ...State Fire Marshal conditions are likely this afternoon, due to low humidities and increasing north-northeasterly winds... 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, centered offshore for the past several days, is moving over Oregon today. The late-morning ODA surface analysis showed a broad surface thermal trough along the Oregon Coast. North-northeasterly gradients were producing sunny skies and offshore winds across most of Western Oregon. The lone exception was along the south coast, where onshore flow was producing foggy and cool conditions. Valley temperatures, along with the northern and central coast, had climbed into the low to mid 70s by late this morning with sunny skies. Relative humidities, in the valley, were already near 30%, so State Fire Marshal conditions will likely be met this afternoon, where surface winds are 15 mph or greater. Meanwhile, on the south coast, Brookings was a foggy 50 degrees. Onshore flow will advance northward, along the coast, this evening, as the surface thermal trough slowly shifts inland. It is forecast to shift east of the Cascades overnight with a little marine air beginning to seep into the Willamette Valley by Friday morning. Low clouds will spread northward along the coastline overnight with little or no inland penetration by Friday morning. Surface Winds: NNE 7-17 G20 this afternoon. Transport Winds: NE 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3400 feet. Ventilation index 51. High Temperature: Salem\'s high temperature today will be near 90. Humidities: Minimum relative humidity will be near 23%. Sunrise/Sunset: Salem sunset tonight: 7:29pm; sunrise tomorrow: 6:48am. Extended Outlook: A weak upper-level disturbance is forecast to flatten the ridge, as it slides across Southern British Columbia Friday afternoon. That will push the surface thermal trough into Eastern Oregon and induce weak onshore flow into Western Oregon. Temperatures will cool slightly with the transport winds backing from northeasterly to northwesterly. That may create a brief burning opportunity, Friday afternoon, for extreme north valley fields, but transport winds are forecast to stay northerly south of Salem. A strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. Surface and transport winds are forecast to turn northerly Saturday. By Sunday, the transport winds will turn offshore, with temperatures warming into the low 90s. The ridge is forecast to remain in place through at least Monday with low mixing heights and northerly transport winds severly limiting burning opportunities. A weak South-southwesterly flow aloft is forecast, beginning Tuesday, with a slight chance of mainly mountain thunderstorms, from a weak upper-level low pressure system off the Northern California Coast. The surface thermal trough will shift into Eastern Oregon...initiating a slow cooling trend across Western Oregon. That may create open burning opportunities, or at least improve ventilation conditions enough for some prep burning, Tuesday afternoon through Thursday. Tomorrow (12 Sep): Mostly Sunny but Cooler with Increasing Onshore Flow. 52/84 Sat (13 Sep): Sunny and Warmer. North Winds. 49/84 Sun (14 Sep): Sunny and Very Warm. Northeast Winds. 55/92 Mon (15 Sep): Mostly Sunny and Continued Very Warm. 57/92 Tue (16 Sep): Mostly Sunny. Slightly Cooler. 55/86 Wed (17 Sep): Partly Cloudy. 51/83 Thu (18 Sep): Partly Cloudy. 50/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Sep 12 08:04:36 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 12 Sep 2008 10:04:36 -0500 Subject: [willamette-fcst] Forecast - Friday, September 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: Friday, September 12th, 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 ridge of high pressure remained over Oregon this morning with weak northwesterly flow aloft. The ODA surface analysis showed the thermal trough had shifted east of the coastal range into the western valleys overnight. Pressure gradients were weak over the valley this morning with light winds. Even with a warm air mass over the region, clear skies and longer nights allowed valley temperatures to locally drop into the upper 40s this morning. The Salem sounding this morning continued to show very warm air aloft, so mixing heights will stay below 3000 feet until mid to late afternoon. There was some cooling above 10,000 feet, where winds had backed from northeasterly to northwesterly (onshore). That shift to an onshore wind direction will drop closer to the surface as the day progresses. By late this afternoon, the air aloft should cool enough to lift mixing heights to about 4000 feet. The air mass is still very dry this morning, with dew-point temperatures in the mid to upper 40s. If the weak onshore flow does not moisten the low-level air mass, relative humidities may drop to near or below 30 percent this afternoon. North-northwesterly winds may locally reach 15 mph, so State Fire Marshal conditions are not out of the question, again, this afternoon...especially in the south valley. A weak upper-level disturbance is forecast to flatten the ridge, as it slides across Southern British Columbia this afternoon. That will push the surface thermal trough into Eastern Oregon and induce weak onshore flow west of the Cascades. That should cap high temperatures in the mid 80s, after reaching 90 degrees Thursday. Although unlikely, transport winds may back enough northwesterly to allow for open burning late this afternoon in the north valley. Transport winds are forecast to stay northerly south of about Salem. The upper-level ridge is forecast to rapidly build back over the region with surface winds becoming northerly overnight. Little to no marine clouds are forecast to penetrate east of the coast range with this weak influx of marine air. Surface Winds: N 5-10 this morning, NNW 7-14 north valley; N 8-16 south valley this afternoon. Transport Winds: NNE 8 this morning, N 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 40. High Temperature: Salem\'s high temperature today will be near 84. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 30%. Sunrise/Sunset: Salem sunset tonight: 7:28pm; sunrise tomorrow: 6:49am. Extended Outlook: A strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. Northerly surface and transport winds are forecast Saturday. By Sunday, a strong thermal tough along the coast should turn transport winds offshore, with valley temperatures warming into the low 90s. Little change in the weather pattern is expected Monday, with continued warming aloft leading to very low mixing. A light southwesterly flow aloft is forecast, beginning Tuesday. A weak upper-level trough, off the northern California Coast, may send enough moisture northward over southern Oregon for a slight chance of mainly mountain thunderstorms. Otherwise, dry conditions are forecast to continue with a slow cooling trend, as the surface thermal trough shifts into Eastern Oregon and eventually into Idaho. Increasing onshore flow may create some limited open burning opportunities during the second half of next week or at least improve ventilation conditions enough for some prep burning. Tomorrow (13 Sep): Sunny and Warm. North Winds. 48/84 Sun (14 Sep): Sunny and Very Warm. Northeast Winds. 49/92 Mon (15 Sep): Mostly Sunny and Continued Very Warm. 53/93 Tue (16 Sep): Mostly Sunny and Warm. 53/88 Wed (17 Sep): Mostly Sunny. A Little Cooler. 53/84 Thu (18 Sep): Mostly Sunny. 50/82 Fri (19 Sep): Mostly Sunny. 50/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Sep 12 11:18:13 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 12 Sep 2008 13:18:13 -0500 Subject: [willamette-fcst] Forecast - Friday, September 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: Friday, September 12th, 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 remains over Oregon with weak northwesterly flow aloft. Satellite imagery showed mostly clear skies over Oregon late this morning with the exception of low clouds blanketing the immediate coastline. The late-morning ODA surface analysis showed the thermal trough over the Willamette valley was beginning to shift eastward. Winds in the valley were still light northerly. Temperatures had already warmed into the low to mid 70s. The Salem sounding this morning continued to show very warm air aloft, so mixing heights will stay below 3000 feet until mid afternoon. There was some cooling above 10,000 feet, where winds had backed from northeasterly to northwesterly (onshore). That shift to an onshore wind direction will drop closer to the surface as the day progresses. An 11:40am pibal reading over Salem showed mostly northerly winds below 5000 feet with a shift to northwesterly above 5000 feet. The northwesterly winds aloft should drop closer to the surface by late this afternoon with cooling aloft lifting mixing heights above 4000 feet. The air mass is still very dry, but dew-point temperatures are beginning to rise in the north valley and may come up enough to avoid Fire marshal conditions this afternoon. The south valley will be drier, and increasing northerly winds this afternoon could put areas of the south valley into Fire Marshal conditions. Satellite imagery showed a band of high clouds stretching from NE Washington to North-Central Oregon. Those clouds are associated with a weak upper-level disturbance that is sliding across Southern British Columbia. It is responsible for the eastward shift of the surface thermal trough late this morning. The thermal trough will push into Eastern Oregon by late this afternoon and induce weak onshore flow west of the Cascades. That should cap high temperatures in the mid 80s. Transport winds may back enough northwesterly to allow for open burning late this afternoon in the north valley. Transport winds are forecast to stay northerly south of about Salem. We will begin pibal readings in the north and south valley at 2 pm. The upper-level ridge is forecast to rapidly build back over the region with surface winds becoming northerly overnight. Little to no marine clouds are forecast to penetrate east of the coast range with this weak influx of marine air. Surface Winds: N 5-10...becoming NNW 7-14 north valley; N 8-16 south valley this afternoon. Transport Winds: N 10-15...becoming NNW 10-15 north valley 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 84. Humidities: Minimum relative humidity will be near 30% (likely a little above north and below south). Sunrise/Sunset: Salem sunset tonight: 7:28pm; sunrise tomorrow: 6:49am. Extended Outlook: A strong upper-level ridge is forecast to build over the Pacific Northwest this weekend for sunny and warmer weather. Northerly surface and transport winds are forecast Saturday. By Sunday, a strong thermal tough along the coast should turn transport winds offshore, with valley temperatures warming into the low 90s. Little change in the weather pattern is expected Monday with poor ventialtion conditions expected. A light southwesterly flow aloft is forecast, beginning Tuesday. A weak upper-level trough, off the northern California Coast, may send enough moisture northward over southern and eastern Oregon for a slight chance of mainly mountain thunderstorms. Otherwise, dry conditions are forecast to continue with a slow cooling trend, as the surface thermal trough shifts into Eastern Oregon and eventually into Idaho. Increasing onshore flow may create some limited open burning opportunities during the second half of next week or at least improve ventilation conditions enough for some prep burning. Tomorrow (13 Sep): Sunny and Warm. North Winds. 48/84 Sun (14 Sep): Sunny and Very Warm. Northeast Winds. 49/92 Mon (15 Sep): Mostly Sunny and Continued Very Warm. 53/93 Tue (16 Sep): Mostly Sunny and Warm. 53/88 Wed (17 Sep): Mostly Sunny. A Little Cooler. 53/84 Thu (18 Sep): Mostly Sunny. 50/82 Fri (19 Sep): Mostly Sunny. 50/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Sep 15 08:04:11 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 15 Sep 2008 10:04:11 -0500 Subject: [willamette-fcst] Forecast - Monday, September 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: Monday, September 15th, 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 broad upper-level ridge of high pressure built over the Pacific Northwest during the weekend with the low-level flow turning offshore by Sunday and helping warm valley temperatures to near 90 degrees. The ridge axis extended from Ariznon through Nevada and Eastern Oregon, northwestward to SE Alaska this morning. It was so broad that it was producing generally clear skies over the western third of the U.S. and most of British Columbia. The ODA surface analysis showed a thermal trough extending from the Southern Oregon to the Northern Washington Coast with offshore flow continuing to bring clear skies to most of Western Oregon. The exception was along the Central and Southern Oregon Coast, where onshore flow was slowly advancing a blanket of low clouds and fog northward. It had advance about to Newport by mid-morning. The sounding over Salem this morning showed further warming aloft since Sunday, so valley temperatures will top out several degrees warmer today. Highs should climb into the mid 90s this afternoon, which will threaten some daily records. The very warm air aloft will keep mixing heights below 3000 feet today with north-northeasterly transport winds. In additions, State Fire Marshal conditions may be reached late this afternoon due to the hot temperatures and low relative humidities. Surface Winds: N 3-8 this morning, N 5-12 this afternoon. Transport Winds: NE 6 this morning, NNE 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2800 feet. Ventilation index 22. High Temperature: Salem\'s high temperature today will be near 95. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 20%. Sunrise/Sunset: Salem sunset tonight: 7:22pm; sunrise tomorrow: 6:53am. Extended Outlook: The upper-level ridge is forecast to slowly shift eastward Tuesday with light south-southwesterly flow aloft developing. The broad thermal trough is forecast to move over the Willamette Valley for another very warm afternoon. Some marine air may seep into the valley late in the afternoon...capping high temperatures a couple of degrees cooler than on Monday, but daily records will, once again, be threatened. Mixing heights will remain very low due to warm air aloft. A weak upper-level low pressure system is forecast to move onto the Northern California Coast Wednesday, with increasing south-southwesterly flow aloft over Oregon. Increasing mid and high level moisture will combine with daytime heating to trigger scattered shower and thundershower activity...mainly over the Cascades. The surface thermal trough is forecast to shift eastward to over Eastern Oregon and Idaho. That will bring cooler onshore flow into Western Oregon. There may be a burning opportunity with the transition to cooler conditions Wednesday. However, southerly flow aloft and the possible development of thunderstorms over the Cascades makes that questionable. A stronger upper-level low pressure system is forecast to take a similar track and approach the Northern California Coastline by Thursday afternoon. South-southwesterly flow aloft will increase over Oregon with a chance of showers moving into Western Oregon late in the day. This system also has the potential to produce a burning opportunity with increasing onshore flow possibly turning transport winds westerly. Once again, limiting factors could be the presence of showers and too much southerly flow aloft. The computer models have considerable disagreement, beginning late this week, so my confidence in the extended forecast details is below average. The second upper-level low pressure system appears as if it will slide across Northern California Thursday, with a split-fow jet stream pattern Friday and Saturday for Oregon. That would bring dry conditions to Western Oregon with weak onshore flow. The next weather system is forecast to approach the coastal waters late Sunday and Monday, with the flow aloft becoming more southwesterly over Oregon. Depending on the timing and strength of that system, it may present a burning opportunity either Sunday or Monday. Tomorrow (16 Sep): Sunny. 53/93 Wed (17 Sep): Increasing Clouds. Slight Chance of T-Storms. 53/81 Thu (18 Sep): Mostly Cloudy. Chance of Showers Late. 53/75 Fri (19 Sep): Partly Cloudy. 50/76 Sat (20 Sep): Partly Cloudy. 50/77 Sun (21 Sep): Partly Cloudy. 49/76 Mon (22 Sep): Increasing Clouds. Chance of Showers Late. 48/75 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Sep 15 08:31:50 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 15 Sep 2008 10:31:50 -0500 Subject: [willamette-fcst] Forecast - Monday, September 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: Monday, September 15th, 2008 at 9:25am. ...Corrected temperatures on extended forecast... 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 broad upper-level ridge of high pressure built over the Pacific Northwest during the weekend with the low-level flow turning offshore by Sunday and helping warm valley temperatures to near 90 degrees. The ridge axis extended from Arizona through Nevada, and Eastern Oregon, northwestward to SE Alaska this morning. It was producing generally clear skies over the western third of the U.S. and most of British Columbia. The ODA surface analysis showed a thermal trough extending from the Southern Oregon to the Northern Washington Coast with offshore flow continuing to bring clear skies to most of Western Oregon. The exception was along the Central and Southern Oregon Coast, where onshore flow was slowly advancing a blanket of low clouds and fog northward. It had advanced about to Newport by mid-morning. The sounding over Salem this morning showed further warming aloft since Sunday, so valley temperatures will top out several degrees warmer today. Highs should climb into the mid 90s this afternoon, which will threaten some daily records. The very warm air aloft will keep mixing heights below 3000 feet today with north-northeasterly transport winds. In additions, State Fire Marshal conditions may be reached late this afternoon due to the hot temperatures and low relative humidities. Surface Winds: N 3-8 this morning, N 5-12 this afternoon. Transport Winds: NE 6 this morning, NNE 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2800 feet. Ventilation index 22. High Temperature: Salem\'s high temperature today will be near 95. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 20%. Sunrise/Sunset: Salem sunset tonight: 7:22pm; sunrise tomorrow: 6:53am. Extended Outlook: The upper-level ridge is forecast to slowly shift eastward Tuesday with light south- southwesterly flow aloft developing. The broad thermal trough is forecast to move over the Willamette Valley for another very warm afternoon. Some marine air may seep into the valley late in the afternoon...capping high temperatures a couple of degrees cooler than today, but daily records will, once again, be threatened. Mixing heights will remain very low due to warm air aloft. A weak upper-level low pressure system is forecast to move onto the Northern California Coast Wednesday, with increasing south-southwesterly flow aloft over Oregon. Increasing mid and high level moisture will combine with daytime heating to trigger scattered shower and thundershower activity...mainly over the Cascades. The surface thermal trough is forecast to shift eastward to over Eastern Oregon and Idaho. That will bring cooler onshore flow into Western Oregon. There may be a burning opportunity with the transition to cooler conditions Wednesday. However, southerly flow aloft and the possible development of thunderstorms over the Cascades makes that questionable. A stronger upper-level low pressure system is forecast to take a similar track and approach the Northern California Coastline by Thursday afternoon. South-southwesterly flow aloft will increase over Oregon with a chance of showers moving into Western Oregon late in the day. This system also has the potential to produce a burning opportunity with increasing onshore flow more westerly transport winds. Once again, limiting factors could be the presence of showers/t-storms and too much southerly flow aloft. The computer models have considerable disagreement, beginning late this week, so my confidence in the extended forecast details is below average. The second upper-level low pressure system appears as if it will slide across Northern California Thursday, with a split-fow jet stream pattern Friday and Saturday for Oregon. That would bring dry conditions to Western Oregon with weak onshore flow. The next weather system is forecast to approach the coastal waters late Sunday and Monday, with the flow aloft becoming more southwesterly over Oregon. Depending on the timing and strength of that system, it may present a burning opportunity either Sunday or Monday. Tomorrow (16 Sep): Sunny. 53/93 Wed (17 Sep): Increasing Clouds. Slight Chance of T-Storms. 53/81 Thu (18 Sep): Mostly Cloudy. Chance of Showers Late. 53/75 Fri (19 Sep): Partly Cloudy. 50/76 Sat (20 Sep): Partly Cloudy. 50/77 Sun (21 Sep): Partly Cloudy. 50/80 Mon (22 Sep): Increasing Clouds. Chance of Showers Late. 50/75 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Sep 16 08:04:48 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 16 Sep 2008 10:04:48 -0500 Subject: [willamette-fcst] Forecast - Tuesday, September 16th, 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, September 16th, 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 massive upper-level ridge of high pressure that has been responsible for this late-summer heat wave will bring one more day of near-record warmth to the interior of Western Oregon. The ridge is beginning to expand eastward and encompasses most of the western half of the country. The axis of the ridge extended from Colorado northwestward, through Northern Idaho, to SE Alaska. Increasing southerly flow aloft is transporting smoke, mostly from California wildfires, northward over Oregon...making for hazy conditions. That will continue today, as the upper-level ridge slowly shifts to the east. The ODA surface analysis showed a thermal trough stretching across the interior of Western Oregon with onshore flow onto the immediate coastline and offshore flow from the Willamette Valley to the Idaho border. Satellite imagery showed low clouds and fog along the coast and generally clear skies over the rest of Oregon. Some high clouds were circulating around a weak upper-level disturbance, off the Northern California Coast, northward over Oregon. It may circulate enough moisture into Southern Oregon for afternoon heating to set of a few mountain thunderstorms this afternoon. Sunshine over the Willamette Valley will lift temperatures to near 90 again this afternoon. Some filtering of the sun by the upper-level smoke will likely keep temperature below record levels. The coastline will see temperatures in the realtively chilly upper 50s and 60s with low clouds and fog. The Salem sounding this morning showed even more warming aloft, so mixing heights will stay below 2000 feet for most, if not all, of the day. However, the thermal trough may shift into Central Oregon late this afternoon, which would induce weak onshore flow into the Willamette Valley. If that combines with a little cooling aloft, it could create a brief burning opportunity late this afternoon, but the latest computer guidance suggests that is unlikely. The California disturbance is forcast to move into Southern Oregon overnight with a chance of, mainly mountain, showers of thunderstorms moving northward across Oregon. Weak onshore flow will likely bring some marine air into the Willamette Valley for the beginning of a cooling trend. There may even be some low clouds to start the day Wednesday. Surface Winds: Var 0-5 this morning, N 4-8...becoming SW 5-10 late this afternoon. Transport Winds: NE 5 this morning, NW 5 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2500 feet. Ventilation index 13. High Temperature: Salem\'s high temperature today will be near 91. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 7:20pm; sunrise tomorrow: 6:54am. Extended Outlook: A weak upper-level trough will move northward, from Northern California, across Oregon Wednesday. It will cool the air aloft and bring a chance of showers and thundershowers mainly to areas from the Cascades eastward. The surface thermal trough is forecast to shift eastward, to over Eastern Oregon and Idaho, wit increasing onshore flow cooling temperatures west of the Cascades closer to normal. This transition may create a burning opportunity Wednesday afternoon. However, southerly flow aloft and the possible development of showers and thunderstorms over the Cascades makes that questionable. A stronger upper-level low pressure system is forecast to approach the Northern California Coastline by Thursday afternoon but stay south of Oregon, when it comes onshore Friday. South-southwesterly flow aloft will increase over Oregon, but not much in the way of shower activity is forecast this far north. This system also has the potential to produce a burning opportunities Thursday and Friday. However, the transport winds may be too weak with southerly flow aloft. The computer models have considerable disagreement, beginning late this week, so my confidence in the extended forecast details is below average. A split-flow jet stream pattern is forecast by Saturday, with one branch to our south and the other to our north, leaving Oregon in a dry weather pattern with weak onshore flow making for seasonal temperatures. That could create burning opportunities over the weekend. The next weather system is forecast to approach the coastline Monday, but it also looks to be fairly dry Tomorrow (17 Sep): Partly Cloudy. 52/83 Thu (18 Sep): Partly Cloudy. 52/78 Fri (19 Sep): Partly Cloudy. 52/76 Sat (20 Sep): Partly Cloudy. 51/76 Sun (21 Sep): Partly Cloudy. 49/76 Mon (22 Sep): Partly Cloudy. 48/73 Tue (23 Sep): Partly Cloudy. 47/73 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Sep 16 11:32:25 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 16 Sep 2008 13:32:25 -0500 Subject: [willamette-fcst] Forecast - Tuesday, September 16th, 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, September 16th, 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 massive upper-level ridge of high pressure that has been responsible for this late-summer heat wave will bring one more day of near-record warmth to the interior of Western Oregon. The ridge is beginning to expand eastward and was centered over Colorado late this morning. The ridge encompasses most of the western half of the country with the axis extending northwestward, through Northern Idaho, to SE Alaska. Increasing southerly flow aloft is coninuing to transport California wildfire smoke northward over Oregon...making for hazy conditions. The late-morning ODA surface analysis showed a thermal trough extending from SW Oregon, through the Willamette Valley, to just off the Washington Coast. Offshore flow was continuing over all of Oregon...east of the coast range. Satellite imagery showed low clouds and fog along the coast and generally clear skies over the rest of Oregon. Some high clouds were circulating around a weak upper-level disturbance, off the Northern California Coast, northward over mainly SW Oregon. Enough moisture may circulate into Southern Oregon for afternoon heating to generate a few mountain thunderstorms later this afternoon. Willamette valley temperatures had already warmed into the low to mid 70s by midday. Hazy Sunshine will further lift inland temperatures to near 90 this afternoon. The warmth of the air aloft supports even warmer surface temperatures, but wildfire smoke is blocking some sunlight. The coastline was still in the 50s late this morning and will struggle to reach 60 degrees with onshore flow maintaining low clouds and fog. The Salem sounding this morning showed even more warming aloft, since Monday, so mixing heights were estimated to be only about 1000 feet late this morning and will stay below 2000 feet for most, if not all, of the day. There are some changes taking place that could improve ventilation conditions later this afternoon. The upper-level ridge is slowly shifting east, so the the surface thermal trough may also shift into Central Oregon late this afternoon. That would induce weak onshore flow and potentially turn transport winds more westerly. The air aloft will still be very warm, so mixing heights will not likely exceed about 2500 feet. We will monitor the transport winds, via pibals, starting at 2pm, but the outlook for open burning today remains doubtful. The California disturbance is forcast to move into Southern Oregon overnight with a chance of, mainly mountain, showers or thunderstorms. Weak onshore flow will likely bring some cooler air into the Willamette Valley overnight but little or no marine clouds. Surface Winds: Var 0-5...possibly becoming SW 5-10 late this afternoon. Transport Winds: Light...Becoming SW 5 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2500 feet. Ventilation index 13. High Temperature: Salem\'s high temperature today will be near 91. Humidities: Minimum relative humidity will be near 26%. Sunrise/Sunset: Salem sunset tonight: 7:20pm; sunrise tomorrow: 6:54am. Extended Outlook: A weak upper-level trough will move northward, across Oregon, Wednesday. It will cool the air aloft and bring a slight chance of showers and thundershowers...mainly from the Cascades eastward. The surface thermal trough is forecast to shift into Eastern Oregon and Idaho, with increasing onshore flow cooling temperatures west of the Cascades closer to normal. This transition has the highest potential of creating an open burning opportunity, Wednesday afternoon, that most of the valley has seen for a couple of weeks. However, there are some potential limiting factors. Southerly flow aloft may keep mixing heights fairly low (near 3000 feet), and potenital thundershower development may create poor gradient-stacking and not allow for good evacuation of smoke over the Cascades. Another upper-level low pressure system is forecast to approach the Northern California Coastline Thursday afternoon with increasing south-southwesterly flow aloft and continued onshore flow at the surface. This system should bring a little more cooling to Western Oregon but not much inthe way of precipitation, as it comes onshore late Thursday and Friday. This system also has the potential to produce burning opportunities. A split-flow jet stream pattern is forecast by Saturday, with one branch to our south and the other to our north, leaving Oregon in a dry weather pattern with weak onshore flow making for seasonal temperatures. That could create burning opportunities over the weekend. The next weather system is forecast to approach the Sunday or Monday and may bring some light rain to the region. Tomorrow (17 Sep): Partly Cloudy. 52/83 Thu (18 Sep): Mostly Sunny. 50/78 Fri (19 Sep): Increasing Clouds. 52/78 Sat (20 Sep): Partly Cloudy. 51/76 Sun (21 Sep): Increasing Clouds. Chance of Light Rain Late. 50/74 Mon (22 Sep): Chance of Showers and Cooler. 48/68 Tue (23 Sep): Partly Cloudy. 45/68 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Sep 17 11:04:37 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 17 Sep 2008 13:04:37 -0500 Subject: [willamette-fcst] Forecast - Wednesday, September 17th, 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, September 17th, 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 strong ridge of high pressure that has been giving Oregon a late-summer hot spell is moving to the east and will allow a weak upper-level trough to move northward, across Eastern Oregon, today. That will destabilize the atmosphere and lead to thunderstorm development today...mainly east of the Cascades. South-southeasterly flow aloft is continuing to circulate California wildfire smoke over Oregon, so we will see a mix of clouds and hazy sunshine over the state today. The late-morning ODA surface analysis showed a broad surface thermal trough extending from SW Oregon northward through the Eastern Willamette Valley to near The Dalles. It is slowly shifting eastward and is forecast to move into Central Oregon this afternoon. Midday valley temperatures were near 70 degrees with hazy sunshine. Increasing onshore flow should cap Willamette Valley temperatures in the low 80s this afternoon. Satelliete imagery showed low clouds along the entire Washington and Oregon Coastlines. The low clouds had not penetrated inland, beyond the coastal range, due to the presence of the thermal trough in the Willamette Valley. Lots of clouds were circulating northward across the eastern half of the state and may develop into scattered showers and thunderstorms this afternoon. The air aloft has cooled some since Tuesday morning, but mixing heights are forecast to remain below 3000 feet until mid-afternoon. As the upper-level trough sweeps northward, across Eastern Oregon this afternoon, transport winds should veer from southeasterly to south-southwesterly. Mixing heights may climb to near 4000 feet later this afternoon, but some minor waring aloft may hold mixing heights near or just below 3000 feet. There may be an open burning opportunity during the mid-to-late afternoon period, after the thermal trough shifts out of the Willamette Valley and into Central Oregon. However, transport winds may be too southerly to allow for burning with mixing heights perhaps no higher than 3000 feet. Thundershowers appear as if they will stay mainly in Eastern Oregon, so they should be less of a factor than previously forecast. Surface Winds: Becoming SW 5-12 this afternoon. Transport Winds: S to SW 9 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be 3-4000 feet. Ventilation index 36. High Temperature: Salem\'s high temperature today will be near 83. Humidities: Minimum relative humidity will be near 35%. Sunrise/Sunset: Salem sunset tonight: 7:18pm; sunrise tomorrow: 6:55am. Extended Outlook: Another upper-level low pressure system is forecast to approach the Northern California Coastline Thursday afternoon with increasing south-southwesterly flow aloft and continued onshore flow at the surface. This system should bring a little more cooling to Western Oregon with a slight chance of showers, as it comes onshore late Thursday and Friday. This system will likely bring showers to Southern and Eastern Oregon. It may also create more favorable conditions for burning. A split-flow jet stream pattern is forecast by Saturday, with one branch to our south and the other to our north, leaving Oregon in a dry weather pattern with weak onshore flow making for seasonal temperatures. That could create burning opportunities over the weekend. The next weather system is forecast to approach the coast late Sunday and may bring some light rain to the valley by Monday afternoon. A weak ridge is forecast to build back over the region starting Tuesday afternoon. Tomorrow (18 Sep): AM Clouds...Mostly Sunny. 52/78 Fri (19 Sep): Mostly Cloudy. Slight Chance of a Shower...Mainly South. 50/75 Sat (20 Sep): Partly Cloudy. 50/75 Sun (21 Sep): Mostly Sunny. Increasing Clouds Late. 49/75 Mon (22 Sep): Increasing Chance of Light Rain and Cooler. 48/68 Tue (23 Sep): Partly Cloudy. Slight Chance of Showers. 48/70 Wed (24 Sep): Mostly Sunny. 47/72 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Sep 17 09:38:00 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 17 Sep 2008 11:38:00 -0500 Subject: [willamette-fcst] Forecast - Wednesday, September 17th, 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, September 17th, 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 ridge of high pressure that has been giving Oregon a late-summer hot spell is moving to the east and will allow a weak upper-level trough to move northward, across Oregon, today. That will destabilize the atmosphere and lead to thunderstorm development today...mainly from the Cascades eastward. South-southeasterly flow aloft is continuing to circulate California wildfire smoke over Oregon, so we will see a mix of clouds and hazy sunshine over the state today. The ODA surface analysis showed the surface thermal trough still over Western Oregon at mid-morning, but it is forecast to shift east of the Cascades by this afternoon. Increasing onshore flow should cap Willamette Valley temperatures in the low 80s this afternoon. The air aloft has cooled some since Tuesday morning, but mixing heights are forecast to remain below 2000 feet this morning and below 3000 feet until mid-afternoon. The upper-level trough will continue to cool the air aloft this afternoon with transport winds veering from southeasterly to southwesterly. Mixing heights should climb to near 4000 feet by late this afternoon. This transition may create an open burning opportunity for the mid-to-late afternoon period. However, there are some potential limiting factors. Southerly flow aloft may keep mixing heights suppressed below 3000 feet, and thundershower development over and east of the Cascades may not allow for good evacuation of smoke over the Cascades (poor gradient-stacking conditions). There is also a slight chance of a thundershower rolling off the Cascades into the Willamette Valley, because the flow above 10,000 feet is forecast to remain southeasterly today. Surface Winds: SW 5 this morning, SW 5-12 this afternoon. Transport Winds: SE 6 this morning, SW 9 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 36. High Temperature: Salem\'s high temperature today will be near 83. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 35%. Sunrise/Sunset: Salem sunset tonight: 7:18pm; sunrise tomorrow: 6:55am. Extended Outlook: Another upper-level low pressure system is forecast to approach the Northern California Coastline Thursday afternoon with increasing south-southwesterly flow aloft and continued onshore flow at the surface. This system should bring a little more cooling to Western Oregon with a slight chance of showers, as it comes onshore late Thursday and Friday. This system will likely bring showers to Southern and Eastern Oregon. It may also create favorable conditions for burning. A split-flow jet stream pattern is forecast by Saturday, with one branch to our south and the other to our north, leaving Oregon in a dry weather pattern with weak onshore flow making for seasonal temperatures. That could create burning opportunities over the weekend. The next weather system is forecast to approach the coast late Sunday and may bring some light rain to the valley by Monday afternoon. A ridge is forecast to begin building back over the region next Wednesday. Tomorrow (18 Sep): AM Clouds...Mostly Sunny. 52/78 Fri (19 Sep): Mostly Cloudy. Slight Chance of a Shower...Mainly South. 50/75 Sat (20 Sep): Partly Cloudy. 50/75 Sun (21 Sep): Mostly Sunny. Increasing Clouds Late. 49/75 Mon (22 Sep): Increasing Chance of Light Rain and Cooler. 48/68 Tue (23 Sep): Partly Cloudy. Slight Chance of Showers. 48/70 Wed (24 Sep): Mostly Sunny. 47/72 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Sep 17 08:04:26 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 17 Sep 2008 10:04:26 -0500 Subject: [willamette-fcst] Forecast - Wednesday, September 17th, 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, September 17th, 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 ridge of high pressure that has been giving Oregon a late-summer hot spell is moving to the east and will allow a weak upper-level trough to move northward, across Oregon, today. That will destabilize the atmosphere and lead to thunderstorm development today...mainly from the Cascades eastward. South-southeasterly flow aloft is continuing to circulate California wildfire smoke over Oregon, so we will see a mix of clouds and hazy sunshine over the state today. The ODA surface analysis showed the surface thermal trough still over Western Oregon at mid-morning, but it is forecast to shift east of the Cascades by this afternoon. Increasing onshore flow should cap Willamette Valley temperatures in the low 80s this afternoon. The air aloft has cooled some since Tuesday morning, but mixing heights are forecast to remain below 2000 feet this morning and below 3000 feet until mid-afternoon. The upper-level trough will continue to cool the air aloft this afternoon with transport winds veering from southeasterly to southwesterly. Mixing heights should climb to near 4000 feet by late this afternoon. This transition may create an open burning opportunity for the mid-to-late afternoon period. However, there are some potential limiting factors. Southerly flow aloft may keep mixing heights suppressed below 3000 feet, and thundershower development over and east of the Cascades may not allow for good evacuation of smoke over the Cascades (poor gradient-stacking conditions). There is also a slight chance of a thundershower rolling off the Cascades into the Willamette Valley, because the flow above 10,000 feet is forecast to remain southeasterly today. Surface Winds: SW 5 this morning, SW 5-12 this afternoon. Transport Winds: SE 6 this morning, SW 9 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 36. High Temperature: Salem\'s high temperature today will be near 83. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 35%. Sunrise/Sunset: Salem sunset tonight: 7:18pm; sunrise tomorrow: 6:55am. Extended Outlook: Another upper-level low pressure system is forecast to approach the Northern California Coastline Thursday afternoon with increasing south-southwesterly flow aloft and continued onshore flow at the surface. This system should bring a little more cooling to Western Oregon with a slight chance of showers, as it comes onshore late Thursday and Friday. This system will likely bring showers to Southern and Eastern Oregon. It may also create favorable conditions for burning. A split-flow jet stream pattern is forecast by Saturday, with one branch to our south and the other to our north, leaving Oregon in a dry weather pattern with weak onshore flow making for seasonal temperatures. That could create burning opportunities over the weekend. The next weather system is forecast to approach the coast late Sunday and may bring some light rain to the valley by Monday afternoon. A ridge is forecast to begin building back over the region next Wednesday. Tomorrow (18 Sep): AM Clouds...Mostly Sunny. 52/78 Fri (19 Sep): Mostly Cloudy. Slight Chance of a Shower...Mainly South. 50/75 Sat (20 Sep): Partly Cloudy. 50/75 Sun (21 Sep): Mostly Sunny. Increasing Clouds Late. 49/75 Mon (22 Sep): Increasing Chance of Light Rain and Cooler. 48/68 Tue (23 Sep): Partly Cloudy. Slight Chance of Showers. 48/70 Wed (24 Sep): Mostly Sunny. 47/72 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Sep 17 10:38:14 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 17 Sep 2008 10:38:14 -0700 Subject: [willamette-fcst] (no subject) Message-ID: Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, September 17th, 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 ridge of high pressure that has been giving Oregon a late-summer hot spell is moving to the east and will allow a weak upper-level trough to move northward, across Oregon, today. That will destabilize the atmosphere and lead to thunderstorm development today...mainly from the Cascades eastward. South-southeasterly flow aloft is continuing to circulate California wildfire smoke over Oregon, so we will see a mix of clouds and hazy sunshine over the state today. The ODA surface analysis showed the surface thermal trough still over Western Oregon at mid-morning, but it is forecast to shift east of the Cascades by this afternoon. Increasing onshore flow should cap Willamette Valley temperatures in the low 80s this afternoon. The air aloft has cooled some since Tuesday morning, but mixing heights are forecast to remain below 2000 feet this morning and below 3000 feet until mid-afternoon. The upper-level trough will continue to cool the air aloft this afternoon with transport winds veering from southeasterly to southwesterly. Mixing heights should climb to near 4000 feet by late this afternoon. This transition may create an open burning opportunity for the mid-to-late afternoon period. However, there are some potential limiting factors. Southerly flow aloft may keep mixing heights suppressed below 3000 feet, and thundershower development over and east of the Cascades may not allow for good evacuation of smoke over the Cascades (poor gradient-stacking conditions). There is also a slight chance of a thundershower rolling off the Cascades into the Willamette Valley, because the flow above 10,000 feet is forecast to remain southeasterly today. Surface Winds: SW 5 this morning, SW 5-12 this afternoon. Transport Winds: SE 6 this morning, SW 9 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 36. High Temperature: Salem\'s high temperature today will be near 83. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 35%. Sunrise/Sunset: Salem sunset tonight: 7:18pm; sunrise tomorrow: 6:55am. Extended Outlook: Another upper-level low pressure system is forecast to approach the Northern California Coastline Thursday afternoon with increasing south-southwesterly flow aloft and continued onshore flow at the surface. This system should bring a little more cooling to Western Oregon with a slight chance of showers, as it comes onshore late Thursday and Friday. This system will likely bring showers to Southern and Eastern Oregon. It may also create favorable conditions for burning. A split-flow jet stream pattern is forecast by Saturday, with one branch to our south and the other to our north, leaving Oregon in a dry weather pattern with weak onshore flow making for seasonal temperatures. That could create burning opportunities over the weekend. The next weather system is forecast to approach the coast late Sunday and may bring some light rain to the valley by Monday afternoon. A ridge is forecast to begin building back over the region next Wednesday. Tomorrow (18 Sep): AM Clouds...Mostly Sunny. 52/78 Fri (19 Sep): Mostly Cloudy. Slight Chance of a Shower...Mainly South. 50/75 Sat (20 Sep): Partly Cloudy. 50/75 Sun (21 Sep): Mostly Sunny. Increasing Clouds Late. 49/75 Mon (22 Sep): Increasing Chance of Light Rain and Cooler. 48/68 Tue (23 Sep): Partly Cloudy. Slight Chance of Showers. 48/70 Wed (24 Sep): Mostly Sunny. 47/72 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 18 08:05:53 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 18 Sep 2008 10:05:53 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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: Thursday, September 18th, 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: A weak upper-level disturbance turned the flow aloft southeasterly Wednesday and carried smoke from Oregon Cascade wildfires over the Willamette Valley. That system moved into Idaho overnight with onshore flow ushering in a shallow layer of cooler marine air into the valley. Willamette Valley nephelometer readings dropped considerably overnight...indicating improved air quality. The Salem sounding this morning showed that the flow aloft had become south-southeasterly again this morning, in response to an approaching weather system about 200 miles off the Southern Oregon Coast. That may direct more wildfire smoke over Western Oregon today. However, computer models forecast the flow aloft to turn more southerly this aftenoon, which may keep the bulk of the wildfire smoke east of the Willamette Valley. Low-level onshore flow overnight was strong enough to push coastal low clouds inland across the Willamette Valley. Satellite imagery showed low clouds extending from the coast to the west slopes of the Cascades. Based on surface and pilot reports, the low clouds are only about 1500 feet thick, with clouds tops below 3500 feet. That would imply an early afternoon break-out into sunshine with temperatures recovering into the mid 70s. Cooler air aloft and forecast southwesterly transport winds may improve ventilation conditions enough for limited open burning this afternoon. Surface Winds: Var 0-4 this morning, SW 5-10 this afternoon. Transport Winds: SW 5 this morning, SW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3700 feet. Ventilation index 26. High Temperature: Salem\'s high temperature today will be near 77. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 39%. Sunrise/Sunset: Salem sunset tonight: 7:16pm; sunrise tomorrow: 6:56am. Extended Outlook: The next weather system is forecast to move onto the Southern Oregon/Northern California Coastline aroudn midday Friday. It will likely spread some showers and possibly thundershowers from SW Oregon across much of Central and Eastern Oregon Friday and Friday night. There is a chance of shower activity making it as far north as the Willamette Valley Friday, but amounts would not be impressive. This system will further cool the air aloft, which has the potential to raise mixing heights, if precipitation stays south of the valley. Forecast south-southwesterly transport winds may allow for limited open burning. In the wake of the system Friday, strong onshore flow will likely bring a thicker marine layer into the Willamette Valley by Saturday morning. A drier westerly flow aloft should clear skies Saturday afternoon, but a deep marine layer and strong gradient-stacking may not allow for open burning. The next weather system is forecast to approach the coast late Sunday, which could create a burning opportunity Sunday afternoon, if the air mass stays dry enough. High pressure is forecast to build over the region starting Monday afternoon with the potential of a return to sunny and warm conditions during the middle of next week. Tomorrow (19 Sep): Mostly Cloudy. Slight Chance of a Shower...Mainly South. 50/75 Sat (20 Sep): Cloudy in the Morning. Afternoon Clearing. 51/72 Sun (21 Sep): Partly sunny. Increasing Cloudy Late. 49/74 Mon (22 Sep): Chance of Showers Early...Afternoon Clearing. 48/68 Tue (23 Sep): Beconing Mostly Sunny. 46/72 Wed (24 Sep): Sunny and Warmer. 45/82 Thu (25 Sep): Sunny and Warm. 47/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 18 12:53:48 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 18 Sep 2008 14:53:48 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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. SPECIAL UPDATE...Extended Preparatory burning until 4 pm with a 200 acre limit. Issued: Thursday, September 18th, 2008 at 1:30pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is allowed from now until 4:00pm with a 200 acre limit. Propane flaming is allowed from 12:00pm until 5:00pm. Stack burning is not allowed. Weather Discussion: A weak upper-level disturbance moved into Idaho overnight with onshore flow ushering cooler marine air into the valley. The Salem sounding this morning clearly showed the marine layer extending from the surface to about 3500 feet with south-southeasterly flow aloft. Visible satellite imagery showed low clouds had penetrated from the coast to the crest of the Cascades this morning. The ODA surface analysis showed that the thermal trough had just pushed far enough east, early this afternoon, to allow marine air to spill into Central Oregon via blustery west winds. Prior to that, the cool pool of air had already deepened, to over 4000 feet, in the Western Valleys. Low clouds were just starting to break up in the south valley at 1:30pm with some brightening of the sky in the north valley. With a mid to late-afternoon cloud break-up expected, high temperatures will likely only climb into the low 70s. Infrared satellite imagery showed clouds from an approaching weather system about 175 miles off the Southern Oregon Coast. That system appears to be forcing the retreat of the southern edge of the marine clouds in the Willamette Valley and will aid in their break-up this afternoon. With a deep marine layer in place over Western Oregon, gradient-stacking issues may inhibit open burning this afternoon. However, ventilation conditions have improved enough to allow for an expansion of preparatory burning. Surface Winds: SW 5-10 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 72. Humidities: Relative humidity drops to 50% by 4pm. Minimum relative humidity will be near 47%. Sunrise/Sunset: Salem sunset tonight: 7:16pm; sunrise tomorrow: 6:56am. Extended Outlook: The next weather system is forecast to move onto the Southern Oregon/Northern California Coastline around midday Friday. It will likely spread some showers and possibly thundershowers from SW Oregon across much of Central and Eastern Oregon Friday and Friday night. There is a chance of shower activity making it as far north as the Willamette Valley Friday, but amounts would not be impressive. This system will further cool the air aloft, which has the potential to raise mixing heights, if precipitation stays south of the valley. Forecast south-southwesterly transport winds may allow for limited open burning. In the wake of the system Friday, strong onshore flow will likely bring another marine layer into the Willamette Valley by Saturday morning. A drier westerly flow aloft should clear skies Saturday afternoon, but strong gradient-stacking may not allow for open burning. The next weather system is forecast to approach the coast late Sunday, which could create a burning opportunity Sunday afternoon. That system may bring a little rain to the valley Sunday night and early Monday. High pressure is forecast to build over the region, starting Monday afternoon, with the potential of warm conditions, with offshore flow, during the middle of next week. Tomorrow (19 Sep): Mostly Cloudy. Slight Chance of a Shower...Mainly South. 50/75 Sat (20 Sep): Cloudy in the Morning. Afternoon Clearing. 51/72 Sun (21 Sep): Partly sunny. Increasing Clouds Late. 49/74 Mon (22 Sep): Chance of Showers Early...Afternoon Clearing. 48/68 Tue (23 Sep): Becoming Mostly Sunny. 46/72 Wed (24 Sep): Sunny and Warmer. 45/82 Thu (25 Sep): Sunny and Warm. 47/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Sep 19 08:05:15 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 19 Sep 2008 10:05:15 -0500 Subject: [willamette-fcst] Forecast - Friday, September 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: Friday, September 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: An upper-level low presure system, just off the Northern California Coast this morning, with increasing the southerly flow aloft and sending more California and Oregon wildfire smoke over the region...making for hazy conditions. As that system moves onshore today, it will aid in the break-up of the marine low clouds over the Willamette Valley. However, even if the marine low clouds clear from the Willamette Valley this afteroon, skies will remain mostly cloudy. The sounding over Salem this morning showed a shallowing marine layer, now less than 3000 feet thick, with northeasterly transport winds. Increasing southerly winds are present above the marine layer with continued quite warm air aloft. A strong temperature inversion was present at the top of the marine layer with quite warm air between 3000 and 10,000 feet. That will keep mixing heights below 3000 feet until the air mass aloft begins cooling later this afternoon. Temperatures aloft support Willamette Valley highs climbing into the 80s this afternoon, but the combination of the low-level marine air and cloud-cover should hold valley highs in the low 70s. The ODA surface analysis showed a stalled thermal trough extending from East-Central Washington, through Central Oregon, to SW Oregon. It should finally progressed eastward today in response the the upper-level system coming onshore. Scattered showers are likely, with a possible thundershower, from SW Oregon across Central and Eastern Oregon later today and tonight, as the weather system slowly pushes eastward across Southern Oregon. It does not appear that showers will make it as far north as the Willamette Valley, but that possibility can not be entirely ruled out...especially for the south valley. Cooler air aloft and northwesterly transport winds are forecast for Western Oregon later this afternoon. If surface temperatures warm enough this afternoon, mixing heights could reach 4000 feet or higher. Therefore, it is possible, although unlikely, that ventilation conditions could improve enough to allow for limited open burning this afternoon. We plan to monitor the changing conditions this afternoon. Surface Winds: Var 0-5 this morning, NW 4-8 this afternoon. Transport Winds: NE 9 this morning, NW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 41. High Temperature: Salem\'s high temperature today will be near 72. Humidities: Relative humidity drops to 50% by 3pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 7:14pm; sunrise tomorrow: 6:57am. Extended Outlook: Onshore flow is likely Friday night and Saturday, as the upper-level low pressure suystem moves across Eastern Oregon and into Idaho. That should bring a solid deck of marine low clouds back into the Willamette Valley Saturday morning. A more westerly flow aloft should finally help to clear the wildfire smoke from Western Oregon by Saturday afternoon. Some afternoon sunshine is possible, as the marine clouds break-up. If there is enough surface warming, mixing heights and transport winds may be sufficient to allow for limited open burning in the late afternoon, but that is unlikely. A transitory ridge is forecast to move over Western Oregon Saturday night with the next weather system, in westerly flow aloft, forecast to approach the Sunday afternoon. That system has the potential to create a burning opportunity Sunday, if the air mass is able to warm enough ahead of it. The timing of that system and the amount of marine air already in the valley makes that questionable. Some light showers are possible, beginning Sunday, through Monday, as a stronger upper-level trough moves over the state, via the westerly flow aloft. Total rainfall amounts are forecast to be less than one-tenth of an inch with the greatest chance of rain in the north valley near the Cascade Foothills. High pressure is forecast to build over the region Tuesday with the onshore flow turning more northerly in the afternoon. It appears that the upper-level ridge will strengthen over the region Wednesday for continued warming and drying of the air mass. Transport winds will likely be northerly and may become offshore. The ridge is forecast to weaken, by some of the long-range computer models, late next week with the possibility of a weather system creating a burning opportunity by Friday. However, that is getting beyond the scope of the weather forecast models this time of the year. Tomorrow (20 Sep): Cloudy in the Morning. Partial Afternoon Clearing. 51/72 Sun (21 Sep): Mostly Cloudy. Increasing Chance of Light Showers. 51/70 Mon (22 Sep): Mostly Cloudy. Chance of Showers and Cool. 48/65 Tue (23 Sep): Becoming Partly Cloudy in the Afternoon. 45/71 Wed (24 Sep): Sunny and Warmer. 47/78 Thu (25 Sep): Sunny and Warm. 48/78 Fri (26 Sep): Increasing Clouds and Cooler. 49/72 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Sat Sep 20 11:56:45 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Sat, 20 Sep 2008 13:56:45 -0500 Subject: [willamette-fcst] Forecast - Saturday, September 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: Saturday, September 20th, 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: An upper-level low pressure system moved across Southern Oregon overnight and was centered over SE Oregon this morning. The system brought mostly cloudy skies to Washington and Oregon overnight. The counter-clockwise circuation around this system brought showers to Southwest, Central, and Eastern Oregon, as well as much of Washington state. Showers were continuing this morning from SE Oregon through North-Central Oregon, into Washington. Only some sprinkles were reported over NW Oregon, near the Cascade foothills. Skies were beginning to clear late this morning along the Oregon Coast, with some breaks in the clouds showing up in the Willamette Valley. Valley temperature were in the upper 50s and low 60s. The flow aloft will become westerly today, in the wake of the existing low pressure system. The Salem sounding this morning showed cooler air aloft and more cooling aloft is expected this afternooon. The ODA surface analysis showed high pressure centered over the Southern Oregon Coast with onshore flow across most of the state. Pressure gradients show some unfavorable stacking at midday, but that may improve enough, with daytime heating, to allow for open burning later this afternoon. The wildfire smoke, that has been over Western Oregon for several days, should also start to get evacuted this afternoon. Partly sunny skies are forecast this afternoon with valley temperatures approaching 70 degrees. Mixing heights should climb to near 3000 feet, when surface temperatures reach about 65 degrees and may climb to near 4500 feet later this afternoon, if there is enough surface heating. We will begin taking pibal readings right after the noon radio broadcast. Surface Winds: SW 5-10...becoming W 5-10 later this afternoon. Transport Winds: SW 7...becoming SW 9 later this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 41. High Temperature: Salem\'s high temperature today will be near 69. Humidities: Relative humidity drops to 50% by 4pm. Minimum relative humidity will be near 47%. Sunrise/Sunset: Salem sunset tonight: 7:12pm; sunrise tomorrow: 6:59am. Extended Outlook: The next weather system, in westerly flow aloft, forecast to approach the coastline Sunday afternoon. That system has the potential to create another burning opportunity Sunday, if showers do not move onshore too early in the day and the air mass is able to warm enough ahead of it. Some light showers are likely, in the north valley, by Sunday evening, as an upper-level trough moves over the state. Total rainfall amounts are forecast to be less than one-tenth of an inch with the greatest chance of rain in the north valley, near the Cascade Foothills, Sunday night and early Monday morning. High pressure is forecast to build over the region Monday afternoon, with the onshore flow turning more northerly. The long-range models have changed their tune again and are now forecasting another system to move onshore Tuesday evening. That system may create another burning opportunity, ahead of it, Tuesday afternoon. The valley could pick up one-tenth of an inch, or more, Wednesday...especially in the north. Westerly flow aloft is forecast to continue Thursday with onshore flow at the surface keeping lots of marine clouds over the valley but no rainfall. The flow aloft is forecast to turn southwesterly Friday, which may create another burning opportunity Friday afternoon. A weak weather system may bring more showers to the Willamette Valley Saturday. Tomorrow (21 Sep): Mostly Cloudy. Increasing Chance of Showers...Mainly North. 49/68 Mon (22 Sep): Chance of Showers Early...Mainly North. Becoming Partly Sunny. 46/65 Tue (23 Sep): Increasing Clouds. Chance of Rain Late. 45/73 Wed (24 Sep): Cloudy and Cool. Good Chance of Rain. 47/66 Thu (25 Sep): Morning Clouds. Partly Sunny in the Afternoon. 48/70 Fri (26 Sep): Partly Sunny. Increasing Clouds Late. 45/71 Sat (27 Sep): Mostly Cloudy. Chance of Showers. 49/65 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Sun Sep 21 11:05:38 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Sun, 21 Sep 2008 13:05:38 -0500 Subject: [willamette-fcst] Forecast - Sunday, September 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: Sunday, September 21st, 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: Westerly flow aloft began clearing the wildfire smoke from Western Oregon Saturday with some very light showers falling late Saturday through early this morning. Rainfall amounts were generally less than .05 inches across the Willamette Valley. The greatest amounts were in the north valley near the cascade Foothills. There were a couple of reports of just less than one-tenth of an inch near Stayton. Westerly flow aloft will continue today with a cool upper-level trough over Washington and Oregon. Doppler radar showed another area of light showers moving east of the I5 corridor in Northern Marion and Southwestern Clackamas Counties. There were also scattered very light showers showing up in Eastern Linn County. There appeared to be a significant break in the shower activity from I5 westward to offshore, with spotty breaks in the cloud-cover showing up on satellite imagery and surface reports. That may allow time for fields to dry early this afternoon and for surface temperatures to warm into the mid 60s. The Salem sounding this morning showed cooling below 4000 feet, compared wtih Saturday, so mixing heights should climb above 3000 feet, when surface temperatures reach about 62 degrees. Transport winds were southwesterly this morning and are forecast to slowly veer to westerly early this afternoon...eventually becoming northwesterly this evening. The ODA surface analysis showed high pressure centered over the Southern Oregon Coast with onshore flow across most of Oregon...although weaker than on Saturday. There is some gradient-stacking that would need to be compensated for, with daytime heating, to insure good ventilation conditions for burning. If we do get a break from the shower activity, and some surface warming, there may be a brief burning opportunity, for dry fields, in the mid-afternoon period. The best chance for that will be in the south valley, where only a couple hundredths of an inch of rain fell. Daytime heating may promote an increase in the shower activity late this afternoon, and that will need to be closely monitored. Open burning is not advised near showers, due upredictable transport winds and potential down-mixing of smoke. There is a chance of showers through Monday morning, mainly in the north valley, as a weak upper-level disturbance moves across Western Washington. Surface Winds: S 5-10 at midday...becoming W 5-10, then NW 5-15 late this afternoon. Transport Winds: SW 10 at midday...becoming W 10 this afternoon and NW 10 this evening. 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 65. Humidities: Minimum relative humidity will be near 54%. Sunrise/Sunset: Salem sunset tonight: 7:10pm; sunrise tomorrow: 7:00am. Extended Outlook: High pressure is forecast to build over the region Monday afternoon, with the flow aloft becoming northwesterly and the surface flow turning more northerly. Transport winds may stay northwesterly, in the north valley, but fields may be too damp for any burning. A trasitory ridge of high pressure is forecast for Tuesday wtih the next weather system being delayed until Wednesday afternoon. There may be a burning opportunity ahead of that system Tuesday and/or Wednesday. The valley could pick up one-tenth of an inch of rain Wednesday afternoon through Thursday morning...especially in the north. Westerly flow aloft is forecast to continue Thursday with onshore flow at the surface keeping lots of marine clouds over the valley, but rainfall should taper off after the early morning. The long-range models differ on the strength and timing of a weak system that may move onshore Friday. That could be another burning opportunity but is way too far out to call. A ridge is now forecast to build over the region for the weekend, but that is getting beyond where I trust the models, which have been flip-flopping around like a fresh-caught trout. Tomorrow (22 Sep): Chance of Showers Early...Mainly North. Becoming Partly Sunny. 46/65 Tue (23 Sep): Mostly Sunny. 43/73 Wed (24 Sep): Cloudy and Cooler. Increasing Chance of Rain. 50/66 Thu (25 Sep): Morning Clouds/Drizzle. Partly Sunny in the Afternoon. 50/73 Fri (26 Sep): Partly Sunny. Increasing Clouds late. 47/74 Sat (27 Sep): Becoming Partly Sunny. 48/74 Sun (28 Sep): Partly Cloudy. 46/75 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Sep 22 08:03:05 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 22 Sep 2008 10:03:05 -0500 Subject: [willamette-fcst] Forecast - Monday, September 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: Monday, September 22nd, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 1:00pm until 6:30pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed from 1:00pm until 6:30pm. Weather Discussion: Summer finished on a damp note with most of the Willamette Valley picking up between one-tenth and one-quarter inch of rain overnight. Autumn officially began this mornig at 8:44am. Morning satellite imagery showed cloudy skies over the Willamtte Valley with what appeared to be the southern end of a dissipating cold front moving across NW Oregon. Doppler radar showed areas of light rain over the eastern valley with a few showers rolling onshore in the wake of the weak cold front. The ODA surface analysis showed high pressure building into the Central Oregon Coast with weak onshore pressure gradients across the Willamette Valley. A cool upper-level trough will swing over NW Oregon this morning with a few more showers likely...mainly in the north. It will slide east of the region this afternoon with the flow aloft drying out and becoming northwesterly. Showers will taper off this afternoon with a few sunbreaks. Temperatures will be below normal with highs in the mid 60s. Fields will need time to dry before they can be burned. Cool air aloft will help mixing heights climb to near 5000 feet this afternoon. Transport winds will likely stay northwesterly, in the north valley, which will allow for the burning of dry stacks, from Albany northward. Transport winds are forecast to become northerly this afternoon south of Albany. The cool air mass will continue to dry overnight with partial clearing allowing valley temperatures to drop into the low 40s by Tuesday morning. Surface Winds: Light this morning, NW 5-12 Albany North...N 8-15 South of Albany this afternoon. Transport Winds: NW 6 this morning, NW 10 Albany north...N 10 South of Albany 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 65. Humidities: Relative humidity drops to 50% by 4pm. Minimum relative humidity will be near 45%. Sunrise/Sunset: Salem sunset tonight: 7:08pm; sunrise tomorrow: 7:01am. Extended Outlook: A transitory ridge of high pressure is forecast to bring some sunshine early Tuesday with middle and high clouds increasing late, from the the next weather system, in a westerly flow aloft. The lastest computer model guidance is suggesting that transport winds may become favorable for burning by late Tuesday but more likely Wednesday. The models are generally holding off the rain until late Wednesday, which would allow for burning Wednesday afternoon. Damp fields may require fluffing to take advantage of this potential burning opportunity. An upper-level trough will keep a chance of showers in the forecast through Thursday evening...with most of the rain in the north valley. Another one-tenth to one-quarter of an inch of rain is possible from late Wednesday through Thursday...especially on the east side of the north valley. Showers should taper off by Thursday evening. A weak upper-level trough is forecast to approach the coastline Friday, which may create another burning opportunity Friday afternoon. The long-range models are coming into agreement on building a ridge of high pressure over the Pacific Northwest this weekend. The low-level winds are forecast to become northerly by Saturday afternoon and perhaps offshore by Sunday, which would bring increasing amounts of sunshine and near to above normal temperatures. That pattern would effectively dry any remaining damp fields in preparation for a burn opportunity around Wednesday of next week. Tomorrow (23 Sep): Partly Cloudy. Increasing High Clouds in the Afternoon. 41/71 Wed (24 Sep): Mostly Cloudy. Increasing Chance of Light Rain. 47/71 Thu (25 Sep): Chance of Showers...Decreasing Late. 50/68 Fri (26 Sep): Mostly Cloudy. Increasing Chance of Showers. 48/73 Sat (27 Sep): Becoming Mostly Sunny in the Afternoon. 48/73 Sun (28 Sep): Sunny and Warmer. 47/77 Mon (29 Sep): Sunny and Warm. 47/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Sep 22 08:14:57 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 22 Sep 2008 10:14:57 -0500 Subject: [willamette-fcst] Forecast - Monday, September 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. ...Corrected Stack Burning Areas... Issued: Monday, September 22nd, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 1:00pm until 6:30pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed, for dry stacks, from Albany northward from 1:00pm until 6:30pm. Straw stack burning is not allowed south of Albany. Weather Discussion: Summer finished on a damp note with most of the Willamette Valley picking up between one-tenth and one-quarter inch of rain overnight. Autumn officially began this mornig at 8:44am. Morning satellite imagery showed cloudy skies over the Willamtte Valley with what appeared to be the southern end of a dissipating cold front moving across NW Oregon. Doppler radar showed areas of light rain over the eastern valley with a few showers rolling onshore in the wake of the weak cold front. The ODA surface analysis showed high pressure building into the Central Oregon Coast with weak onshore pressure gradients across the Willamette Valley. A cool upper-level trough will swing over NW Oregon this morning with a few more showers likely...mainly in the north. It will slide east of the region this afternoon with the flow aloft drying out and becoming northwesterly. Showers will taper off this afternoon with a few sunbreaks. Temperatures will be below normal with highs in the mid 60s. Fields will need time to dry before they can be burned. Cool air aloft will help mixing heights climb to near 5000 feet this afternoon. Transport winds will likely stay northwesterly, in the north valley, which will allow for the burning of dry stacks, from Albany northward. Transport winds are forecast to become northerly this afternoon south of Albany. The cool air mass will continue to dry overnight with partial clearing allowing valley temperatures to drop into the low 40s by Tuesday morning. Surface Winds: Light this morning, NW 5-12 Albany North...N 8-15 South of Albany this afternoon. Transport Winds: NW 6 this morning, NW 10 Albany north...N 10 South of Albany 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 65. Humidities: Relative humidity drops to 50% by 4pm. Minimum relative humidity will be near 45%. Sunrise/Sunset: Salem sunset tonight: 7:08pm; sunrise tomorrow: 7:01am. Extended Outlook: A transitory ridge of high pressure is forecast to bring some sunshine early Tuesday with middle and high clouds increasing late, from the the next weather system, in a westerly flow aloft. The lastest computer model guidance is suggesting that transport winds may become favorable for burning by late Tuesday but more likely Wednesday. The models are generally holding off the rain until late Wednesday, which would allow for burning Wednesday afternoon. Damp fields may require fluffing to take advantage of this potential burning opportunity. An upper-level trough will keep a chance of showers in the forecast through Thursday evening...with most of the rain in the north valley. Another one-tenth to one-quarter of an inch of rain is possible from late Wednesday through Thursday...especially on the east side of the north valley. Showers should taper off by Thursday evening. A weak upper-level trough is forecast to approach the coastline Friday, which may create another burning opportunity Friday afternoon. The long-range models are coming into agreement on building a ridge of high pressure over the Pacific Northwest this weekend. The low-level winds are forecast to become northerly by Saturday afternoon and perhaps offshore by Sunday, which would bring increasing amounts of sunshine and near to above normal temperatures. That pattern would effectively dry any remaining damp fields in preparation for a burn opportunity around Wednesday of next week. Tomorrow (23 Sep): Partly Cloudy. Increasing High Clouds in the Afternoon. 41/71 Wed (24 Sep): Mostly Cloudy. Increasing Chance of Light Rain. 47/71 Thu (25 Sep): Chance of Showers...Decreasing Late. 50/68 Fri (26 Sep): Mostly Cloudy. Increasing Chance of Showers. 48/73 Sat (27 Sep): Becoming Mostly Sunny in the Afternoon. 48/73 Sun (28 Sep): Sunny and Warmer. 47/77 Mon (29 Sep): Sunny and Warm. 47/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Sep 23 07:55:12 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 23 Sep 2008 09:55:12 -0500 Subject: [willamette-fcst] Forecast - Tuesday, September 23rd, 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, September 23rd, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 2:00pm until 6:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A transitory ridge of high pressure is forecast to bring some sunshine and warmer temperatures to Oregon today. Willamette valley highs should climb int the low 70s, which is still slightly below aferage but much warmer than the mid 60s we saw Monday afternoon. The sounding over Salem this morning showed considerable warming above 3500 feet compared with Monday morning and more warming aloft is forecast today. That will cap afternoon mixing heights near 3500. Forecast northerly transport winds this afternoon makes open burning unlikely. The ODA surface analysis showed a weak thermal trough trying to build northward, across Western Oregon, in reponse to transitory upper-level ridge moving over the state. Pressure gradients were weak northerly across the Western Oregon this morning with a slight offshore component. Clearing skies overnight allowed temperatures to drop to their lowest values since last spring for many Western Oregon locations. Hillsboro dipped to at least 36 degrees this morning, and Eugene dropped to 37. McMinnville was not much warmer at 38. Recent rains and cool surface temperatures helped create areas of shallow valley fog this morning, but it should be short-lived this morning. Infrared satellite imagery showed an impressive-looking cloud-shield from an approaching weather system about 300 miles offshore at mid-morning. Some middle and high clouds, from this system, had already advanced onshore and over the Willamette Valley this morning. The latest computer models speed up the timing of this system, which does not bode well for creating a burning opportunity. It will likely stay too far offshore today, with transport winds remaining northerly and the air aloft staying too warm. By Midday Wednesday, it may be too close, with stong southwesterly winds near the surface and rain moving into the Willamette Valley. The best chance for a burning opportunity will be in the early afternoon Wednesday, if the winds stay weak enough and the rain has not moved onshore by that time. Fluffing of damp fields would be required to take advantage of this potential burning opportunity. It is looking more likely, however, that the timing of this system will not allow for a burning opportunity. We will monitor transport winds this afternoon for the unlikely event that they react early to the approaching storm and turn more westerly. That is not forecast to happen until around sundown or shortly thereafter. Surface Winds: NNE 5-10 this morning, NNE 5-10 this afternoon. Transport Winds: NE 10 this morning, N 7 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 71. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 38%. Sunrise/Sunset: Salem sunset tonight: 7:07pm; sunrise tomorrow: 7:02am. Extended Outlook: Computer models had been holding off rain until late Wednesday, which may have allowed for a burning opportunity Wednesday afternoon. However, the latest guidance is suggesting that light rain will move into the Northern Willamette Valley as early as tomorrow morning with rain slowly spreading south during the afternoon. The associated upper-level trough should maintani a little shower activity through Thursday...mainly in the north valley. Interestingly, the bulk of the rain from this storm is forecast to stay north of Oregon with only about one-tenth of an inch projected to fall in the Willamette Valley. This system has entrained some tropical moisture, and will produce impressive low-level southwesterly winds, so I suspect total rainfall amounts will be closer to one-quarter of an inch in the upslope regions of the north valley, near the Cascade Foothills. The weak upper-level trough that was forecast to approach the coastline Friday now appears as if it will stay north of the region, with weak westerly flow aloft. However, it may come close enough to turn transport winds onshore and create a burning opportunity, for dry fields, Friday afternoon. The long-range models are still forecasting a stronger ridge of high pressure to build over the Pacific Northwest beginning Saturday with a return to above normal temperatures. Weak west-northwesterly flow aloft is forecast Saturday. The upper-level ridge to forecast to amplify just east of the region Sunday, putting Western Oregon under weak southwesterly flow aloft with possible offshore flow at the surface. The upper-level ridge is forecast to slowly slide eastward, early next week, with a series of weather systems coming onshore beginning as early as late Monday. This transition may bring another burning opportunity early next week, and then there is every indication that the 2008 burn season will come to a wet conclusion. Tomorrow (24 Sep): Cloudy and Blustery with Rain Spreading South During the Day. 48/69 Thu (25 Sep): Mostly Cloudy North with a Chance of Showers. Partly Cloudy South. 50/67 Fri (26 Sep): Partly Sunny. 46/73 Sat (27 Sep): Partly Sunny. 47/76 Sun (28 Sep): Sunny and Warm. 47/80 Mon (29 Sep): Increasing Clouds. 48/77 Tue (30 Sep): Increasing Chance of Rain. 49/69 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Sep 24 08:03:13 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 24 Sep 2008 10:03:13 -0500 Subject: [willamette-fcst] Forecast - Wednesday, September 24th, 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, September 24th, 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 warm front was bringing some light rain to portions of NW Washington this morning, while Western Oregon was enjoying a touch of sunshine. A weakening cold front, less than 200 miles offshore, will move onshore this evening...likely spreading some light rain inland across the Willamette Valley. High temperatures should climb into the upper 60s, ahead of the cold front, this afternoon. The ODA surface analysis showed low pressure offshore and high pressure over the Southern Oregon Coast combining to create south-southeasterly gradients across the Willamette Valley. Gradients should turn more southerly and increase later this afternoon. Ventilation conditions may provide a burning opportunity this afternoon. However, transport winds may be to brisk and/or to southerly to allow for burning. The Salem sounding this morning showed south-southwesterly transport winds and fairly warm air aloft. Some cooling aloft is forecast by early this afternoon, which may combine with surface heating to raise mixing heights to 3000 feet. If the cooling aloft does not occur in time, mixing heights may also be a limiting factor for any burning today. We will begin pibal readings at 11am to monitor the transport winds. The cold front is forecast to sweep across the Willamette Valley tonight. Rainfall amounts with this system do not look overly imperssive and may not exceed one-tenth of an inch for much of the valley...especially south. Surface Winds: S 5-15 this morning, SW 10-20 this afternoon. Transport Winds: S 15 this morning, SSW 20 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 60. High Temperature: Salem\'s high temperature today will be near 68. Humidities: Minimum relative humidity will be near 47%. Sunrise/Sunset: Salem sunset tonight: 7:05pm; sunrise tomorrow: 7:03am. Extended Outlook: An upper-level trough should maintain a little shower activity through Thursday...mainly in the north valley. The bulk of the rain from this storm is forecast to stay north of Oregon with total rainfall amounts of about one-tenth of an inch projected to fall in the Nothern Willamette Valley and possibly less in the south valley. If the south valley happens to stay dry enough, transport winds may become favorable for burning there Thursday, as the upper-level trough passes by to the north. A weak upper-level trough is forecast to turn the flow aloft southwesterly Friday and may create a late-afternoon burning opportunity for dry fields. The system will move into Southern British Columbia early Saturday with the bulk of the precipitation forcast to stay north of Oregon. There may be a light shower in the extreme north valley Saturday morning, but the odds favor dry weather. Depending on the timing and strength of that system, it may also create a burning opportunity Saturday. That is too far out to call at this time. The long-range models are still forecasting an upper-level ridge to amplify, just east of the region Sunday, putting Western Oregon under weak southwesterly flow aloft with possible offshore flow at the surface. The ridge is forecast to slowly slide eastward, early next week, with a series of weather systems coming onshore about mid-week. This transition may bring another burning opportunity, although the transport winds may be to southerly. It appears that a parade of increasingly wet systems will move onshore late next week, which would mark the end of the 2008 burn season. Thu (25 Sep): Mostly Cloudy North with a Chance of Showers. Partly Sunny South. 52/67 Fri (26 Sep): Mostly Sunny. 45/75 Sat (27 Sep): Partly Sunny. Slight Chance of a Shower Extreme North Valley. 47/73 Sun (28 Sep): Sunny and Warm. 47/80 Mon (29 Sep): Mostly Sunny and Warm. 48/80 Tue (30 Sep): Increasing Clouds. Chance of Rain Late. 50/73 Wed (01 Oct): Light Rain Likely. 48/66 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Sep 25 08:01:34 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 25 Sep 2008 10:01:34 -0500 Subject: [willamette-fcst] Forecast - Thursday, September 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: Thursday, September 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: A slow-moving cold front dropped generally from one-tenth to one-third of an inch of rain across most of the Willamette Valley Wednesday evening. Heavier amounts fell in some of the Cascade Foothills. An upper-level trough will maintain a chance of showers today...mainly in the north valley. Temperatures will be cooler today with valley highs in the 65-70 degree range. Satellite imagery showed the low-pressure center near Vancouver Island, British Columbia this morning with the cold front moving across Eastern Oregon. There were some breaks in the overcast west of the Cascades with Doppler radar indicating a few light showers north of about Salem. Valley temperatures were running in the low to mid 50s with south to southwest winds 5-10 mph. The Salem sounding showed considerable cooling aloft since Wednesday, so mixing heights should climb to 3000 feet when surface temperatures warm to about 64 degrees and climb as high as 4000 feet this afternoon, due to the passage of a cool upper-level trough to our north. Transport winds are forecast to be west-southwesterly this afternoon and much lighter than yesterday, so ventilation conditions may be conducive to allow for open burning of dry fields. Fluffing of damp fields is required to take advantage of this potential burning opportunity. Surface Winds: SW 5-15 this morning, W 5-15 this afternoon. Transport Winds: SW 13 this morning, WSW 10 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 67. Humidities: Minimum relative humidity will be near 54%. Sunrise/Sunset: Salem sunset tonight: 7:03pm; sunrise tomorrow: 7:05am. Extended Outlook: A weaker upper-level trough is forecast to approach the Southern British COlubia Coast late Friday with westerly flow aloft over Oregon. That may may create a late-afternoon burning opportunity for dry fields, but forecast soundings indicate that low-level winds may be too northerly. The system will move into Southern British Columbia early Saturday with precipitation forecast to stay mostly north of Oregon. It could produce some sprinkles or light showers in the extreme north valley. Depending on the timing and strength of that system, it may also create a burning opportunity Saturday afternoon, but forecast soundings are calling for northerly low-level winds returning by Saturday afternoon. The long-range models are still forecasting an upper-level ridge to amplify over Eastern Oregon and Idaho Sunday, putting Western Oregon under weak southwesterly flow aloft. Offshore surface flow and warmer air aloft may help valley temperatures approach 80 degrees, which will aid in the drying of damp fields. The ridge is forecast to slowly slide eastward, early next week, opening the door for a series of progressively wetter weather systems to come onshore beginning late Tuesday or Wednesday. This transition may create a burning opportunity about Tuesday or Wednesday of next week, if transport winds are not too southerly. The outlook is for wet conditions late next week and beyond. Tomorrow (26 Sep): Mostly Sunny. 45/75 Sat (27 Sep): Mostly Sunny. 46/76 Sun (28 Sep): Sunny and Warm. 46/81 Mon (29 Sep): Increasing High Clouds and Warm. 49/82 Tue (30 Sep): Increasing Clouds. 50/76 Wed (01 Oct): Mostly Cloudy. Increasing Chance of Rain. 51/69 Thu (02 Oct): Rain Likely. 50/66 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Sep 26 08:05:01 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 26 Sep 2008 10:05:01 -0500 Subject: [willamette-fcst] Forecast - Friday, September 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: Friday, September 26th, 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 transitory ridge of high pressure moved over Oregon last night and allowed skies to clear. Cool temperatures and moisture from recent rains combined to help areas of fog form in the Willamette Valley this morning. Valley temperatures locally dropped into the upper 30s early this morning with Corvallis dipping briefly to 37 degrees. Visible satellite imagery showed fairly extensive fog and low clouds in the Willamette Valley at mid-morning with patchy fog along the coast. The remainder of the state had mostly sunny skies. Mid-morning valley temperatures were mostly in the 40s. The Salem sounding this morning showed a dry offshore flow, just above the fog layer, which will help evaporate the fog later this morning. The air aloft has warmed considerably since Thursday afternoon, so mixing heights will stay below 3000 feet until well into the afternoon. It will be warmer today on the surface, as well, with afternoon highs in the low to mid 70s. A weakening cold front is approaching the Washington and Northern Oregon Coast and was already spreading some hig clouds across Western Washington and Northwest Oregon. It should cool the air aloft enough to raise mixing heights above 3000 feet by late this afternoon. It will also likely back the northeastely transport winds to northwesterly. That combination of weather factors would effectively evacuate smoke from the valley. This afternoon may be an opportunity to burn remaining dry fields...especially in the north valley. Wet fields will need fluffing. Surface Winds: N 5-10 this morning, NW 7-12 this afternoon. Transport Winds: NE 10 this morning, NW 9 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 73. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 41%. Sunrise/Sunset: Salem sunset tonight: 7:01pm; sunrise tomorrow: 7:06am. Extended Outlook: An upper-level trough will move into Southern British Columbia early Saturday with the trailing weak cold front likely bringing a little rain to Western Washington and perhaps some sprinkles as far south as the Northern Oregon Coast. No rain is forecast, from this system, in the Willamette Valley. The flow aloft is forecast to dry out and turn northwesterly by Saturday afternoon with low-level winds becoming north or northeasterly across the valley. A strong upper-level ridge is forecast to amplify over Eastern Oregon and Idaho Sunday, putting Western Oregon under weak southwesterly flow aloft. A thermal trough will build northward along the Oregon coast with strong offshore flow bringing significant drying and warming. Daytime highs will likely exceed 80 degrees across the Willamette Valley Sunday afternoon with 70-plus degrees warmth along the north coast. The strong upper-level ridge is forecast to slowly slide eastward Monday and Tuesday with increasing southerly flow aloft eventually increasing the high clouds over Western Oregon. Surface winds should remain offshore with a continuation of dry and unseasonably warm weather. There is a risk of late-day thundershowers moving into extreme Southern Oregon, due to the increasing unstable southerly flow aloft. As the ridge continues to shift eastward, it will open the door for a series of progressively wetter weather systems to come onshore beginning about Wednesday. Transport winds will likely turn too southerly for this transition to wet weather to provide a burning opportunity for remaining fields. The outlook is for wet conditions late next week, which will likely put a damper on futher burning for this season. Tomorrow (27 Sep): Mostly Sunny. 46/76 Sun (28 Sep): Sunny and Warm. 45/83 Mon (29 Sep): Increasing High Clouds and Warm. 49/85 Tue (30 Sep): Increasing High Clouds. 52/79 Wed (01 Oct): Mostly Cloudy. Increasing Chance of Rain. 52/69 Thu (02 Oct): Showers Early...Partial Clearing. 50/67 Fri (03 Oct): Rain...Possibly Heavy at Times. 50/63 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Sep 29 08:04:24 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 29 Sep 2008 10:04:24 -0500 Subject: [willamette-fcst] Forecast - Monday, September 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: Monday, September 29th, 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 ridge of high pressure built over the Pacific Northwest during the weekend with temperatures shooting well above normal. The ridge will slowly shift east today with increasing southeasterly flow aloft. That may bring a few clouds northward, over the Willamette Valley, this afternoon. Otherwise, it will be another sunny day today. The Salem sounding this morning showed further warming aloft, which will cap mixing heights near 2000 feet. Offshore flow will send valley temperatures into the mid to upper 80s this afternoon with low relative humidities. The morning ODA surface analysis showed a thermal trough just off the Oregon Coast with offshore flow across all of Oregon except for the south coast. Satellite imagery showed low clouds moving northward along the southern coast with clear skies over most of Oregon. Middle and high clouds were also rotating northward, across SW and South-Central Oregon, with Doppler radar even indicating some scattered light shower activity. The increasing southeasterly flow aloft may combine with daytime heating to trigger some thundershower development across Souther Oregon this afternoon. There is a chance that a thunderstorm or two could possibly move into the Central Cascades and/or the Southern Willamette Valley late this afternoon with at least some middle and high clouds making it this far north. Surface Winds: NNE 3-8 this morning, NNE 3-8 this afternoon. Transport Winds: NNE 6 this morning, N 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2000 feet. Ventilation index 16. High Temperature: Salem\'s high temperature today will be near 88. Humidities: Minimum relative humidity will be near 24%. Sunrise/Sunset: Salem sunset tonight: 6:55pm; sunrise tomorrow: 7:10am. Extended Outlook: As the upper-level ridge continues to shift east, south-southeasterly flow aloft will bring middle and high-level moisture farther north, across all of Oregon, Tuesday. Daytime heating may help trigger shower and thundershower development...mainly from the Cascades eastward. The combination of increase middle and high clouds and the thermal trough shifting inland will begin a cool-down west of the Cascades, although temperatures will remain well above normal. By Wednesday afternoon, the thermal trough is forecast to shift east of the Cascades with onshore flow beginning to usher much cooler air into the Willamette Valley. That transition may create a burning ofpportunity for remaining north-valley fields, if transport winds do not have too much of a southerly component. The first in a series of progressively wetter weather systems is forecast to come onshore Wednesday night or Thursday morning. A thick marine layer will likely by in place by Thursday morning with a little rain by afternoon. A more potent system is forecast to come onshore late Friday with increasing rain and wind by Friday afternoon. Rain will turn to showers Saurday with total rainfal amounts on the order of one inch forecast for the Willamette Valley by Saturday night. That could put a damper on futher burning for this season. Tomorrow (30 Sep): Increasing Middle & High Clouds. Slight Chance Shower. 52/82 Wed (01 Oct): Mostly Cloudy. Increasing Chance of Rain Late. 52/78 Thu (02 Oct): Cloudy and Much Cooler. Light Rain Likely at Times. 55/66 Fri (03 Oct): Rain...Possibly Heavy at Times. 50/63 Sat (04 Oct): Rain Turning to Showers. 51/63 Sun (05 Oct): Mostly Cloudy. Chance of Light Rain. 49/67 Mon (06 Oct): Mostly Cloudy. Chance of Rain. 50/68 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Sep 29 08:13:53 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 29 Sep 2008 10:13:53 -0500 Subject: [willamette-fcst] Forecast - Monday, September 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. ...Corrected Extended Forecast (Friday)... Issued: Monday, September 29th, 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 ridge of high pressure built over the Pacific Northwest during the weekend with temperatures shooting well above normal. The ridge will slowly shift east today with increasing southeasterly flow aloft. That may bring a few clouds northward, over the Willamette Valley, this afternoon. Otherwise, it will be another sunny day today. The Salem sounding this morning showed further warming aloft, which will cap mixing heights near 2000 feet. Offshore flow will send valley temperatures into the mid to upper 80s this afternoon with low relative humidities. The morning ODA surface analysis showed a thermal trough just off the Oregon Coast with offshore flow across all of Oregon except for the south coast. Satellite imagery showed low clouds moving northward along the southern coast with clear skies over most of Oregon. Middle and high clouds were also rotating northward, across SW and South-Central Oregon, with Doppler radar even indicating some scattered light shower activity. The increasing southeasterly flow aloft may combine with daytime heating to trigger some thundershower development across Souther Oregon this afternoon. There is a chance that a thunderstorm or two could possibly move into the Central Cascades and/or the Southern Willamette Valley late this afternoon with at least some middle and high clouds making it this far north. Surface Winds: NNE 3-8 this morning, NNE 3-8 this afternoon. Transport Winds: NNE 6 this morning, N 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2000 feet. Ventilation index 16. High Temperature: Salem\'s high temperature today will be near 88. Humidities: Minimum relative humidity will be near 24%. Sunrise/Sunset: Salem sunset tonight: 6:55pm; sunrise tomorrow: 7:10am. Extended Outlook: As the upper-level ridge continues to shift east, south-southeasterly flow aloft will bring middle and high-level moisture farther north, across all of Oregon, Tuesday. Daytime heating may help trigger shower and thundershower development...mainly from the Cascades eastward. The combination of increase middle and high clouds and the thermal trough shifting inland will begin a cool-down west of the Cascades, although temperatures will remain well above normal. By Wednesday afternoon, the thermal trough is forecast to shift east of the Cascades with onshore flow beginning to usher much cooler air into the Willamette Valley. That transition may create a burning ofpportunity for remaining north-valley fields, if transport winds do not have too much of a southerly component. The first in a series of progressively wetter weather systems is forecast to come onshore Wednesday night or Thursday morning. A thick marine layer will likely by in place by Thursday morning with a little rain by afternoon. A more potent system is forecast to come onshore late Friday with increasing rain and wind by Friday afternoon. Rain will turn to showers Saurday with total rainfal amounts on the order of one inch forecast for the Willamette Valley by Saturday night. That could put a damper on futher burning for this season. Tomorrow (30 Sep): Increasing Middle & High Clouds. Slight Chance Shower. 52/82 Wed (01 Oct): Mostly Cloudy. Increasing Chance of Rain Late. 52/78 Thu (02 Oct): Cloudy and Much Cooler. Light Rain Likely at Times. 54/66 Fri (03 Oct): Increasing Rain Late...Possibly Heavy at Times. 52/66 Sat (04 Oct): Rain Turning to Showers. 51/63 Sun (05 Oct): Mostly Cloudy. Chance of Light Rain. 49/67 Mon (06 Oct): Mostly Cloudy. Chance of Rain. 50/68 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Sep 29 11:04:35 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 29 Sep 2008 13:04:35 -0500 Subject: [willamette-fcst] Forecast - Monday, September 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: Monday, September 29th, 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 strong upper-level ridge over the region is slowly shifting east and was centered over Idaho late this morning. South-southeasterly flow aloft was circulating mid and high-level moisture into South-Central and Southwestern Oregon with Doppler radar indicating some light shower activity. Satellite imagery showed clouds making it northward, across Lane County, into Southern Linn County. Most of Eastern Oregon and all of Northern Oregon continued to have sunny skies as of late this morning. Valley temperatures were running about 10 degrees warmer than at the same time on Sunday and were mostly in the 70s. Some changes in the weather pattern were beginning to show up on the late-morning ODA surface analysis. The thermal trough had shifted inland, into Southwestern Oregon, and extended northwestward to off the Washington Coast. Onshore flow was advancing northward along the coast, with a blanket of low clouds extending as far north as Tillamook County. The north coast still had sunny skies, with offshore flow, but that will not last long. The thermal trough will likely shift inland, into the Willamette Valley, this afternoon, with low clouds moving northward along the entire length of the Oregon Coast. Some marine air may begin spilling into the Southern Willamette Valley by this evening, but prevailing winds in the valley should be light northerly this afternoon. Valley temperatures will approach record warm readings this afternoon, especially north, with high in the upper 80s. The increasing southeasterly flow aloft will continue to circulate middle and high clouds northward today across the Willamette Valley. That will block the sun and keep temperatures a few degrees cooler in the south valley today. Increasing mid-level instability may combine with daytime heating to trigger shower/thundershower development as far north as the Willamette Valley this afternoon and evening. The best chance of showers will be in the south valley. This is a classic summer-time thunderstorm pattern, for the Willamette Valley, but the sun angle is lower this time of the year, and that limits the amount of low-level energy available to fuel the storms. Surface Winds: N 3-8 this afternoon...possibly becoming NW 5-12 mph south valley late this afternoon. Transport Winds: N 8 this afternoon...possibly becoming NW 8 south valley late this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2300 feet. Ventilation index 18. High Temperature: Salem\'s high temperature today will be near 88. Humidities: Minimum relative humidity will be near 24%. Sunrise/Sunset: Salem sunset tonight: 6:55pm; sunrise tomorrow: 7:10am. Extended Outlook: As the upper-level ridge continues to shift east, south-southeasterly flow aloft will continue to spread middle and high-level moisture northward, across Oregon, Tuesday. Daytime heating may, once again, help trigger shower and thundershower development...mainly from the Cascades eastward. increased cloud-cover and the thermal trough shifting inland will begin a general cool-down, west of the Cascades, Tuesday. That may present a burning opportunity Tuesday afternoon, as mixing heights climg to near 3000 feet with forecast northwesterly transport winds. By Wednesday afternoon, the thermal trough is forecast to shift well east of the Cascades, with increasing onshore flow into the Willamette Valley. Transport winds are expected to increase from the south-southwest, presenting another possible burning opportunity. The first in a series of progressively wetter weather systems is forecast to come onshore Wednesday night with a good chance of light rain by Thursday morning...turning to showers in the afternoon. A more potent autumn cold front is forecast to come onshore late Friday with a soaking rain forecast for Friday night. Rain will turn to showers Saturday with total rainfal amounts possibly exceeding one inch in the valley. There is every reason to believe that will bring a damp end to the 2008 burning season. Tomorrow (30 Sep): Increasing Middle & High Clouds. Slight Chance Shower. 52/82 Wed (01 Oct): Mostly Cloudy. Increasing Chance of Rain Late. 52/78 Thu (02 Oct): Cloudy and Much Cooler. Light Rain Likely at Times. 55/66 Fri (03 Oct): Rain Increasing Late...Possibly Heavy at Times. 52/66 Sat (04 Oct): Rain Turning to Showers. 51/63 Sun (05 Oct): Mostly Cloudy. Chance of Light Rain. 49/67 Mon (06 Oct): Mostly Cloudy. Chance of Rain Late. 50/68 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Sep 30 08:05:24 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 30 Sep 2008 10:05:24 -0500 Subject: [willamette-fcst] Forecast - Tuesday, September 30th, 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, September 30th, 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 near-record high temperatures to Western Oregon Monday will very slowly move east today. The Salem sounding this morning showed some cooling aloft, associated with the eastward movement of the upper-level ridge. However, the air mass is still unseasonably warm, so mixing heights will not reach 3000 feet until later this afternoon, if at all. Satellite imagery showed a fairly wide band of mainly middle and high clouds extending from SW Oregon, through North-Central and NE Oregon. Doppler radar was showing scattered very light shower activity (most probably not reaching the ground) over the valley and the Central Cascades...moving northwest. Daytime heating will act to enhance the shower activity, but it is not expected to be heavy. Some sprikles have already been reported near Woodburn this morning. Slight cooling aloft and more clouds will knock several degrees off of the afternoon temperatures today with valley highs cooling in the low 80s. The ODA surface analysis showed the thermal trough extending from SW Oregon northward, through the Willamette Valley, with light winds across all of Western Oregon. If the thermal trough shifts east this afternoon and initiates a significant sea breeze, then some limited burning is possible. The unstable mid-level south to southeasterly flow makes that unlikely. The flow aloft is forecast to become more south-southwesterly overnight, which should stabilize the air mass over Western Oregon and decrease the threat of showers. Surface Winds: Var 0-5 this morning, NW 5 this afternoon. Transport Winds: SE 5 this morning, NNW 6 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 18. High Temperature: Salem\'s high temperature today will be near 83. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 32%. Sunrise/Sunset: Salem sunset tonight: 6:53pm; sunrise tomorrow: 7:11am. Extended Outlook: By Wednesday afternoon, increasing south-southwesterly flow aloft is forecast to force the surface thermal trough east of the Cascades. That may create a burning opportunity, if the flow aloft is not too southerly. The first in a series of progressively wetter weather systems is forecast to come onshore Wednesday night with a good chance of light rain, by midday Thursday, across the Willamette Valley. A more potent autumn-like cold front is forecast to come onshore late Friday with a soaking rain still forecast Friday night, along with blustery south winds. Rain will turn to showers Saturday with total rainfal amounts possibly exceeding one inch in the valley. A strong westerly jet stream is forecast over Washington and Northern Oregon Sunday, which will maintain onshore flow and at least a chance of rain. A transitory rideg of high pressure may bring some drying Monday, ahead of the next rain-maker on Tuesday. Tomorrow (01 Oct): Filtered Sunshine and Continued Warm. Increasing Clouds Late. 52/80 Thu (02 Oct): Cloudy and Much Cooler. Light Rain Likely by Afternoon. 55/66 Fri (03 Oct): Mostly Cloudy. Increasing Rain and Wind Late. 52/66 Sat (04 Oct): Rain Turning to Showers. 51/62 Sun (05 Oct): Mostly Cloudy. Chance of Light Rain. 49/64 Mon (06 Oct): Mostly Cloudy. Chance of Rain Late. 47/68 Tue (07 Oct): Rain Likely. 49/63 ODA Meteorologist weather at oda.state.or.us