From willamette-fcst at listsmart.osl.state.or.us Mon Aug 3 08:41:01 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 03 Aug 2009 10:41:01 -0500 Subject: [willamette-fcst] Forecast - Monday, August 3rd, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, August 3rd, 2009 at 8:40am. 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 nearly stationry upper-level low pressure center is spinning around about 400 miles off the central California coastline. It will continue to bring weak southerly flow aloft to the southern half of Oregon today, along with a chance of afternoon and evening thunderstorms. A drier and more stable weak westerly flow aloft prevails over Washington and extreme northern Oregon. The air mass aloft is still very warm with only weak onshore flow to moderate temperatures west of the Cascades. Some morning clouds did manage to make it into the southern Willamette Valley, but they should evaporate by midday. There are also some mid and high clouds over wesern Oregon, left over from the thunderstorm activity that developed over central Oregon Sunday afternoon. Willamette Valley temperatures were mostly in the low 60s, at mid-morning, with light southerly winds. Highs will range from the upper 80s in the south to the low 90s in the north...perhaps making this the tenth day in-a-row (a new record) of 90+ degree temperatures in the north valley. Weak onshore flow is slowly improving air quality and ventilation conditions across western Oregon, but mixing heights will only climb to about 3700 feet this afternoon. Warm air aloft, forecast light westerly transport winds, and thunderstorm development over central Oregon will act together to limit open burning opportinities this afternoon. Surface Winds: SW 0-5 this morning, W 5-10 this afternoon. Transport Winds: SW 4 this morning, W 6 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3700 feet. Ventilation index 22. 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 27%. Sunrise/Sunset: Salem sunset tonight: 8:35pm; sunrise tomorrow: 6:02am. Extended Outlook: The upper-level ridge axis is forecast to shift eastward, to over Idaho and northeastern Oregon, Tuesday afternoon, and to over western Montana Wednesday, as an upper-level low pressure center slowly approaches the northern California coastline. The flow aloft will remain southerly over most of Oregon with the potential for afternoon and evening thunderstorm development continuing...mainly over southern and eastern Oregon. By Wednesday evening, enough moisture may feed far enough north and west for a chance of thunderstorms even over the Willamette Valley. Weak onshore flow will slowly improve ventilation conditions and cool temperatures across western Oregon. The upper-level trough is forecast to move onshore Thursday, into northern California, bringing much stronger onshore flow and a significant cool-down across all of Oregon. There will also be a chance of showers across western Oregon, with the unstable air and threat of tunderstorms shifting well east of the Cascades. The trough is forecast to continue eastward, into Idaho and Nevada, Friday with a drier and stable westerly flow aloft spreading across Oregon. This major pattern transition will be closely monitored for potential open burning opportunities...especially during the second half of this week. A stronger weather system may bring some rain to the Willamette Valley by the end of the weekend. Tomorrow (04 Aug): Patchy AM Clouds. Partly Sunny. Risk T-Storm Near the Cascades. 60/88 Wed (05 Aug): Partly Cloudy to Mostly Cloudy. Chance of T-Storms. 57/85 Thu (06 Aug): Mostly Cloudy and Cooler. Chance of Showers. 56/77 Fri (07 Aug): AM Clouds. Parly Sunny. Slight Chance of a Shower. 53/76 Sat (08 Aug): AM Clouds. Parly Sunny. Slight Chance of a Shower. 52/76 Sun (09 Aug): Mostly Cloudy. Increasing Chance of Rain. 52/73 Mon (10 Aug): Mostly Cloudy. Chance of Showers. 53/76 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Aug 4 09:00:39 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 04 Aug 2009 11:00:39 -0500 Subject: [willamette-fcst] Forecast - Tuesday, August 4th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Tuesday, August 4th, 2009 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 pressure center was about 250 miles off the central California coastline and drifting slowly eastward this morning. It will continue to bring weak southerly flow aloft to the Oregon today, along with a chance of afternoon and evening thunderstorms...mainly south and from the Cascades eastward. A drier and more stable weak westerly flow aloft prevailed over Washington. The surface thermal trough extended from just east of The Dalles to near Redmond to near Medford, with continued weak onshore flow across the Willamette Valley. The air mass aloft is slowly cooling, but still very warm, with weak onshore flow slowly moderating temperatures west of the Cascades. Some morning clouds managed to make their way into the southern Willamette Valley again this morning, but they should evaporate by midday. There are also some mid and high clouds circulating over wesern Oregon, via the southerly flow aloft. Willamette Valley highs cooled into the upper 80s and low 90s Monday, and another 2-3 degrees of cooling is expected today. The record streak of 10 straight days of 90+ degree weather for Portland should come to an end today. The old record was set August 12-19, 1967. Salem had 9 straight days of 90 degrees or warmer until the 89-degree high yesterday. The Salem sounding this morning was very similar to yesterday morning, with continued very warm air aloft keeping mixing heights below 3000 feet until this aftenoon. Weak onshore flow is slowly improving air quality and ventilation conditions across western Oregon. Mixing heights should climb to around 4000 feet by late this afternoon. Forecast light westerly transport winds may create another limited open burning opportunity this afternoon, but thunderstorm development over central Oregon will need to be closely monitored. That could prevent smoke evacuation over the Cascades. As expected, the thunderstorms of the past few days have started a few widefires around the region. The largest fire in western Oregon is a 4500 acre blaze near highway 138 in the western Cascades of Douglas County. The wildfire potential will increase over the next couple of days, as the upper-level trough moves onshore and increases the thundershower activity...mainly from the Cascades eastward. Surface Winds: SW 0-8 this morning, WSW 5-10 this afternoon. Transport Winds: SW 4 this morning, W 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 28. High Temperature: Salem\'s high temperature today will be near 86. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 31%. Sunrise/Sunset: Salem sunset tonight: 8:34pm; sunrise tomorrow: 6:03am. Extended Outlook: The upper-level ridge axis is forecast to shift eastward, to over western Montana, on Wednesday, as an upper-level low-pressure center slowly approaches the northern California coastline. The flow aloft will remain southerly over Oregon with the potential for afternoon and evening thunderstorm development continuing...mainly from the Cascades eastward. By Wednesday evening, enough moisture may feed far enough north and west for a chance of showers and thunderstorms even over the Willamette Valley. Weak onshore flow will continue to slowly improve ventilation conditions and cool temperatures across western Oregon. The upper-level trough is forecast to move onshore Thursday, mainly across northern California, bringing much stronger onshore flow and a significant cool-down across all of Oregon. The threat of showers and thunderstorms will mainly shift easat of the Cascades, as a more stable westerly flow aloft invades western Oregon. The trough is forecast to continue eastward, into Idaho and Nevada, Friday with a drier northwesterly flow aloft spreading across Oregon. A stronger weather system may bring some rain to the Willamette Valley by the end of this weekend. Tomorrow (05 Aug): Partly Cloudy to Mostly Cloudy. Chance of Showers or T-Storms. 52/85 Thu (06 Aug): Mostly Cloudy and Cooler. Slight Chance of Showers. 52/77 Fri (07 Aug): AM Clouds. Parly Sunny. 52/77 Sat (08 Aug): AM Clouds. Parly Sunny. 52/80 Sun (09 Aug): Mostly Cloudy. Increasing Chance of Rain. 53/77 Mon (10 Aug): Mostly Cloudy. Chance of Showers. 53/76 Tue (11 Aug): Mostly Cloudy. Slight Chance of Showers. 53/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 5 08:23:22 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 05 Aug 2009 10:23:22 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 5th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 5th, 2009 at 8:20am. 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 center was about 200 miles off the northern California coastline and drifting slowly eastward this morning. It will continue the weak southerly flow aloft over Oregon today, along with a chance of afternoon and evening thunderstorms...mainly from the Cascades eastward. Marine low clouds penetrated across most of the Willamette Valley this morning but should give way to mostly sunny skies this afternoon. Mid-morning temperatures were in the comfortable 55-60 degree range across most of western Oregon. Willamette Valley highs only climbed to near-normal Tuesday and will be similar today (the normal high for Salem today is 83 degrees). The Salem sounding this morning showed a few degrees more cooling aloft, compared to Tuesday morning, so mixing heights should climb to just over 4000 feet by late this afternoon (compared to a maximum of about 3700 feet Tuesday afternoon). Forecast northwesterly transport winds should allow for limited open burning this afternoon, assuming the weak gradient-stacking from last night\'s marine influx is reversed by daytime heating. Once again, thunderstorm development over the Cascades, and across central Oregon, will need to be closely monitored. By this evening, enough moisture may feed far enough north and west to include a slight chance for a shower or thunderstorm over the Willamette Valley, but it appears that the bulk of the shower activity will stay east of the region. Surface Winds: W 0-6 this morning, NW 5-15 this afternoon. Transport Winds: SW 4 this morning, NW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4200 feet. Ventilation index 42. High Temperature: Salem\'s high temperature today will be near 82. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 33%. Sunrise/Sunset: Salem sunset tonight: 8:33pm; sunrise tomorrow: 6:04am. Extended Outlook: A weak weather system, cutting across southern British Columbia on Thursday, will finally force the upper-level trough off the California coast onshore. That will initiate a significant increase in onshore flow across western Oregon with much cooler temperatures. A burning opportunity is possible with this transition to a cooler air mass, because most of the moisture is forecast to stay south and east of the Willamette Valley. There will be considerable clouds and at least a slight chance of showers...especially over the southern Willamette Valley. The threat of showers and thunderstorms will increase, from the Cascades eastward, Thursday and Friday, with some storms possibly becoming quite strong. Due to the recent hot and dry weather, these storms have the potential to start many wildfires. The trough is forecast to continue eastward, into Idaho, Friday with a drier northwesterly flow aloft spreading from west to east across Oregon. A weak system is forecast to move across southern British Columbia over the weekend...maintining onshore flow, and below normal temperatures, across the interior of western Oregon. The long-range models differ on their timing and strength of a system coming onshore early next week. It should maintain below normal temperatures across western Oregon and could introduce a chance of rain...especially in the northern Willamette Valley. Tomorrow (06 Aug): Mostly Cloudy and Cooler. Slight Chance of Showers. 52/75 Fri (07 Aug): AM Clouds. Slight Chance of a Shower. Partial PM Clearing. 52/72 Sat (08 Aug): AM Clouds. Partly Sunny. 51/77 Sun (09 Aug): Partly Sunny and Continued Seasonably Cool. 52/77 Mon (10 Aug): Mostly Cloudy. Chance of Rain...Mainly North. 54/74 Tue (11 Aug): Mostly Cloudy. Chance of Showers...Mainly North. 54/78 Wed (12 Aug): Mostly Cloudy. Chance of Showers...Mainly North. 54/78 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Aug 6 08:53:43 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 06 Aug 2009 10:53:43 -0500 Subject: [willamette-fcst] Forecast - Thursday, August 6th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, August 6th, 2009 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 upper-level low pressure center, that has been off the California coastline for the past several days, is being forced onshore this morning by another system sliding across southern British Columbia. Increasing southerly flow aloft has spread cloudy skies and smoke, from California and southern Oregon wildfires, over most of Oregon this morning. Some sprinkles have fallen over the Willamette Valley, but, so far, the bulk of the moisture from this system has stayed south and east of the region. Partial clearing is expected this afternoon, especially in the north valley, as the upper-level trough continues eastward to over northwest Nevada. Some sprinkles or light showers are possible, but the main shower activity appears as if it will stay south and east of the Willamette Valley. The combination of cooling aloft, onshore flow, and mostly cloudy skies will drop Willamette Valley high temperatures about 10 degrees today (only climbing into the low 70s). Ventilation conditions will improve over western Oregon this afternoon. Mixing heights should climb to around 4000 feet with forecast westerly transport winds. Those are favorable conditons for open burning this afternoon. However, light showers are possible, which is not favorable for burning. In addition, the gradient-stacking is significant this morning and would need to be reversed, by daytime heating, for open burning to be possible this afternoon. Surface Winds: S 5-10 this morning, SW 5-10 this afternoon. Transport Winds: SW 5 this morning, W 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 72. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 47%. Sunrise/Sunset: Salem sunset tonight: 8:31pm; sunrise tomorrow: 6:05am. Extended Outlook: The upper-level trough is forecast to continue northeastward, into Idaho, Friday with a drier northwesterly flow aloft spreading from west to east across Oregon. Westerly transport winds are forecast Friday afternoon, but gradient-stacking, once again, may inhibit the chances for open burning. A weak system is forecast to move across southern British Columbia over the weekend...maintining onshore flow, and slightly below normal temperatures, across the interior of western Oregon. A stronger system is forecast to come onshore Monday with the potential to bring measurable rain to the Willamette Valley. Depending on the timing of this system, it may also create a burning opportunity. An even more potent system may come onshore as early as next Wednesday, but that is uncertain at this time. Tomorrow (07 Aug): AM Clouds. Slight Chance of a Shower. Partial PM Clearing. 52/72 Sat (08 Aug): AM Clouds. Partly Sunny. 51/77 Sun (09 Aug): AM Clouds. Mostly Sunny in the Afternoon. 52/80 Mon (10 Aug): Mostly Cloudy. Increasing Chance of Rain...Mainly North. 54/77 Tue (11 Aug): Mostly Cloudy. Chance of Showers...Mainly North. 53/75 Wed (12 Aug): Mostly Cloudy. Chance of Rain. 54/75 Thu (13 Aug): Mostly Cloudy. Chance of Showers. 54/75 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 7 08:45:23 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 07 Aug 2009 10:45:23 -0500 Subject: [willamette-fcst] Forecast - Friday, August 7th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 7th, 2009 at 8:45am. 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 2:00pm. Stack burning is not allowed. Weather Discussion: The upper-level low pressure center, that brought cloudy and much cooler weather to western Oregon Thursday, was centered over Idaho this morning. The counterclockwise circulation around it was still spinning clouds back over virtually all of Oregon this morning, with some showers continuing east of the Cascades. There is a deep marine layer over the Willamette Valley this morning...extending up to about 7500 feet, with a thick cloud-cover and areas of drizzle/sprinkles. Mostly just trace amounts of rain have been reported. Clouds will be persistent across western Oregon today, even as the parent upper-level trough pushes off to the east. There may be some partial clearing in the late afternoon. Cooler air aloft and cloudy skies will keep high temperatures near 70 degrees (more than 10 degrees below normal). With westerly transport winds today and the flow aloft turning from northeasterly to northwesterly, smoke from area wildfires is being evacuated from western Oregon. Willamette Valley and western Cascade nephelometer readings are falling back closer to normal levels this morning...an indication that the wildfire smoke is being pushed east of the region. Cooler air aloft should allow mixing heights to climb to near 3000 feet around noon, so limited prep burning was allowed. Due to the deep marine layer over western Oregon, there is about 4 millibars of gradient-stacking from Salem to Redmond this morning. With only partial clearing expected this afternoon, it is unlikely that west-side temperatures will warm enough to reverse that and allow for open burning. Surface Winds: SW 5-10 this morning, W 5-10 this afternoon. Transport Winds: W 6 this morning, W 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 71. Humidities: Minimum relative humidity will be near 50%. Sunrise/Sunset: Salem sunset tonight: 8:30pm; sunrise tomorrow: 6:06am. Extended Outlook: A very weak system is forecast to move across southern British Columbia over the weekend...maintaining onshore flow across western Oregon. Some drizzle is possible along the coast and in the northern Cascade foothills, but the bulk of western Oregon will stay dry with morning clouds giving way to afternoon clearing each day. Temperatures will remain below normal. The lastest computer guidance is backing off slightly on the strength of a seriers of weather systems slated to come onshore next week, which increases the chances that they will create burning opportunities, before bringing any rainfall to the Willamette Valley. The first system is forecast to move across southern British Columbia Monday with the chance for rain extending only about as far south as the Washington/Oregon border. The next system is forecast to move onshore late Tuesday and Wednesday. That system has a greater potential of bringing some light rain or showers to the Willamette Valley Tuesday night and Wednesday. A dry and weak westerly flow aloft is forecast by late next week. Tomorrow (08 Aug): AM Clouds. Partly Sunny in the Afternoon. 54/77 Sun (09 Aug): AM Clouds. Mostly Sunny in the Afternoon. 56/78 Mon (10 Aug): Mostly Cloudy North...Partly Cloudy South. 55/78 Tue (11 Aug): Increasing Clouds...Chance of Light Rain Late..Mainly North. 55/79 Wed (12 Aug): Mostly Cloudy. Chance of Rain. 55/74 Thu (13 Aug): Mostly Cloudy. Chance of Showers. 55/75 Fri (14 Aug): Am Clouds. Afternoon Clearing. Warmer. 53/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 10 08:54:18 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 10 Aug 2009 10:54:18 -0500 Subject: [willamette-fcst] Forecast - Monday, August 10th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, August 10th, 2009 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 impressive Pacific frontal system, for mid-August, was spreading rain into northwestern Washington this morning with high clouds extending as far south as northwestern Oregon. The front is forecast to very slowly sag southward today, with rain possibly spreading into extreme northwestern Oregon this afternoon. High and mid-level clouds will increase over the Willamette Valley...especially north. Temperatures will remain warm, with highs climbing into the upper 70s in the north valley and low 80s in the south valley. Ahead of the frontal system, surface gradients are weak southerly across western Oregon with even a slight offshroe component across northwestern Oregon. Low-level southerly flow, ahead of the frontal system, produced some warming aloft overnight, so it will take until about noon for mixing heights to climb to 3000 feet. Transport winds are south-southwesterly this morning and should slowly increase in speed and veer to southwesterly this afternoon. That should provide adequate ventilation for open burning, in the southern Willamette Valley. However, open burning in the north valley will depend on how much of a westerly component develops in the transport winds this afternoon. Surface heating and very slight cooling aloft should help mixing mixing heights climb to near 5000 feet by late this afternoon. Surface Winds: S 5-10 this morning, W 5-10 this afternoon. Transport Winds: SSW 10 this morning, SW 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5000 feet. Ventilation index 75. High Temperature: Salem\'s high temperature today will be near 81. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 37%. Sunrise/Sunset: Salem sunset tonight: 8:26pm; sunrise tomorrow: 6:10am. Extended Outlook: A weakending cold front will continue to sag aoutheastward, into extreme northwestern Oregon, Tuesday. Light rain could extend as far south as the northern Willamette Valley Tuesday afternoon, but forecast rain amounts are only a few hundredths of an inch, at most. The south valley will likely only see an increase in mid and high-level clouds Tuesday a a couple of degrees of cooling. It is possible that mixing heights and transport winds may be favorable for open burning Tuesday afternoon, especially in the south valley. The frontal boundary is forecast to continue to weaken and sag further south, over the Willamette Valley, Wednesday afternoon. That will bring lots of clouds to the region but little to no rainfall. If the front becomes weak enough, that pattern can produce a burning opportunity. On the other hand, if the front is a little stronger thatn forecast, it could also produce light rain...especially over the north valley. An upper-level trough is forecast to swing onshore Thursday and activate the surface cold front over western Oregon. That will likely cool temperatures and increase the chance for showers across the Willamette Valley...especially north. If conditions stay dry enough, that could also create a burning opportunity. A drier northwesterly flow aloft is forecast to move over western Oregon Friday through this weekend. Windflow at the surface and aloft is forecast to become northerly by Sunday, with more sunshine and slightly warmer temperatures. The flow is forecast to turn offshore by early next week...resulting in sunny skies and seasonal temperatures. Tomorrow (11 Aug): Mostly Cloudy North...Chance of Light Rain. Partly Cloudy South. 56/78 Wed (12 Aug): Mostly Cloudy. 56/78 Thu (13 Aug): Mostly Cloudy. Chance of Light Showers...Mainly North. 53/77 Fri (14 Aug): Morning Clouds...Partly Sunny in the Afternoon. 50/79 Sat (15 Aug): Morning Clouds. Partly Cloudy in the Afternoon. 52/80 Sun (16 Aug): Mostly Sunny. 53/83 Mon (17 Aug): Sunny. 54/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Aug 11 09:00:53 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 11 Aug 2009 11:00:53 -0500 Subject: [willamette-fcst] Forecast - Tuesday, August 11th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Tuesday, August 11th, 2009 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 impressive Pacific frontal system, for mid-August, was spreading rain across western Washington and extreme northwestern Oregon this morning. Clouds were increasing across the Willamette Valley...mainly north. Over three-quarters of an inch of rain have fallen, from Forks to Bellingham, in northwestern Washington. The Seattle area has picked up about one-quarter of an inch of rain in the past 24 hours, with one-tenth of an inch falling as far south as Olympia, Washington. Light rain extended as far south as Tillamook, along the coast, this morning, with just over one-tenth of an inch of rain falling in Astoria. Satellite imagery showed a band of clouds, associated with the active cold front, stretching from northeastern Washigton, across most of western Washington and the northern Oregon Coast, and then offshore. Radar showed areas of rain, along the cloud shield, extending into extreme northwestern Oregon. Light rain was being reported, at mid-morning, as far south and east as Hillsboro. The front is forecast to very slowly sag southward today, with rain likely spreading into at least western sections of the north valley this afternoon. Clouds will be on the increase across the remainder of the valley today. Temperatures climbed into the mid to upper 80s Monday but will cool into the upper 70s and low 80s today. The warmest readings will be in the south valley. The mid-morning ODA surface analysis showed weak onshore pressure gradients across western Oregon. Valley temperatures were in the low to mid 60s with light winds. Temperatures will need to warm into the mid 70s to lift mixing heights to near 3000 feet, which should in the early afternoon, with mixing heights possibly climing as high as 5000 feet by late this afternoon, especially in the south valley. Forecast southwesterly transport winds and high mixing heights should provide adequate ventilation for open burning, this afternoon, in the south valley. Ventilation conditions should also be favorable for open burning in the north valley this afternoon, so long as it stays dry. Surface Winds: S 0-6 this morning, W 5-10 this afternoon. Transport Winds: S 4 this morning, SW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5000 feet. Ventilation index 50. High Temperature: Salem\'s high temperature today will be near 80. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 41%. Sunrise/Sunset: Salem sunset tonight: 8:24pm; sunrise tomorrow: 6:11am. Extended Outlook: The frontal boundary is forecast to continue to weaken and sag further south, over the Willamette Valley, Wednesday afternoon. That will bring lots of clouds and a chance of light rain to the region, with the best chance of rain in the north valley. On one extreme, rainfall amounts could exceed one-quarter of an inch, but if the front becomes weak enough, it is also possible that sections of the valley, especially south, may not even get measurable rain. If the later occurs, then it is possible that the front could create yet another burning opportunity Wednesday afternoon...although that is looking less likely. An upper-level trough is forecast to follow the cold front onshore Thursday and could bring a few more showers to mainly the northern Willamette Valley. Stronger onshore flow will cool temperatures to well below mid-August normals. If conditions are dry enough, the passage of the upper-level trough could create a burning opportunity. A drier northwesterly flow aloft is forecast to move over western Oregon Friday and Saturday. Windflow at the surface and aloft is forecast to become northerly by Sunday, with more sunshine and warmer temperatures. The flow is forecast to turn offshore by early next week...resulting in sunny skies and a return to above normal temperatures. Tomorrow (12 Aug): Mostly Cloudy. Good Chance of Rain...Mainly North. 59/76 Thu (13 Aug): Mostly Cloudy. Chance of Light Showers...Mainly North. 56/74 Fri (14 Aug): Morning Clouds...Partly Sunny in the Afternoon. 50/79 Sat (15 Aug): Morning Clouds. Mostly Sunny in the Afternoon. 51/80 Sun (16 Aug): Mostly Sunny. 53/83 Mon (17 Aug): Sunny and Warm. 54/88 Tue (18 Aug): Sunny and Warm. 58/90 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 12 08:49:54 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 12 Aug 2009 10:49:54 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 12th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 12th, 2009 at 8:50am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 1:00pm until 6:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed, for dry stacks, from 1:00pm until 6:00pm. Weather Discussion: An impressive Pacific frontal system, for mid-August, spread rain across northwestern Oregon late Tuesday through the overnight period. Rainfall amounts varied greatly, from north to south, across the Willamette Valley. The Portland area locally picked up over three-quarters of an inch of rain, with only sprinkles falling over portions of Lane County. Rainfall in Marion and northern Linn Counties was generally around one-tenth of an inch, with lighter amounts in southern Linn County. The front was over extreme northwestern Oregon at mid-morning with light rain falling along the north coast and in the northern Willamette Valley, generally north of Marion County. Radar showed the main area of rain moving northeast of the Willamette Valley with very little activity movning onshore. Satellite imagery showed mostly cloudy skies covering the valley, with some thin spots in the clouds over much of the south valley. Cloudy skies kept temperatures generally in the muggy 60s overnight wit mid-morning readings in the mid to upper 60s. The front is forecast to slowly sag southward today, maintaining mostly cloudy skies over the Willamette Valley with a chance of light rain at times...mainly north. Continued onshore flow and cooler air aloft will combine to keep high temperatures from climbing much above the mid 70s (about 10 degrees below normal). Forecast southwesterly transport winds are favorable for burning, but fields are likely too damp for burning in the north valley. If the south valley stays dry, and there is enough afternoon warming to lift mixing heights above 3000 feet, then open burning there may be possible. Surface Winds: S 5-10 this morning, W 5-12 this afternoon. Transport Winds: S 12 this morning, SW 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 53. High Temperature: Salem\'s high temperature today will be near 75. Humidities: Minimum relative humidity will be near 56%. Sunrise/Sunset: Salem sunset tonight: 8:22pm; sunrise tomorrow: 6:12am. Extended Outlook: An upper-level trough is forecast to follow the cold front onshore Thursday and could bring a few more showers to mainly the northern Willamette Valley. Onshore flow and colder air aloft will keep temperatures well below mid-August normals. If fields are dry enough, and if surface winds do not become too strong, the passage of the upper-level trough could create a burning opportunity. A drier northwesterly flow aloft is forecast to move over western Oregon Friday and Saturday. The flow is forecast to become northerly by Sunday, and offshore early next week, with more sunshine and warmer temperatures. Near-record warm temperatures are possible by next Tuesday, with a very strong upper-level ridge forecast to build over the region. Tomorrow (13 Aug): Mostly Cloudy. Chance of Light Showers...Mainly North. 56/74 Fri (14 Aug): Morning Clouds...Clearing Skies in the Afternoon. 50/78 Sat (15 Aug): Mostly Sunny. 49/80 Sun (16 Aug): Sunny and Warmer. 51/85 Mon (17 Aug): Sunny and Very Warm. 54/90 Tue (18 Aug): Sunny and Very Warm. 58/95 Wed (19 Aug): Mostly Sunny and Warm. 58/91 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Aug 13 08:50:20 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 13 Aug 2009 10:50:20 -0500 Subject: [willamette-fcst] Forecast - Thursday, August 13th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, August 13th, 2009 at 8:50am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is allowed from 11:00am until 5:00pm. Stack burning is not allowed. Weather Discussion: The Pacific frontal system, that brought significant rain to much of the northern Willamette Valley Tuesday night, pushed southeastward across Oregon Wednesday afternoon. It brought a few more showers to mainly the extreme southern Willamette Valley last night. Blustery west winds aided in the drying of damp fields Wednesday afternoon. Some sunshine helped valley high temperatures climb int the upper 70s. The cold front had pushed south and east of Oregon by this morning, with only residual low clouds over the Willamette Valley. Mid-morning valley temperatures were mostly in the upper 50s with northwest winds around 5 mph. The low clouds should give way to some sunshine later this morning, through early this afternoon, but temperatures will only climb into the mid 70s due to very cool air aloft. That should be enough warming to overcome about 3 millibars of gradient-stacking, from Salem to Redmond, this morning, but that will need to be monitored this afternoon. An upper-level trough is forecast to drop southeastward, along the southern British Columbia and Washington coastlines, this afternoon...resulting in west-northwesterly transport winds and very high mixing heights over western Oregon. That should create favorable conditions, early this afternoon, for open burning, if relative humidities can drop below 50%. There are other potential limiting factors to open burning this afternoon...First of all, damp fields will need to be fluffed, before they can be burned. In addition, the upper-level trough is quite vigorous and may get close enough to bring showers into the north valley by mid to late afternoon. The southward progression of shower activity will need to be closely monitored this afternoon. Surface winds may also become too strong for safe ignition and/or good plume rise by late this afternoon and will also be closely watched. The upper-level trough is forecast to move onshore this evening with a good chance of showers over the north valley and a slight chance of showers in the south valley. Rainfall amounts from this system are forecast to be spotty and much less than with the leading cold front that came through earlier this week. The south valley may stay dry, with north-valley totals likely less than one-tenth of an inch. Surface Winds: NW 5-10 this morning, W 5-15 this afternoon. Transport Winds: NNW 7 this morning, WNW 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 6000 feet. Ventilation index 72. High Temperature: Salem\'s high temperature today will be near 74. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 40%. Sunrise/Sunset: Salem sunset tonight: 8:21pm; sunrise tomorrow: 6:13am. Extended Outlook: As the upper-level trough pushes east, to over eastern Oregon Friday afternoon, a drier northwesterly flow aloft is forecast to move over western Oregon. That may also create a burning opportunity, if surface winds are not too strong, and there is not too much gradient-stacking. The flow aloft is forecast to become northerly Saturday and Sunday, and offshore early next week, as a strong upper-level ridge builds along the west coast. Temperatures will rapidly warm across western Oregon Sunday through Tuesday. With a surface thermal trough building into western Oregon, low-level winds will turn offshore, except along the immediate coastline. The long-range computer models differ on how and when the ridge will eventually break down, but it appears as if some cooling will begin by next Wednesday. That may create a burning opportunity, as the windflow turns back onshore. Tomorrow (14 Aug): Mostly Cloudy AM. Chance Shower...Mainly North. PM Clearing. 50/76 Sat (15 Aug): Mostly Sunny. 49/80 Sun (16 Aug): Sunny and Warmer. 51/85 Mon (17 Aug): Sunny and Very Warm. 54/90 Tue (18 Aug): Sunny and Very Warm. 58/95 Wed (19 Aug): Mostly Sunny and Warm. Slight Chance of PM T-Storms. 58/91 Thu (20 Aug): Mostly Sunny and Warm. Slight Chance of T-Storms. 55/88 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 14 08:50:38 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 14 Aug 2009 10:50:38 -0500 Subject: [willamette-fcst] Forecast - Friday, August 14th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 14th, 2009 at 8:50am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is allowed from 11:00am until 2:00pm with a 100 acre limit. Propane flaming is allowed from 11:00am until 2:00pm. Stack burning is not allowed. Weather Discussion: An unseasonably cool upper-level trough is over the Pacific Northwest this morning. The upper-level trough axis moved across western Oregon Thursday evening but did not produce much in the way of shower activity. Most of the moisture from this system is well north and east of western Oregon, but the air aloft is quite cool for mid-August. The freezing level over Salem was measured at just 7500 feet, compared with a mid-August average of 12,400 feet. The cool and unstable atmosphere helped to keep skies at least partially clear overnight, across western Oregon, with early morning temperatures locally dropping into the mid to upper 40s. Eugene and Corvallis both dipped down to 47 degrees. Mid-morning readings were mostly in the low to mid 50s with numerous sunbreaks and light winds. Skies should be partly to mostly sunny this afternoon, with a drier northwesterly flow aloft. Willamette Valley highs will only climb into the low 70s, with increasing northwesterly winds this afternoon. The air mass is cool and moist enough for convective cloud development, once surface temperatures reach about 62 degrees, which should occur late this morning. I do not expect the convection to be strong enough to develop showers, but the development of \\\"fair weather\\\" cumulus clouds will be a good indicator of mixing height (they shoud form between 2500 and 3000 feet late this morning). Cold air aloft will likely combine with daytime heating to lift mixing heights to over 5000 feet this afternoon. High mixing heights, combined with northwesterly transport winds, should provide adequate ventilation to allow for open burning in the north valley this afternoon. Winds may be too northerly to allow for burning in the south valley today. Winds are expected to turn more northerly overnight. Surface Winds: NW 5-10 this morning, NW 5-15 this afternoon. Transport Winds: NW 5 this morning, NW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5500 feet. Ventilation index 55. High Temperature: Salem\'s high temperature today will be near 72. Humidities: Relative humidity drops to 50% around 2pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 8:19pm; sunrise tomorrow: 6:14am. Extended Outlook: The flow aloft is forecast to become northerly Saturday and Sunday, as a strong upper-level ridge builds along the west coast. Temperatures will rapidly warm across western Oregon through Tuesday, as a surface thermal trough builds northward, into western Oregon. Low-level winds will turn offshore early next week, even along the northern and central coast. It appears as if a slow cooling trend will begin around the middle of next week, as the upper-level ridge, and associated surface thermal trough, both shift east of the Cascades. That may create a burning opportunity, as soon as Wednesday afternoon, with the low-level winds turning back onshore. Tomorrow (15 Aug): Mostly Sunny. 48/78 Sun (16 Aug): Sunny and Warmer. 50/84 Mon (17 Aug): Sunny and Very Warm. 52/88 Tue (18 Aug): Sunny and Very Warm. 54/92 Wed (19 Aug): Mostly Sunny and Warm. Possible Onshore Flow Late. 56/89 Thu (20 Aug): Mostly Sunny and a Little Cooler. Onshore Flow in the Afternoon. 55/86 Fri (21 Aug): Patchy AM Clouds. Afternoon Sunshine. 55/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 14 09:45:11 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 14 Aug 2009 11:45:11 -0500 Subject: [willamette-fcst] Forecast - Friday, August 14th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 14th, 2009 at 8:50am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is allowed from 11:00am until 2:00pm with a 100 acre limit. Propane flaming is allowed from 11:00am until 2:00pm. Stack burning is not allowed. Weather Discussion: An unseasonably cool upper-level trough is over the Pacific Northwest this morning. The upper-level trough axis moved across western Oregon Thursday evening but did not produce much in the way of shower activity. Most of the moisture from this system is well north and east of western Oregon, but the air aloft is quite cool for mid-August. The freezing level over Salem was measured at just 7500 feet, compared with a mid-August average of 12,400 feet. The cool and unstable atmosphere helped to keep skies at least partially clear overnight, across western Oregon, with early morning temperatures locally dropping into the mid to upper 40s. Eugene and Corvallis both dipped down to 47 degrees. Mid-morning readings were mostly in the low to mid 50s with numerous sunbreaks and light winds. Skies should be partly to mostly sunny this afternoon, with a drier northwesterly flow aloft. Willamette Valley highs will only climb into the low 70s, with increasing northwesterly winds this afternoon. The air mass is cool and moist enough for convective cloud development, once surface temperatures reach about 62 degrees, which should occur late this morning. I do not expect the convection to be strong enough to develop showers, but the development of \\\"fair weather\\\" cumulus clouds will be a good indicator of mixing height (they shoud form between 2500 and 3000 feet late this morning). Cold air aloft will likely combine with daytime heating to lift mixing heights to over 5000 feet this afternoon. High mixing heights, combined with northwesterly transport winds, should provide adequate ventilation to allow for open burning in the north valley this afternoon. Winds may be too northerly to allow for burning in the south valley today. Winds are expected to turn more northerly overnight. Surface Winds: NW 5-10 this morning, NW 5-15 this afternoon. Transport Winds: NW 5 this morning, NW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5500 feet. Ventilation index 55. High Temperature: Salem\'s high temperature today will be near 72. Humidities: Relative humidity drops to 50% around 2pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 8:19pm; sunrise tomorrow: 6:14am. Extended Outlook: The flow aloft is forecast to become northerly Saturday and Sunday, as a strong upper-level ridge builds along the west coast. Temperatures will rapidly warm across western Oregon through Tuesday, as a surface thermal trough builds northward, into western Oregon. Low-level winds will turn offshore early next week, even along the northern and central coast. It appears as if a slow cooling trend will begin around the middle of next week, as the upper-level ridge, and associated surface thermal trough, both shift east of the Cascades. That may create a burning opportunity, as soon as Wednesday afternoon, with the low-level winds turning back onshore. Tomorrow (15 Aug): Mostly Sunny. 48/78 Sun (16 Aug): Sunny and Warmer. 50/84 Mon (17 Aug): Sunny and Very Warm. 52/88 Tue (18 Aug): Sunny and Very Warm. 54/92 Wed (19 Aug): Mostly Sunny and Warm. Possible Onshore Flow Late. 56/89 Thu (20 Aug): Mostly Sunny and a Little Cooler. Onshore Flow in the Afternoon. 55/86 Fri (21 Aug): Patchy AM Clouds. Afternoon Sunshine. 55/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 14 09:47:42 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 14 Aug 2009 09:47:42 -0700 Subject: [willamette-fcst] Willamette Valley Ag/Burning Forecast/Backup Mailing Method Message-ID: Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 14th, 2009 at 8:50am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is allowed from 11:00am until 2:00pm with a 100 acre limit. Propane flaming is allowed from 11:00am until 2:00pm. Stack burning is not allowed. Weather Discussion: An unseasonably cool upper-level trough is over the Pacific Northwest this morning. The upper-level trough axis moved across western Oregon Thursday evening but did not produce much in the way of shower activity. Most of the moisture from this system is well north and east of western Oregon, but the air aloft is quite cool for mid-August. The freezing level over Salem was measured at just 7500 feet, compared with a mid-August average of 12,400 feet. The cool and unstable atmosphere helped to keep skies at least partially clear overnight, across western Oregon, with early morning temperatures locally dropping into the mid to upper 40s. Eugene and Corvallis both dipped down to 47 degrees. Mid-morning readings were mostly in the low to mid 50s with numerous sunbreaks and light winds. Skies should be partly to mostly sunny this afternoon, with a drier northwesterly flow aloft. Willamette Valley highs will only climb into the low 70s, with increasing northwesterly winds this afternoon. The air mass is cool and moist enough for convective cloud development, once surface temperatures reach about 62 degrees, which should occur late this morning. I do not expect the convection to be strong enough to develop showers, but the development of \"fair weather\" cumulus clouds will be a good indicator of mixing height (they shoud form between 2500 and 3000 feet late this morning). Cold air aloft will likely combine with daytime heating to lift mixing heights to over 5000 feet this afternoon. High mixing heights, combined with northwesterly transport winds, should provide adequate ventilation to allow for open burning in the north valley this afternoon. Winds may be too northerly to allow for burning in the south valley today. Winds are expected to turn more northerly overnight. Surface Winds: NW 5-10 this morning, NW 5-15 this afternoon. Transport Winds: NW 5 this morning, NW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5500 feet. Ventilation index 55. High Temperature: Salem's high temperature today will be near 72. Humidities: Relative humidity drops to 50% around 2pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 8:19pm; sunrise tomorrow: 6:14am. Extended Outlook: The flow aloft is forecast to become northerly Saturday and Sunday, as a strong upper-level ridge builds along the west coast. Temperatures will rapidly warm across western Oregon through Tuesday, as a surface thermal trough builds northward, into western Oregon. Low-level winds will turn offshore early next week, even along the northern and central coast. It appears as if a slow cooling trend will begin around the middle of next week, as the upper-level ridge, and associated surface thermal trough, both shift east of the Cascades. That may create a burning opportunity, as soon as Wednesday afternoon, with the low-level winds turning back onshore. Tomorrow (15 Aug): Mostly Sunny. 48/78 Sun (16 Aug): Sunny and Warmer. 50/84 Mon (17 Aug): Sunny and Very Warm. 52/88 Tue (18 Aug): Sunny and Very Warm. 54/92 Wed (19 Aug): Mostly Sunny and Warm. Possible Onshore Flow Late. 56/89 Thu (20 Aug): Mostly Sunny and a Little Cooler. Onshore Flow in the Afternoon. 55/86 Fri (21 Aug): Patchy AM Clouds. Afternoon Sunshine. 55/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 14 10:09:25 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 14 Aug 2009 12:09:25 -0500 Subject: [willamette-fcst] Forecast - Friday, August 14th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 14th, 2009 at 8:50am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is allowed from 11:00am until 2:00pm with a 100 acre limit. Propane flaming is allowed from 11:00am until 2:00pm. Stack burning is not allowed. Weather Discussion: An unseasonably cool upper-level trough is over the Pacific Northwest this morning. The upper-level trough axis moved across western Oregon Thursday evening but did not produce much in the way of shower activity. Most of the moisture from this system is well north and east of western Oregon, but the air aloft is quite cool for mid-August. The freezing level over Salem was measured at just 7500 feet, compared with a mid-August average of 12,400 feet. The cool and unstable atmosphere helped to keep skies at least partially clear overnight, across western Oregon, with early morning temperatures locally dropping into the mid to upper 40s. Eugene and Corvallis both dipped down to 47 degrees. Mid-morning readings were mostly in the low to mid 50s with numerous sunbreaks and light winds. Skies should be partly to mostly sunny this afternoon, with a drier northwesterly flow aloft. Willamette Valley highs will only climb into the low 70s, with increasing northwesterly winds this afternoon. The air mass is cool and moist enough for convective cloud development, once surface temperatures reach about 62 degrees, which should occur late this morning. I do not expect the convection to be strong enough to develop showers, but the development of \\\"fair weather\\\" cumulus clouds will be a good indicator of mixing height (they shoud form between 2500 and 3000 feet late this morning). Cold air aloft will likely combine with daytime heating to lift mixing heights to over 5000 feet this afternoon. High mixing heights, combined with northwesterly transport winds, should provide adequate ventilation to allow for open burning in the north valley this afternoon. Winds may be too northerly to allow for burning in the south valley today. Winds are expected to turn more northerly overnight. Surface Winds: NW 5-10 this morning, NW 5-15 this afternoon. Transport Winds: NW 5 this morning, NW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5500 feet. Ventilation index 55. High Temperature: Salem\'s high temperature today will be near 72. Humidities: Relative humidity drops to 50% around 2pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 8:19pm; sunrise tomorrow: 6:14am. Extended Outlook: The flow aloft is forecast to become northerly Saturday and Sunday, as a strong upper-level ridge builds along the west coast. Temperatures will rapidly warm across western Oregon through Tuesday, as a surface thermal trough builds northward, into western Oregon. Low-level winds will turn offshore early next week, even along the northern and central coast. It appears as if a slow cooling trend will begin around the middle of next week, as the upper-level ridge, and associated surface thermal trough, both shift east of the Cascades. That may create a burning opportunity, as soon as Wednesday afternoon, with the low-level winds turning back onshore. Tomorrow (15 Aug): Mostly Sunny. 48/78 Sun (16 Aug): Sunny and Warmer. 50/84 Mon (17 Aug): Sunny and Very Warm. 52/88 Tue (18 Aug): Sunny and Very Warm. 54/92 Wed (19 Aug): Mostly Sunny and Warm. Possible Onshore Flow Late. 56/89 Thu (20 Aug): Mostly Sunny and a Little Cooler. Onshore Flow in the Afternoon. 55/86 Fri (21 Aug): Patchy AM Clouds. Afternoon Sunshine. 55/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 14 11:54:35 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 14 Aug 2009 13:54:35 -0500 Subject: [willamette-fcst] Forecast - Friday, August 14th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. NOON UPDATE Issued: Friday, August 14th, 2009 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is allowed from now until 2:00pm with a 100 acre limit. Propane flaming is allowed from now until 2:00pm. Stack burning is not allowed. Weather Discussion: An unseasonably cool upper-level trough is over the Pacific Northwest this morning. The main upper-level trough axis moved across western Oregon Thursday evening and was pusing across Idaho late this morning. On the back side of the parent trough, a smaller spoke of upper-level energy was visible on satellite imagery, late this morning, rotating southeastwawrd onto the Washington and extreme northern Oregon Coast late this morning. That weak disturbance is forcast to rotate over the Willamette Valley this afternoon...maintaining the cool pool of air aloft and weak convective cloud development. It is unlikely that the convection will be strong enough to produce showers over the Willamette Valley, but an isolated shower is possible over the coastal range and western slopes of the Cascades. Once surface temperatures climbed into the low 60s, late this morning, convective clouds began developing, between 3000 and 3500 feet over northwestern Oregon, due to very cold air and cyclonic flow aloft. As a result, skies had become mostly cloudy over the valley. Late-morning temperatures had only warmed into the mid 60s with light and variable surface winds. Mixing down of colder air aloft will slow the rate of warming for the remainder of the day, with high temperatures only climbing into the low 70s. Daytime heating should drop relative humidities to near 50 percent, and raise mixing heights to near 5000 feet, by about 2pm. Transport winds are forecast to be about 330 degrees this afternoon, which should allow for open burning in the north valley. Some limited burning may be possible in the south valley. Pibals will begin at 1pm. Surface Winds: NW 5-15 this afternoon. Transport Winds: NW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5500 feet. Ventilation index 55. High Temperature: Salem\'s high temperature today will be near 72. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 8:19pm; sunrise tomorrow: 6:14am. Extended Outlook: The flow aloft is forecast to become northerly Saturday and Sunday, as a strong upper-level ridge builds along the west coast. Temperatures will rapidly warm across western Oregon through Tuesday, as a surface thermal trough builds northward, into western Oregon. Low-level winds will turn offshore early next week, even along the northern and central coast. That may allow for the burning of fields on extreme west side of the valley. It appears as if a slow cooling trend will begin around the middle of next week, as the upper-level ridge, and associated surface thermal trough, both shift east of the Cascades. That may create afternoon burning opportunities, beginning as soon as Wednesday, with the low-level winds turning back onshore. Tomorrow (15 Aug): Mostly Sunny. 48/78 Sun (16 Aug): Sunny and Warmer. 49/84 Mon (17 Aug): Sunny and Very Warm. 52/88 Tue (18 Aug): Sunny and Very Warm. 54/92 Wed (19 Aug): Mostly Sunny and Warm. Possible Onshore Flow Late. 56/89 Thu (20 Aug): Mostly Sunny and a Little Cooler. Onshore Flow in the Afternoon. 55/86 Fri (21 Aug): Patchy AM Clouds. Afternoon Sunshine. 55/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 17 08:41:29 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 17 Aug 2009 10:41:29 -0500 Subject: [willamette-fcst] Forecast - Monday, August 17th, 2009 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. ...State Fire Marshal Conditions will likely be met in sections of the valley later this afternoon, due to low humidities and increasing northerly winds...mainly south... Issued: Monday, August 17th, 2009 at 8:40am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 11:00am until 7:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A building ridge of high pressure, just offshore, will bring a dry and warmer north-northeasterly flow aloft to western Oregon today. Mid-morning satellite imagery showed only bands of high clouds streaming southward across Washington and much of Oregon. There were some low clouds along sections of the immediate coastline. Those should move offshore later this morning with sunshine statewide by this afternoon. The Salem sounding showed considerable warming aloft this morning, so temperatures will be about 10 degrees warmer across the Willamette Valley this afternoon. Highs should warm into the upper 80s, as a surface thermal trough continues to build northward along the Oregon Coast. Offshore flow will drop relative humidities below 30% across the valley later this afternoon. In addition, increasing northerly winds will likely put much of the south valley, and possibly areas of the north valley, into State Fire Marshal Conditions by late this aftenroon. However, northeasterly transport winds may allow for the burning of fields on the extreme western side of the south valley late this morning. Other open burning is highly unlikely today. Surface Winds: NNE 5-15 this morning, N 10-20 G25 south this afternoon. Transport Winds: NE 17 this morning, NNE 22 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 77. High Temperature: Salem\'s high temperature today will be near 88. Humidities: Relative humidity drops to 50% by 11am. Minimum relative humidity will be near 28%. Sunrise/Sunset: Salem sunset tonight: 8:15pm; sunrise tomorrow: 6:18am. Extended Outlook: The strong upper-level ridge of high pressure is forecast to slide eastward, to directly over Washington and Oregon, by Wednesday. Low-level winds will stay offshore Tuesday, with the surface thermal trough moving over the Willamette Valley Wednesday. Temperatures will continue to warm, across the Willamette Valley, Tuesday and Wednesday, with some daily high temperature records in jeopardy. The upper-level ridge is forecast to move east of the Cascades Tuesday, with southerly or southwesterly flow aloft over western Oregon. Some onshore flow, at the surface, will likely cool temperatures a few degrees across the interior valleys of western Oregon. That may create a burning opportunity. However, if the flow aloft becomes southerly, rather than southwesterly, that would decrease the chances for a burning opportunity and add a risk of thunderstorms...especially over the Cascades. The upper-level flow is forecast to become southwesterly by Friday, with increasing onshore flow at the surface continuing the cooling trend across western Oregon. That is also a potential burning opportunity but too far out to be certain of at this time. A weak trough is forecast to bring more cooling to western Oregon Saturday, but little to no rainfall. A weak ridge may bring some minor warming to the region Sunday and Monday. Tomorrow (18 Aug): Sunny. 56/94 Wed (19 Aug): Sunny. 58/97 Thu (20 Aug): Mostly Sunny. Slight Chance of PM T-Storms near the Cascades. 60/90 Fri (21 Aug): Mostly Sunny but Cooler. 58/85 Sat (22 Aug): Partly Cloudy and Cooler. 54/79 Sun (23 Aug): Am Clouds. PM Sunshine. 53/81 Mon (24 Aug): Mostly Sunny. 53/85 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Aug 18 08:48:38 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 18 Aug 2009 10:48:38 -0500 Subject: [willamette-fcst] Forecast - Tuesday, August 18th, 2009 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. ...State Fire Marshal Conditions will likely be met by mid-afternoon... Issued: Tuesday, August 18th, 2009 at 8:45am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A strong ridge of high pressure was centered just offshore this morning. The air mass aloft is very warm and will allow for the intense August sun to warm valley temperatures to near-record highs this afternoon. The mid-morning ODA surface analysis showed a strong thermal trough extending from the northern California/southern Oregon coast northeastward, through the Willamette Valley, into south-central Washington. Northeasterly transport winds may allow for open burning of fields on the extreme western side of the south valley, late this morning, if low-level winds are not too strong, by the time mixing heights climb above 2000 feet. Other open burning is highly unlikely today. After peaking in the upper 80s and lower 90s Monday afternoon, valley minimums only dipped into the the uper 50s and low 60s this morning. The Salem sounding showed further warming this morning, so highs should climb into the mid to upper 90s today...possibly setting some new daily records. Like yesterday, the combination of high temperatures, increasing northerly winds, and low humidities will likely put much of the valley into State Fire Marshal Conditions by mid-afternoon. Visible satellite imagery showed only a shallow layer of low clouds along the immediate coastline, which should evaporate by this afternoon, with increasing northerly winds. Even some of the beaches may locally warm to 80 degrees today, with much warmer temperatures just inland. Only a few high clouds were spreading over the remainder of Oregon this morning, in a weakening northerly flow aloft. A full day of sunshine will warm temperatures east of the Cascades into the 80s and 90s. Surface Winds: NNE 5-15 this morning, NNE 8-15 G25 south this afternoon. Transport Winds: NNE 12 this morning, NNE 17 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 51. High Temperature: Salem\'s high temperature today will be near 98. Humidities: Minimum relative humidity will be near 20%. Sunrise/Sunset: Salem sunset tonight: 8:13pm; sunrise tomorrow: 6:19am. Extended Outlook: The strong upper-level ridge of high pressure is forecast to slide eastward, to over Washington and Oregon on Wednesday. The surface thermal trough will remain over the Willamette Valley, with light winds and triple-digit highs likely. Many daily high temperature records are in jeopardy. High temperatures and low humidities will likely put most of the valley into State Fire Marshal Conditions again Wednesday afternoon. The upper-level ridge is forecast to move over Idaho Thursday, with increasing southwesterly flow aloft over western Oregon. Some onshore flow, at the surface, will likely develop Thursday afternoon...cooling temperatures about 10 degrees and possibly creating a burning opportunity. Increasing southwesterly flow aloft, and onshore flow at the surface, will continue the cooling trend across western Oregon on Friday. There could also be a burning opportunity Friday afternoon, if too much marine air hasn\'t already invaded the valley by that time. A weak trough is forecast to bring a deeper layer of marine air into the Willamette Valley by Saturday but little to no rainfall. Onshore flow is forecast to continue Sunday through Tuesday with little to no rainfall and seasonal temperatures. Tomorrow (19 Aug): Sunny and Hot. 64/101 Thu (20 Aug): Mostly Sunny and not as Hot. 64/90 Fri (21 Aug): Mostly Sunny and Cooler. 56/85 Sat (22 Aug): AM Clouds. PM Sunshine. 53/81 Sun (23 Aug): AM Clouds. PM Sunshine. 54/84 Mon (24 Aug): Partly Cloudy. 54/86 Tue (25 Aug): Partly Cloudy. 54/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 19 09:01:15 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 19 Aug 2009 11:01:15 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 19th, 2009 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. ...State Fire Marshal Conditions are likely later this afternoon... Issued: Wednesday, August 19th, 2009 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A strong ridge of high pressure will move directly over Washington and Oregon today, with Willamette Valley highs near 100 degrees. Northeasterly transport winds may allow for open burning of fields, on the extreme western side of the south valley, late this morning. Other open burning is highly unlikely today. The Salem sounding showed further warming aloft this morning, so valley highs should climb to around 100 degrees this afternoon, after hitting the mid 90s Tuesday (most locations were only a degree or two shy of daily record highs). Astoria tied their record high Tuesday with 82 degrees. The mid-morning ODA surface analysis showed the thermal trough covering all of western Oregon and extending into south-central Washington. Visible satellite imagery showed considerable low clouds just off the length of the Washington and Oregon coastline this morning...an indication of increasing westerly low-level flow approaching the coast. Skies remained mostly clear over Oregon. Mid-morning temperatures were in the 50s along the coast but had already warmed into the low 70s in portions of the Willamette Valley (a few degrees warmer than 24 hours ago in some locations). Onshore flow will cool the immediate coastline into the 60s and low 70s today, while the interior valleys of western Oregon continue to heat up. Many daily records are in jeopardy, including the record high of 98 degrees for Salem (previously set in 1939) and 94 for Portland (previously set in 1967). The record high of 100 for Eugene (also set in 1939) may stand. It will be close, because temperatures aloft support surface temperatures reaching the century mark this afternoon. Like yesterday, the combination of high temperatures and low humidities will likely put much of the valley into State Fire Marshal Conditions during the mid-to-late afternoon period. Surface Winds: Var 0-6 this morning, NW 5-10 this afternoon. Transport Winds: NE 8 this morning, SE 4 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3200 feet. Ventilation index 26. High Temperature: Salem\'s high temperature today will be near 100. Humidities: Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 8:11pm; sunrise tomorrow: 6:20am. Extended Outlook: The upper-level ridge is forecast to move over Idaho Thursday, with increasing southwesterly flow aloft over western Oregon. Onshore flow will likely develop Thursday afternoon...cooling temperatures about 10 degrees and likely creating a burning opportunity. A fairly strong marine push is forecast for Thursday night with low clouds likely forming over the western valleys by Friday morning. Increasing southwesterly flow aloft, and onshore flow at the surface, will continue the cooling trend across western Oregon on Friday. A weak trough is forecast to bring a deeper layer of marine air into the Willamette Valley by Saturday. Onshore flow is forecast to continue Sunday through Tuesday with little to no rainfall and seasonal temperatures. Tomorrow (20 Aug): Mostly Sunny and not as Hot. 64/90 Fri (21 Aug): Mostly Sunny and Cooler. 56/85 Sat (22 Aug): AM Clouds. PM Sunshine. 53/81 Sun (23 Aug): AM Clouds. PM Sunshine. 54/84 Mon (24 Aug): Partly Cloudy. 54/86 Tue (25 Aug): Partly Cloudy. 54/82 Wed (26 Aug): Partly Cloudy. 54/81 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Aug 20 09:01:39 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 20 Aug 2009 11:01:39 -0500 Subject: [willamette-fcst] Forecast - Thursday, August 20th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, August 20th, 2009 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is allowed from 11:00am until 5:00pm. Stack burning is not allowed. Weather Discussion: Daily high temperature records were broken Wednesday afternoon in Portland (97 degrees), Salem (99 degrees), and Eugene (101 degrees). The combination of high temperatures and low humidities put the valley into State Fire Marshal Conditions during the mid-to-late afternoon period Wednesday. The strong ridge of high pressure that brought the record warmth has moved east and was centered over western Idaho this morning. Increasing south-southwesterly flow aloft allowed a minor intrusion of cooler marine air into the Willamette Valley overnight. Temperatures cooled into the 50s across most of the valley, and some marine low clouds were even able to penetrate into the extreme north and extreme south valley. Satellite imagery showed a solid blanket of low clouds along both the Washington and Oregon coastlines...poised to be driven inland by increasing onshore flow. The mid-morning ODA surface analysis showed the thermal trough had shifted east, into central Oregon...extending back into southwestern Oregon. The Willamette Valley had weak southwesterly gradients. Onshore flow will increase today...cooling valley temperatures back closer to normal and greatly improving ventilation conditions over western Oregon. That should allow for open burning this afternoon, with a significant surge of marine air forecast to invade western Oregon with low clouds and cooler temperatures tonight. Surface Winds: SW 5-10 this morning, W 5-12 this afternoon. Transport Winds: SW 8 this morning, WSW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 45. High Temperature: Salem\'s high temperature today will be near 85. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 37%. Sunrise/Sunset: Salem sunset tonight: 8:10pm; sunrise tomorrow: 6:22am. Extended Outlook: Increasing southwesterly flow aloft, and onshore flow at the surface, will continue the cooling trend across western Oregon on Friday. The influx of marine tonight will be strong enough overnight to make open burning unlikely Friday (due to gradient-stacking), but not impossible, as the transport wind directions will remain favorable, and another surge of marine air is expected Friday night. A weak trough is forecast to maintain a deep marine layer over western Oregon Saturday, with continued southwesterly flow aloft. Varying degrees of onshore flow will continue Sunday through Wednesday with little to no rainfall and seasonal temperatures. Tomorrow (21 Aug): Am Clouds...Partly Sunny in the Afternoon. 54/80 Sat (22 Aug): AM Clouds...Partly Sunny in the Afternoon. 53/79 Sun (23 Aug): AM Clouds. PM Sunshine. 51/80 Mon (24 Aug): AM Clouds...PM Sunshine. 52/84 Tue (25 Aug): AM Clouds...Partly Sunny. 53/81 Wed (26 Aug): AM Clouds...Partly Sunny. 54/82 Thu (27 Aug): AM Clouds...Partly Sunny. 54/84 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 21 09:00:35 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 21 Aug 2009 11:00:35 -0500 Subject: [willamette-fcst] Forecast - Friday, August 21st, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 21st, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 7:30pm. 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: Increasing south-southwesterly flow aloft pushed the surface thermal trough east of the Cascades Thursday. A significant surge of cool marine air poured into the Willamette Valley Thursday and Thursday night. After topping out near the century mark Wednesday, valley highs cooled into the low to mid 80s Thursdsay. By this morning, the marine layer had deepened to about 3700 feet thick over the Willamette Valley. Visible satellite imagery showed low clouds had pushed inland and extended from the coast to the crest of the Cascades. Skies were mostly clear over extreme southwestern Oregon and east of the Cascades. There were a few high clouds over northeastern Oregon, in association with the weak weather system that intiated the onshore flow. Onshore flow will continue today, cooling valley temperatures a few more degrees. Morning clouds should give way to some sunshine this afternoon, but highs will struggle to reach 80 degrees. Mixing heights will climb to the top of the marine layer by about noon, which will allow for some propane flaming and limited prep burning. As expected, the marine push overnight has created gradient-stacking conditions this morning, with about 3 millabars more onshore gradient east of The valley than west of the valley. The unbalance in gradients will likely increase later this morning, as central Oregon heats up, and the western valleys stay cool under cloud-cover. It is doubtful that the western valleys will get enough afternoon heating to overcome that much gradient-stacking. However, a little stronger weather system, about 150 miles offshore at mid-morning, is forecast to move onshore late this afternoon. There is a slight chance that the timing of that system may help reverse the gradient-stacking, late this afternoon, which could give the north-valley a burning opportunity with north-northwesterly transport winds. Surface Winds: N 3-8 this morning, W 5-12 this afternoon. Transport Winds: N 5 this morning, NNW 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3700 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 81. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 41%. Sunrise/Sunset: Salem sunset tonight: 8:08pm; sunrise tomorrow: 6:23am. Extended Outlook: A weak trough is forecast to maintain southwesterly flow aloft and onshore flow at the surface, over western Oregon, Saturday and Sunday. A transitory ridge will bring more sunshine and some warming Monday, before another weak trough increases the onshore flow again by late Tuesday. That transition could be enough to create a burning opportunity Tuesday afternoon. Another transitory ridge is forecast for next Wednesday and Thursday, following by increasing onshore flow by Friday. Tomorrow (22 Aug): AM Clouds...PM Sunshine. 53/80 Sun (23 Aug): AM Clouds. PM Sunshine. 51/79 Mon (24 Aug): Brief AM Clouds...Mostly Sunny and Warmer. 50/83 Tue (25 Aug): Mostly Sunny. Increasing Onshore Flow in the Afternoon. 51/79 Wed (26 Aug): AM Clouds...Afternoon Sunshine and Warmer. 54/85 Thu (27 Aug): Mostly Sunny and Warm. 54/87 Fri (28 Aug): Increasing Clouds and Cooler. 54/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 21 09:07:30 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 21 Aug 2009 11:07:30 -0500 Subject: [willamette-fcst] Forecast - Friday, August 21st, 2009 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 Surface Winds Today... Issued: Friday, August 21st, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 7:30pm. 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: Increasing south-southwesterly flow aloft pushed the surface thermal trough east of the Cascades Thursday. A significant surge of cool marine air poured into the Willamette Valley Thursday and Thursday night. After topping out near the century mark Wednesday, valley highs cooled into the low to mid 80s Thursdsay. By this morning, the marine layer had deepened to about 3700 feet thick over the Willamette Valley. Visible satellite imagery showed low clouds had pushed inland and extended from the coast to the crest of the Cascades. Skies were mostly clear over extreme southwestern Oregon and east of the Cascades. There were a few high clouds over northeastern Oregon, in association with the weak weather system that intiated the onshore flow. Onshore flow will continue today, cooling valley temperatures a few more degrees. Morning clouds should give way to some sunshine this afternoon, but highs will struggle to reach 80 degrees. Mixing heights will climb to the top of the marine layer by about noon, which will allow for some propane flaming and limited prep burning. As expected, the marine push overnight has created gradient-stacking conditions this morning, with about 3 millabars more onshore gradient east of The valley than west of the valley. The unbalance in gradients will likely increase later this morning, as central Oregon heats up, and the western valleys stay cool under cloud-cover. It is doubtful that the western valleys will get enough afternoon heating to overcome that much gradient-stacking. However, a little stronger weather system, about 150 miles offshore at mid-morning, is forecast to move onshore late this afternoon. There is a slight chance that the timing of that system may help reverse the gradient-stacking, late this afternoon, which could give the north-valley a burning opportunity with north-northwesterly transport winds. Surface Winds: N 3-8 this morning, NNW 5-15 this afternoon. Transport Winds: N 5 this morning, NNW 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3700 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 81. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 41%. Sunrise/Sunset: Salem sunset tonight: 8:08pm; sunrise tomorrow: 6:23am. Extended Outlook: A weak trough is forecast to maintain southwesterly flow aloft and onshore flow at the surface, over western Oregon, Saturday and Sunday. A transitory ridge will bring more sunshine and some warming Monday, before another weak trough increases the onshore flow again by late Tuesday. That transition could be enough to create a burning opportunity Tuesday afternoon. Another transitory ridge is forecast for next Wednesday and Thursday, following by increasing onshore flow by Friday. Tomorrow (22 Aug): AM Clouds...PM Sunshine. 53/80 Sun (23 Aug): AM Clouds. PM Sunshine. 51/79 Mon (24 Aug): Brief AM Clouds...Mostly Sunny and Warmer. 50/83 Tue (25 Aug): Mostly Sunny. Increasing Onshore Flow in the Afternoon. 51/79 Wed (26 Aug): AM Clouds...Afternoon Sunshine and Warmer. 54/85 Thu (27 Aug): Mostly Sunny and Warm. 54/87 Fri (28 Aug): Increasing Clouds and Cooler. 54/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 21 11:50:09 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 21 Aug 2009 13:50:09 -0500 Subject: [willamette-fcst] Forecast - Friday, August 21st, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. NOON UPDATE Issued: Friday, August 21st, 2009 at 11:50am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 7:30pm. 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: late-morning visible satellite imagery showed low clouds continuing to blanket western Washington and northwestern Oregon. There were even pockets of drizzle in the Willamette Valley earlier this morning. The low clouds were beginning to clear away from the southern half of the Oregon Coast and coastal range. Surface observations and pilot reports show the low clouds over the Willamette Valley are about 2000 feet thick...extending up to between 3500 and 4000 feet. They should persist until the mid to late afternoon, so I have lowered my high temperature forecast a few degrees. Skies were sunny over extreme southwestern Oregon and east of the Cascades. Late-morning temperatures were in the low to mid 60s, under cloudy skies, across the Willamette Valley. Mixing heights will climb to the base of the low clouds, around 3000 feet, when surface temperatures reach the upper 60s early this afternoon. That will allow for some propane flaming and limited prep burning. As expected, the marine push overnight has created gradient-stacking conditions, which worsened from 3 millibars to more than 4 millibars, as the morning progressed. Normally, that would be too much gradient-stacking to reverse with afternoon heating. However, a weak cold front is forecast to move onshore late this afternoon. It may help to break up the marine low clouds and increase the onshore gradients west of the valley. There is a slight chance that the approaching dry cold front could create a brief burning opportunity in the north valley, since transport winds are forecast to be north-northwesterly. Winds will likely be too northerly for open burning, in the south valley, even if the gradient-stacking is reversed. We plan to begin pibals at 1pm. Surface Winds: NNW 5-15 this afternoon. Transport Winds: NNW 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3700 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 77. Humidities: Relative humidity drops to 50% around 2pm. Minimum relative humidity will be near 46%. Sunrise/Sunset: Salem sunset tonight: 8:08pm; sunrise tomorrow: 6:23am. Extended Outlook: A weak trough is forecast to maintain southwesterly flow aloft and onshore flow at the surface, over western Oregon, Saturday and Sunday. A transitory ridge will bring more sunshine and some warming Monday, before another weak trough increases the onshore flow again by late Tuesday. That transition could be enough to create a burning opportunity Tuesday afternoon. Another transitory ridge is forecast for next Wednesday, following by increasing onshore flow Thursday and Friday. Tomorrow (22 Aug): AM Clouds...PM Sunshine. 53/80 Sun (23 Aug): AM Clouds. Partly Sunny in the Afternoon. 51/79 Mon (24 Aug): Brief AM Clouds...Mostly Sunny and Warmer. 50/83 Tue (25 Aug): Mostly Sunny. Increasing Onshore Flow in the Afternoon. 51/79 Wed (26 Aug): AM Clouds...Afternoon Sunshine and a Touch Warmer. 54/83 Thu (27 Aug): Mostly Sunny. Onshore Flow Possibly Increasing Late. 54/85 Fri (28 Aug): Mostly Cloudy and Cooler. Chance of AM Drizzle. 54/77 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 24 08:54:38 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 24 Aug 2009 10:54:38 -0500 Subject: [willamette-fcst] Forecast - Monday, August 24th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, August 24th, 2009 at 8:55am. 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 upper-level ridge of high pressure is over Oregon this morning. Visible satellite imagery shows mostly clear skies over the state. There are some low clouds extending from the extreme north coast up the Columbia River to the Portland area. Mid-morning temperatures were mostly in the upper 40s and 50s statewide. The upper-level ridge is forecast to shift over Idaho this afternoon, with increasing southwesterly flow aloft. Continued sunny skies should warm valley temperatures in to the low 80s this afternoon. Light winds forecast through early this afternoon. However, ventilation conditions are forecast to improve later this afternoon, likely allowing for open burning in both the north and south valley. Daytime heating should lift mixing heights above 4000 feet, with an approaching cold front increasing the southwesterly transport winds. The front is forecast to move onshore overnight, with a good chance of light rain along the coast and possibly some drizzle or very light rain in the Willamette Valley Tuesday morning...mainly from Salem north. Surface Winds: Var 0-6 this morning, W 5-10 this afternoon. Transport Winds: NE 5 this morning, SW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 45. High Temperature: Salem\'s high temperature today will be near 82. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 30%. Sunrise/Sunset: Salem sunset tonight: 8:03pm; sunrise tomorrow: 6:26am. Extended Outlook: After a chance of very light rain or drizzle the morning, skies should begin to clear Tuesday afternoon. Onshore flow will cool valley high temperatures into the low to mid 70s. The flow aloft will weaken, and turn more southerly, Wednesday and Thursday, as a strong upper-level ridge rebuilds over the region. Temperatures should quickly warm back above normal, under mostly sunny skies. A weakening Pacific cold front is forecast to brush by to our north Friday, but it should be strong enough to increase the onshore flow and cool temperatures back to near-normal. It may also create an open burning opportunity Friday afternoon. The upper-level ridge is forecast to quickly rebuild over the region this weekend. Tue (25 Aug): Chance of Light AM Rain...Mainly North. Partial Afternoon Clearing. 51/73 Wed (26 Aug): Becoming Mostly Sunny and Warmer. 51/86 Thu (27 Aug): Sunny and Warm. 53/87 Fri (28 Aug): Partly Cloudy and Cooler. 54/80 Sat (29 Aug): Sunny and Warmer. 53/87 Sun (30 Aug): Sunny and Very Warm. 55/91 Mon (31 Aug): Sunny and Warm. Increasing onshore flow in the afternoon. 55/86 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 24 09:14:00 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 24 Aug 2009 11:14:00 -0500 Subject: [willamette-fcst] Forecast - Monday, August 24th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, August 24th, 2009 at 8:55am. 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 upper-level ridge of high pressure is over Oregon this morning. Visible satellite imagery shows mostly clear skies over the state. There are some low clouds extending from the extreme north coast up the Columbia River to the Portland area. Mid-morning temperatures were mostly in the upper 40s and 50s statewide. The upper-level ridge is forecast to shift over Idaho this afternoon, with increasing southwesterly flow aloft. Continued sunny skies should warm valley temperatures in to the low 80s this afternoon. Light winds forecast through early this afternoon. However, ventilation conditions are forecast to improve later this afternoon, likely allowing for open burning in both the north and south valley. Daytime heating should lift mixing heights above 4000 feet, with an approaching cold front increasing the southwesterly transport winds. The front is forecast to move onshore overnight, with a good chance of light rain along the coast and possibly some drizzle or very light rain in the Willamette Valley Tuesday morning...mainly from Salem north. Surface Winds: Var 0-6 this morning, W 5-10 this afternoon. Transport Winds: NE 5 this morning, SW 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 45. High Temperature: Salem\'s high temperature today will be near 82. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 30%. Sunrise/Sunset: Salem sunset tonight: 8:03pm; sunrise tomorrow: 6:26am. Extended Outlook: After a chance of very light rain or drizzle the morning, skies should begin to clear Tuesday afternoon. Onshore flow will cool valley high temperatures into the low to mid 70s. The flow aloft will weaken, and turn more southerly, Wednesday and Thursday, as a strong upper-level ridge rebuilds over the region. Temperatures should quickly warm back above normal, under mostly sunny skies. A weakening Pacific cold front is forecast to brush by to our north Friday, but it should be strong enough to increase the onshore flow and cool temperatures back to near-normal. It may also create an open burning opportunity Friday afternoon. The upper-level ridge is forecast to quickly rebuild over the region this weekend. Tue (25 Aug): Chance of Light AM Rain...Mainly North. Partial Afternoon Clearing. 51/73 Wed (26 Aug): Becoming Mostly Sunny and Warmer. 51/86 Thu (27 Aug): Sunny and Warm. 53/87 Fri (28 Aug): Partly Cloudy and Cooler. 54/80 Sat (29 Aug): Sunny and Warmer. 53/87 Sun (30 Aug): Sunny and Very Warm. 55/91 Mon (31 Aug): Sunny and Warm. Increasing onshore flow in the afternoon. 55/86 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Aug 25 08:46:49 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 25 Aug 2009 10:46:49 -0500 Subject: [willamette-fcst] Forecast - Tuesday, August 25th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Tuesday, August 25th, 2009 at 8:45am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 2:00pm until 7:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A weak cold front was pusing onto the Oregon Coast this morning, with areas of sprinkles and very light rain spreading into the northern Willamette Valley, as far south as Salem, by mid-morning. Satellite imagery showed cloudy skies covering virtually all of western Washington and much of northwestern Oregon...with the leading edge of the cloud-shield advancing to the Cascades as far south as Lane County. CoCoRaHS reports indicated only trace amounts, to a couple hundredths of an inch, of rain had fallen in Marion County as of mid-morning. The front will bring areas of sprinkles or very light rain to sections of the Willamette Valley, as it pushes across northwestern Oregon this morning and early this afternoon. Some clearing is likely later this afternoon, but it will be cooler, with valley highs only climbing into the mid 70s. Cooler surface temperatures will keep mixing heights below 3000 feet until this afternoon, when transport winds are forecast to become northerly. The combination of locally damp conditions (mainly north valley), forecast northerly transport winds this afternoon, and significant gradient-stacking makes open burning unlikely today. Surface Winds: S 5-10 this morning, NNW 5-10 this afternoon. Transport Winds: SSW 6 this morning, N 6 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 21. High Temperature: Salem\'s high temperature today will be near 75. Humidities: Relative humidity drops to 50% around 2pm. Minimum relative humidity will be near 40%. Sunrise/Sunset: Salem sunset tonight: 8:01pm; sunrise tomorrow: 6:28am. Extended Outlook: The flow aloft will weaken, and turn more southerly, Wednesday and Thursday, as a strong upper-level ridge rebuilds over the region. Temperatures should quickly warm back above normal, under mostly sunny skies. Transport winds will likely be too southerly for open burning in the north valley. There may be enough of a southwesterly component to the transport winds for limited open burning, in the south valley, Wednesday. The transport winds are forecast to become almost due southerly by Thursday, which would not allow for any open burning. A weakening Pacific cold front is forecast to brush by to our north Friday, but it should be strong enough to increase the onshore flow and cool temperatures about 10 degrees or more. If it doesn\'t come onshore too quickly Friday, it may create an afternoon burning opportunity, provided that the transport winds are not too southerly. The upper-level ridge is forecast to quickly rebuild over the region this weekend, with temperatures possibly shooting into the 90s by Sunday. Cooling is expected early next week, as a trough drops southeastward, from the Gulf of Alaska. That may create a burning opportunity, as the onshore flow increases Monday afternoon. The marine layer will likely deepen Tuesday, as the upper-level trough swings inland. That system appears as if it will by dry, this far south, but there is a slight chance for light showers in the north valley by late Tuesday. Tomorrow (26 Aug): Becoming Mostly Sunny and Warmer. 51/87 Thu (27 Aug): Sunny and Warm. 53/90 Fri (28 Aug): Increasing Clouds and Cooler. Chance of Sprinles North. 56/79 Sat (29 Aug): Mostly Sunny and Warmer. 55/87 Sun (30 Aug): Sunny and Very Warm. 55/91 Mon (31 Aug): Mostly Sunny and Warm. Increasing onshore flow in the afternoon. 55/86 Tue (01 Sep): Partly Cloudy and Cooler. Slight Chance of Sprinkles North. 53/81 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Aug 26 09:01:28 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 26 Aug 2009 11:01:28 -0500 Subject: [willamette-fcst] Forecast - Wednesday, August 26th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, August 26th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 2:00pm until 7:00pm. Preparatory burning is not allowed. Propane flaming is allowed from 2:00pm until 5:00pm. Straw stack burning is allowed from 2:00pm until 7:00pm. Weather Discussion: An upper-level ridge of high pressure will rebuild over Oregon today, with southwesterly flow aloft decreasing and becoming more southerly. Satellite imagery showed mostly clear skies over Oregon this morning, except for some high clouds over mainly the northwestern corner of the state. Mid-morning temperatures were mostly in the low to mid 50s, across western Oregon, with light north to northeasterly surface winds. With warmer air aloft, and sunny skies today, Willamette Valley highs should climb into the mid to upper 80s. Surface Winds: NE 0-5 this morning, NNW 5-10 this afternoon. Transport Winds: NE 8 this morning, SSW 6 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 32. High Temperature: Salem\'s high temperature today will be near 87. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 22%. Sunrise/Sunset: Salem sunset tonight: 7:59pm; sunrise tomorrow: 6:29am. Extended Outlook: The flow aloft will continue to weaken, and turn almost due southerly on Thursday, as a strong upper-level ridge builds over Idaho and western Montana. Temperatures should warm a few more degrees over the interior of western Oregon, under mostly sunny skies. Transport winds will likely be too southerly for open burning. A weakening Pacific cold front is forecast push into the strong ridge and make it onshore Friday, with enough moisture to likely bring some light rain to the Oregon Coast. Some light rain could make it inland into the Willamette Valley Friday afternoon, but that is questionable at this time. Depending on the timing of this system, it may create a burning opportunity Friday afternoon. However, the flow aloft is forecast to remain southerly, which does not vavor open burning chances. A weak cut-off upper-level low-pressure area is forecast to remain over Wahington and Oregon Saturday, before moving into Idaho Sunday. A broad and strong upper-level ridge will remain anchored over the remainder of western North America. Temperatures will slowly climb back above normal by Sunday, across western Oregon, with increasing amounts of sunshine. Increasing southwesterly flow aloft will develop Monday, as a trough drops southeastward, from the Gulf of Alaska. That may create a burning opportunity Monday afternoon, if the system approaches the coastline quickly enough. High temperatures may warm a degree or two more, on Monday, before onshore flow increases late in the day. Onshore flow will likely increase Tuesday and Wednesday, as the upper-level trough approaches the coastline. If the winds aloft are not too southerly, that may also create a burning opportunity. Tomorrow (27 Aug): Sunny and Warm. 53/90 Fri (28 Aug): Increasing Clouds and Cooler. Chance of PM Sprinles or Light Rain. 56/79 Sat (29 Aug): Partly Cloudy. 54/81 Sun (30 Aug): Mostly Sunny and Warmer. 53/85 Mon (31 Aug): Mostly Sunny and Warm. Increasing onshore flow in the afternoon. 54/86 Tue (01 Sep): Mostly Sunny. A Little Cooler. 54/82 Wed (02 Sep): Partly Cloudy. 52/79 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Aug 27 09:00:37 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 27 Aug 2009 11:00:37 -0500 Subject: [willamette-fcst] Forecast - Thursday, August 27th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, August 27th, 2009 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, centered over Idaho, will bring a sunny and warmer day to the interior of western Oregon today. The Salem sounding this morning showed further warming alost, since Wednesday afternoon, so high temperatures will likely warm into the low 90s, after topping out in the mid to upper 80s Wednesday. Mixing heights only climbed to around 3000 feet Wednesday and should be even lower today. The combinatin of light surface winds, weak southerly flow aloft, and low mixing heights will make for poor ventilation conditions over the Willamette Valley. Surface Winds: S 2-6 this morning, SW 4-8 this afternoon. Transport Winds: SSE 4 this morning, SW 5 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2700 feet. Ventilation index 14. High Temperature: Salem\'s high temperature today will be near 92. Humidities: Relative humidity drops to 50% around 10am. Minimum relative humidity will be near 20%. Sunrise/Sunset: Salem sunset tonight: 7:58pm; sunrise tomorrow: 6:30am. Extended Outlook: A weakening Pacific cold front is forecast push into the strong ridge and swing onshore Friday. It appears as if this system will have enough moisture to bring some light rain to the coast by Friday afternoon, with a good chance of light rain in the Willamette Valley by Friday evening. Ahead of it, continued southerly flow aloft will likely keep mixing heights suppressed, over western Oregon, Friday, making a burning opportunity unlikely. Increasing clouds and onshore flow should knock 10-15 degrees off of valley high temperatures Friday, compared to this afternoon. The incoming weather system is forecast to stall over Washington and Oregon this weekend...forming an upper-level low-pressure area over the region...cut off from the main circulatino pattern. These types of systems tend to be very slow moving, with this one forecast to drift into eastern Oregon by Sunday afternoon. That will bring slow drying and warming to areas west of the Cascades, while maintaining a good chance of showers over the eastern third of the state. The upper-level low-pressure area is forecast to finally push into Idaho Monday with weak south-southwesterly flow aloft returning to western Oregon during the first half of next week. That should bring mostly sunny skies and above normal temperatures to the Willamette Valley. The thermal trough is forecast to stay east of the Cascades, with weak onshore flow possibly allowing for some burning opportunities. Tomorrow (28 Aug): Increasing Clouds and Cooler. Chance of Showers by Evening. 56/78 Sat (29 Aug): Mostly Cloudy. Chance of Showers...Decreasing Late. 55/78 Sun (30 Aug): Becoming Mostly Sunny and Warmer. 53/83 Mon (31 Aug): Mostly Sunny. 54/86 Tue (01 Sep): Mostly Sunny. 54/88 Wed (02 Sep): Mostly Sunny. 54/85 Thu (03 Sep): Mostly Sunny. 53/85 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Aug 28 09:02:57 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 28 Aug 2009 11:02:57 -0500 Subject: [willamette-fcst] Forecast - Friday, August 28th, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, August 28th, 2009 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 weak Pacific cold front, about 200 miles off the Oregon Coast this morning, is entraining moisture from an old tropical storm. Doppler radar showed some impressive rainfall moving northward, just off the central Oregon Coast at mid-morning. Surface reports showed light rain had moved onshore along the southern Oregon Coast, at Brookings. Skies were mostly cloudy along the remainder of the coast, with middle & high clouds filtering the sunshine over the Willamette Valley. The mid-morning ODA surface analysis showed the thermal trough had shifted east of the Cascades in northern Oregon. It extended from south-central Washington, through central Oregon, then southwestward into southwesern Oregon. Winds were light and variable across the Willamette Valley with surface temperatures ranging from the mild upper 50s to mid 60s. Increasing onshore flow and clouds will likely cap Willamette Valley highs temperatures near 80 degrees this today, after peaking in the low 90s Thursday. The Salem sounding this morning showed very little temperature change compared with Thursday morning, so the air mass aloft remains very warm this morning. With a cooler surface and continued very warm air aloft today, mixing heights may not climb much above 2500 feet this afternoon. That may inhibit open burning possibilities, even if increasing onshore flow turns transport winds in a favorable westerly direction. In addition, moisture will continue to circulate northward, into the slowly approaching frontal zone, with the chance for rain showers increasing today...mainly along the coast. The bulk of the rainfall from this system is forecast to stay just offshore, but some showers could migrate as far east as the Cascades this afternoon. Surface Winds: Var 5 this morning, W 4-8 this afternoon. Transport Winds: Var 5 this morning, NW 6 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2800 feet. Ventilation index 17. High Temperature: Salem\'s high temperature today will be near 80. Humidities: Minimum relative humidity will be near 34%. Sunrise/Sunset: Salem sunset tonight: 7:56pm; sunrise tomorrow: 6:31am. Extended Outlook: The weather system is forecast to slowly cut across Washington Saturday, before dropping southeastward, across northeastern Oregon, and into central Idaho by Sunday. The Willamette VAlley will continue to have a threat of showers through Saturday night, before drying out and warming up Sunday. The Willamette Valley will likely miss out on the bulk of the rain from this system, but it could produce some locally impressive amounts along the coastline, across Washington and into northeastern Oregon, over the next 72 hours. The associated upper-level low-pressure area is forecast to finally push into Idaho Monday with weak south-southwesterly flow aloft returning warmer and drier weather to western Oregon for much of next week, with temperatures climbing slightly above normal across the Willamette Valley. The thermal trough is forecast to stay east of the Cascades, with weak onshore flow possibly allowing for some burning opportunities. The next significant weather system is forecast to come onshore late next week. Tomorrow (29 Aug): Mostly Cloudy. Chance of Showers...Decreasing Late. 55/78 Sun (30 Aug): Becoming Mostly Sunny and Warmer. 55/83 Mon (31 Aug): Mostly Sunny. 55/86 Tue (01 Sep): Mostly Sunny. 55/85 Wed (02 Sep): Mostly Sunny. 55/84 Thu (03 Sep): Mostly Cloudy and Cooler. Chance of Showers. 55/76 Fri (04 Sep): Mostly Cloudy. Chance of Showers. 52/72 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Aug 31 09:01:45 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 31 Aug 2009 11:01:45 -0500 Subject: [willamette-fcst] Forecast - Monday, August 31st, 2009 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, August 31st, 2009 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 50 acre limit. Propane flaming is allowed from 12:00pm until 5:00pm. Stack burning is not allowed. Weather Discussion: The upper-level trough that brought showers to the region late last week, and over the weekend, will continue to bring showers and thudnerstorms to much of central and eastern Idaho today. The next system is still a ways upstream and was dropping southeastward, from the Gulf of Alaska, off the British Columbia coastline. Inbetween the two, Oregon and Washington will have fair weather today. Visible satellite imagery showed low clouds covering much of the coastline this morning, with patchy low clouds in the Willamette Valley...especially from Salem north. Skies were mostly clear over southwestern Oregon and areas east of the Cascades, with the exception of some clouds near the Idaho border in northeastern Oregon. The ODA surface analysis showed a weak trough across central Washington...extending through central Oregon and into southwestern Oregon. High pressure was nosing into western Washington with a weak north-northesterly flow across western Oregon. With a consierable northerly component to the low-level flow, skies should slowly clear along the coast later today, with mostly sunny skies expected across the Willamette Valley. Highs should climb into the mid to upper 60s along the coast and low to mid 80s in the Willamette Valley. Forecast north-northeasterly transport winds may allow for limited open burning, in the extreme western portion of the south valley, later this morning. The transport winds are forecast to become almost due northerly this afternoon, which is not conducive to open burning in the Willamette Valley. Surface Winds: N 5-10 this morning, NNW 7-15 this afternoon. Transport Winds: N 10 this morning, N 13 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4000 feet. Ventilation index 52. High Temperature: Salem\'s high temperature today will be near 83. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 38%. Sunrise/Sunset: Salem sunset tonight: 7:50pm; sunrise tomorrow: 6:35am. Extended Outlook: The Gulf of Alaska weather system is forecast to drops south-southeastward...staying well offshore Tuesday...slowly approaching the coastline Wednesday. South-southwesterly flow aloft will increase over Washington and Oregon, with some increase in onshore flow at the surface. That will likely cool valley temperature a couple of degrees and turn transport winds more westerly. That may create an open burning opportunity Tuesday and/or Wednesday afternoon. That system is forecast to finally come onshore late Wedneday and early Thursday...bring a chance of showers to mainly western Washington and northwestern Oregon. It appears that the best chance of showers in the Willamette Valley will be from about Salem north. Some clearing is expected Thursday afternoon, as a transitory ridge moves over the region. The next system appears stronger and is forecast to come onshore Friday. It appears likely that this system will be strong enough to bring showers to the entire Willamette Valley, but the timing of the onset of rain is still very much in question. If the system comes onshore late enough, there could be burning opportunity, ahead of it, Friday afternoon. A cool upper-level trough is forecast to swing onshore Satruday and Sunday, maintaining below normal temperatures and a chance of showers. A dry northwesterly flow aloft is forecast for Labor Day. Tomorrow (01 Sep): Areas of AM Clouds. Afternoon Sunshine. 55/81 Wed (02 Sep): Areas of AM Clouds. Afternoon Sunshine. Chance of Showers Late. 54/81 Thu (03 Sep): Chance of AM Showers...Mainly North. Partly Cloudy in the Afternoon. 54/77 Fri (04 Sep): Increasing Clouds. Rain Likely by Evening. 53/77 Sat (05 Sep): Mostly Cloudy and Cool. Chance of Showers. 52/71 Sun (06 Sep): Mostly Cloudy and Cool. Chance of Showers. 51/72 Mon (07 Sep): Becoming Mostly Sunny and Warmer in the Afternoon. 49/77 ODA Meteorologist weather at oda.state.or.us