From willamette-fcst at listsmart.osl.state.or.us Wed Jul 1 09:15:22 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 01 Jul 2009 11:15:22 -0500 Subject: [willamette-fcst] Forecast - Wednesday, July 1st, 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 this afternoon... Issued: Wednesday, July 1st, 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 ridge trying to build over the Pacific Northwest is still being flattened by a trough cutting across southern British Columbia and Alberta, Canada. With the main jet stream over southwestern Canada, Washington and Oregon continue to be under a dry westerly flow aloft. Surface gradients have completed a turn from onshore to due northerly, with no marine low clouds this morning...even along the Washington and Oregon coastlines. Clear skies and dry air over the region allowed temperatures to drop below normal across Oregon again this morning. Tillamook and Newport both dipped to 41 degrees. Willamette Valley minimums dropped mostly into the 40s, with McMinnville dipping to 42 degrees. Meacham was the cold spot in the state, for the third straight morning, with a minimum at the freezing mark (32 degrees). Northerly winds increased again Tuesday afternoon, with gusts to near 40 mph along the central and southern coast and to 30 mph in the southern Willamette Valley. The overall weather pattern is not much different today, except for several degrees of warming aloft, as seen on the morning sounding over Salem. Therefore, daytime heating will, once again, force the increase of northerly winds this afternoon, with gusts over 35 mph likely along the coastal strip and to near 30 mph in the southern Willamette Valley. North wind gusts in the 15-25 mph range are expected this afternoon in the northern Willamette Valley...much like Tuesday afternoon. The combination of low humidity levels and increasing northerly winds will likely put much of the Willamette Valley into Fire Marshal conditions this afternoon. Warmer air aloft will also make for lower mixing heights today, so agricultural burning is not recommended. With a full day of early July sunshine and warmer air aloft, valley highs should climb into the upper 80s, after peaking near 80 Tuesday afternoon. Coastal highs will warm into the upper 60s and 70s, along with those brisk northerly winds. Temperatures east of the Cascades will range from the upper 70s to the low 90s, with the warmest readings near the Idaho border. Surface Winds: N 5-15 this morning, N 10-20 G30 south this afternoon. Transport Winds: NNE 15 this morning, N 20 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 60. High Temperature: Salem\'s high temperature today will be near 88. Humidities: Minimum relative humidity will be near 22%. Sunrise/Sunset: Salem sunset tonight: 9:02pm; sunrise tomorrow: 5:30am. Extended Outlook: Not much change is forecast in the weather pattern Thursday. The jet stream is forecast to migrate slightly farther north, with another couple degrees of warming aloft. A surface thermal trough will build northward into Oregon with northerly presure gradients relaxing. Willamette Valley temperatures should climb to near 90 Thursday afternoon, with weak southwesterly flow aloft introducing a slight chance of late-day thunderstorms over extreme southern Oregon. Increasing southwesterly flow aloft will likely shift the broad surface thermal trough just far enough eastward to prevent western Oregon temperatures from warming much more...if any. The threat of afternoon thunderstorms will increase across southern and eastern Oregon with continued warming temperatures there. A very weak upper-level trough will bring some westerly flow aloft to Oregon Saturday, with increasing onshore flow cooling temperatures a touch west of the Cascades. It will still be a very warm day, however, with a chance of thundershowers continuing across southern and eastern Oregon. A stronger trough is forecast to approach the coastline Sunday, turning the flow aloft southwesterly and initiating a significant marine push late in the day. There may be enough moisture introduced into the region for showers or thundershowers during this transition to a cooler air mass. The cooling trend will continue Monday and Tuesday, with a chance of showers. The trough is forecast to weaken, as it stalls over the region Tuesday and Wednesday. Tomorrow (02 Jul): Sunny and Very Warm. 50/91 Fri (03 Jul): Mostly Sunny and Very Warm. 53/92 Sat (04 Jul): Mostly Sunny and Very Warm. 53/89 Sun (05 Jul): Becoming Mostly Cloudy and Cooler. Chance of Showers or T-Storms. 53/77 Mon (06 Jul): Mostly Cloudy and Much Cooler. Chance of Showers. 53/70 Tue (07 Jul): Mostly Cloudy. Slight Chance of Showers. 52/72 Wed (08 Jul): Mostly Cloudy. Slight Chance of Showers. 53/75 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Jul 2 09:14:14 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 02 Jul 2009 11:14:14 -0500 Subject: [willamette-fcst] Forecast - Thursday, July 2nd, 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 May Be Reached This Afternoon... Issued: Thursday, July 2nd, 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 ridge over the region built slightly further north Wednesday with the associated surface thermal trough pushing orthward, as well, into western Oregon. That helped temperatures climb into the mid 70s along the northern Oregon Coast and upper 80s to low 90s in the Willamette Valley. Southwestern Oregon temperatures reached the upper 90s. Very dry and fairly brisk northerly winds, gusting to 25 mph, lowered relative humidity levels well below 30% Wednesday afternoon, resulting in Fire Marshal conditions across most of the Willaemette Valley. With a very dry air mass in place, clear skies overnight allowed for strong radiational cooling, and temperatures dropped back into the 40s and 50s across western Oregon. Newport dipped to 43 degrees, with Tillamook and Astoria dropping to 45 and 46 degrees respectively. McMinnille was the cold spot in the Willamette Valley this morning with a minimum of 46 degrees. Portland was the warm spot, due to the urban heat-island effect, with a minumum of 63 degrees. Most of the Willamette Valley dropped into the low to mid 50s. Sunny skies east of the Cascades Wednesday lifted temperatures into the 80s and low 90s. There was a wide range of temperatures across central and eastern Oregon this morning...ranging from a minimum of 35 degrees in Meacham to a balmy low of 58 degrees in Ontario. The upper-level ridge is contining to build over the region. The morning sounding over Salem showed a couple of more degrees of warming aloft, between 3000 and 7000 feet, compared with Wednesday, so surface temperatures should also be a few degrees warmer this afternoon. The ODA surface analysis showed a broad thermal trough extending northward, from California, clear into southwestern Washington. That has relaxed the northerly pressure gradients across western Oregon. The winds had turned onshore along the southern Oregon Coast, with visible satellite imagery showing coastal low clouds and fog advancing northward to about Cape Blanco. Sunny skies covered the remainder of the state. Light Southwesterly flow aloft was circulating some mid and high-level clouds across south-central and eastern Oregon. Daytime heating will intensify the thermal trough over western Oregon, especially over the southwest interior. That will produce some increase in northerly winds from the north coast to the southwestern valleys, again, this afternoon. However, winds should not be as strong as they have been the past few days...peaking around 15 mph in the Willamette Valley later this afternoon. The combination of low humidity levels, increasing northerly winds, and temperatures warming into the low to mid 90s may push sections of the Willamette Valley into Fire Marshal conditions again this afternoon. Warm air aloft will also keep mixing heights from climbing much above 3000 feet. The northern and central coast will also see sunny skies with not as much northerly wind today. Highs will peak in the upper 60s along the central coast and mid 70s along the north coast. Low clouds and fog could be quite persistent along the south coast with onshore flow holding temperatures in the 50s. Temperatures east of the Cascades will range from the upper 70s to the mid 90s, with the warmest readings near the Idaho border. Surface Winds: N 5-12 this morning, N 7-15 this afternoon. Transport Winds: NNE 7 this morning, N 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3200 feet. Ventilation index 38. High Temperature: Salem\'s high temperature today will be near 95. Humidities: Minimum relative humidity will be near 17%. Sunrise/Sunset: Salem sunset tonight: 9:02pm; sunrise tomorrow: 5:31am. Extended Outlook: Increasing westerly flow aloft will likely shift the broad surface thermal trough just far enough eastward to prevent western Oregon temperatures from warming much more, if at all, Friday and Saturday, but it will remain very warm. The warmest temperatures will likely shift east of the cascades with the threat of afternoon thunderstorms increasing across mainly southern and eastern Oregon Friday...shifting to near the Idaho border Saturday. A stronger trough is forecast to approach the coastline Sunday, turning the flow aloft southerly and initiating a significant marine push late in the day. There may be enough moisture introduced into the region for showers or thundershowers during this transition to a cooler air mass. Much cooler weather is forecast for Monday and Tuesday, with a chance of showers. The trough is forecast to weaken, as it stalls over the region Wednesday and Thursday. Tomorrow (03 Jul): Sunny and Very Warm. 55/95 Sat (04 Jul): Sunny and Very Warm. 56/95 Sun (05 Jul): Increasing Chance of Showers or T-Storms Late. 56/86 Mon (06 Jul): Mostly Cloudy and Much Cooler. Chance of Showers. 55/73 Tue (07 Jul): Mostly Cloudy. Chance of Showers. 53/72 Wed (08 Jul): Mostly Cloudy. Chance of Showers. 53/72 Thu (09 Jul): Partly Cloudy. 53/77 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Jul 2 11:55:21 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 02 Jul 2009 13:55:21 -0500 Subject: [willamette-fcst] Forecast - Thursday, July 2nd, 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 May Be Reached This Afternoon... Issued: Thursday, July 2nd, 2009 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: An upper-level ridge is contining to build over the region today. The morning sounding over Salem showed several degrees of warming aloft, between 3000 and 7000 feet, compared with Wednesday, so surface temperatures should also be warmer this afternoon. The late-morning ODA surface analysis showed a broad thermal trough extending northward, from southwestern Oregon, into southwestern Washington. That has relaxed the northerly pressure gradients across western Oregon with winds generally 10 mph or less as of late this morning. Temperatures had already warmed into the mid to upper 70s along the north coast and across the Willamette Valley. The low-level flow had turned onshore, south of Cape Blanco, on the southern Oregon Coast, with late-morning temperatures only in the 50s. That is typical of a developing heat-wave pattern across the interior of western Oregon. Visible satellite imagery showing coastal low clouds and fog along the northern California Coast, extending northward to the extreme southern Oregon Coast. Skies were sunny, with northerly winds, north of Cape Blanco. Highs will range from the mid to upper 60s, on the central coast, to well into the 70s along the north coast. Low clouds and fog could be quite persistent along the south coast with onshore flow holding temperatures in the 50s. Sunny skies covered the remainder of the state at midday, except for convective cloud development pushing northward, from Nevada, into south-central and southeastern Oregon. Radar was not showing any showers, yet, with these clouds, but a few should develop this afternoon, along with isolated thunderstorms. Some storms could produce strong gusty winds. Due to dry air in the low-levels of the atmosphere, these storms are not likely to produce much rain, with potential lightning increasing the wildfire risk. Temperatures east of the Cascades will range from the upper 70s to the mid 90s, with the warmest readings near the Idaho border. Daytime heating will intensify the thermal trough over western Oregon this afternoon, especially over the southwest interior. That will produce some increase in northerly winds along the north and central coast and across the Willamette Valley. However, winds winds not be as strong as they have been the past few days...peaking around 15 mph in the Willamette Valley later this afternoon. The combination of low humidity levels, increasing northerly winds, and hot temperatures (highs in the low to mid 90s) may push sections of the Willamette Valley into Fire Marshal conditions this afternoon. Surface Winds: N 7-15 this afternoon. Transport Winds: N 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3200 feet. Ventilation index 38. High Temperature: Salem\'s high temperature today will be near 95. Humidities: Minimum relative humidity will be near 17%. Sunrise/Sunset: Salem sunset tonight: 9:02pm; sunrise tomorrow: 5:31am. Extended Outlook: Increasing southwesterly flow aloft will likely shift the broad surface thermal trough just far enough eastward to allow some very weak onshore flow into western Oregon Friday and Saturday. That should keep high temperatures from climbing above the mid 90s, but it is going to remain very warm through the holiday weekend...especially east of the Cascades. There will continue to be a threat of isolated afternoon thunderstorms across mainly south-central and southeastern Oregon. A farily strong trough is forecast to approach the coastline Sunday, turning the flow aloft more southerly and shifting the surface thermal trough into eastern Oregon. That will initiate a significant marine push by late in the day. There may be enough upper-level energy and moisture for showers or thundershowers during this transition, mainly from the Cascades eastward. It is possible, if the flow aloft turns southerly enough, for thundershowers to develop over the Willamette Valley, but that is too far out to call. Long-range computer models show the strong upper-level trough moving over the Pacific Northwest early next week. Much cooler weather is forecast for Monday and Tuesday, with a chance of showers. The trough is forecast to weaken, as it stalls over the region Wednesday and Thursday. That would maintain onshore flow and below normal temperatures, with a continued risk of showers. Tomorrow (03 Jul): Sunny and Very Warm. 55/95 Sat (04 Jul): Sunny and Very Warm. 56/95 Sun (05 Jul): Increasing Chance of Showers or T-Storms Late. 56/86 Mon (06 Jul): Mostly Cloudy and Much Cooler. Chance of Showers. 55/73 Tue (07 Jul): Mostly Cloudy. Chance of Showers. 53/72 Wed (08 Jul): Mostly Cloudy. Chance of Showers. 53/72 Thu (09 Jul): Partly Cloudy. 53/76 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Jul 6 08:59:05 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 06 Jul 2009 10:59:05 -0500 Subject: [willamette-fcst] Forecast - Monday, July 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: Monday, July 6th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 11:00am until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A dry cold front shifted the windflow pattern to onshore Sunday and began a cooling trend across western Oregon. Willamette Valley highs Sunday topped out in the upper 70s and low 80s...about 10-15 degrees cooler than they were Thursday through Saturday. A significant push of cooler marine air surged inland overnight. Low clouds blanketed the western valleys this morning and should be quite persistent today. High temperatures will be another 10 degrees cooler today, with highs struggling to reach 70. The initial cold front was strong enough to bring some shower and thundershower activity to Washington state, which extending southward into northeastern Oregon Sunday evening. Pendleton and Meacham both picked up about one-tenth of an inch of rain and thunderstorms extended as far south and east as Baker City, with CoCoRaHs reports showing close to a tenth of an inch of rain falling is sections of northern Baker County. West of the Cascades, the northern and central coast loally picked up a couple hundredths of an inch of rain overnight with some sprinkles making it into the northwestern interior. The mid-morning ODA surface analysis showed the initial cold front moving into central Idaho, with cooler air spreading across of all of Oregon. Onshore pressure gradients were strongest east of the Cascades, with westerly winds were gusting to around 30 mph from Hermiston and Pendleton southweard to Rome. Winds had turning mostly southerly across the Willamette Valley and along the coast in the 5-15 mph range. Infrared satellite imagery showed a band of middle and high clouds, associated with the cold front, extending from eastern Washington to northeastern Oregon and a secondary line of middle and high clouds moving onto the Washington coast. Visible satellite imagery showed extensive low clouds covering all of western Washington and all but the extreme southern interior of western Oregon. Skies were sunny just east of the Cascades, across all of central and southeastern Oregon. Temperatures were generally in the mid to upper 50s across western Oregon and ranged from the mid 50s to the low 70s east of the Cascades. The warmest readings were along the Idaho border. Doppler radar showed scattered showers and a few thunderstorms over eastern Washington with a few light showers extending into extreme northeastern Oregon. Some light showers were also showing up over western Washington with possible sprinkles over northwestern Oregon, about as far south as Salem. The Salem sounding this morning showed massive cooling aloft, compared with Sunday morning, along with a saturated air mass between 3000 and 6500 feet (the thickness of the marine clouds). The upper-level trough responsible for the drastic change in the weather was centered over Vancouver Island, British Columbia this morning. Little movemove of this system is expected today wtih continued strong onshore flow both aloft and at the surface. The marine clouds should be quite persistent over the Willamette Valley today, with a chance of sprinkles this morning. High temperatures may not climb out the 60s across much of the valley this afternoon. If we get a few sunbreaks, then the low 70s are possible. Surface Winds: S 5-15 this morning, W 5-15 this afternoon. Transport Winds: SW 12 this morning, W 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 54. High Temperature: Salem\'s high temperature today will be near 68. Humidities: Minimum relative humidity will be near 51%. Sunrise/Sunset: Salem sunset tonight: 9:01pm; sunrise tomorrow: 5:34am. Extended Outlook: The parent upper-level low pressure center will slowly drift inland, across the interior of southern British Columbia, Tuesday and Wednesday. Weak disturbances, rotation around it, will swing onshore across western Washington and western Oregon. That will turn the flow aloft southwesterly and maintain strong onshore flow at the surface. Thick marine low clouds will be persistent again with a chance of sprinkles or light showers. Temperatures will remain well below normal. The upper-level trough is forecast to stall and weaken over the region Thursday and Friday, with continued southwesterly flow aloft. Onshore flow at the surface will maintain night and morning marine low clouds across the Willamette Valley with increasing amounts of afternoon clearing leading to slowly warming temperatures. The trough is then forecast to get kicked inland over the weekend, which will maintain the threat of a shower through Sunday. Tomorrow (07 Jul): Mostly Cloudy. Chance of Sprinkles or Light Showers. 52/68 Wed (08 Jul): Mostly Cloudy. Chance of Sprinkles or Light Showers. 52/68 Thu (09 Jul): Mostly Cloudy. Chance of Sprinkles. Partial Afternoon Clearing. 52/72 Fri (10 Jul): AM Clouds. Partly Sunny in the Afternoon. Slight Chance of a Shower. 53/78 Sat (11 Jul): AM Clouds. Partly Sunny in the Afternoon. Slight Chance of a Shower. 54/79 Sun (12 Jul): Mostly Cloudy. Slight Chance of a Shower. 55/78 Mon (13 Jul): Becoming Mostly Sunny and Warmer. 53/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Jul 6 12:03:54 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 06 Jul 2009 14:03:54 -0500 Subject: [willamette-fcst] Forecast - Monday, July 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. NOON UPDATE...Updated Burn Advisory to Include Stack Burning... Issued: Monday, July 6th, 2009 at 12:00pm. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 11:00am until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed from 11:00am until 8:00pm. Weather Discussion: A dry cold front shifted the windflow pattern to onshore Sunday and began a cooling trend across western Oregon. Willamette Valley highs Sunday topped out in the upper 70s and low 80s...about 10-15 degrees cooler than they were Thursday through Saturday. A significant push of cooler marine air surged inland Sunday night. Low clouds blanketed the western valleys this morning and should be persistent today, especially in the northern Willamette Valley. High temperatures will be another 10 degrees cooler today, with highs struggling to reach 70. The initial cold front was strong enough to bring some shower and thundershower activity to Washington state, which extending southward into northeastern Oregon Sunday evening. Pendleton and Meacham both picked up about one-tenth of an inch of rain and thunderstorms extended as far south and east as Baker City, with CoCoRaHs reports showing close to a tenth of an inch of rain falling is sections of northern Baker County. West of the Cascades, spots along the northern and central coast picked up a couple hundredths of an inch of rain overnight with some sprinkles making it into the northwestern interior. The late-morning ODA surface analysis showed the cold front advancing across central Idaho, with cooler onshore flow spreading over of all of Oregon. Onshore pressure gradients were strongest east of the Cascades, with 25-35 mph westerly wind gusts extending from Hermiston and Pendleton southweard to Rome. Southelry winds in the Willamette Valley were beginning to turn southwesterly, in the 5-15 mph range, with gusts to around 20 mph in the north. Infrared satellite imagery showed the main cloud-band, associated with the surface cold front, had pushed mostly east of Washington and northeastern Oregon. More middle and clouds were circulating around the parent low-pressure center, over Vancouver Island, into northwestern Washington. Visible satellite imagery showed extensive low clouds covering all of western Washington...extending southward across western Oregon through Linn County. The low clouds were beginning to break up over Lane County, where the onshore flow was not as strong. Skies were sunny over southwestern Oregon and east of the Cascades, except for a few clouds near the Idaho border. Midday temperatures were generally in the mid 50s across the coast and low to mid 60s in the western valleys. Readings east of the Cascades ranged from the mid 60s, in central Oregon, to the low 80s in Ontario, near the Idaho border. Doppler radar showed a few showers developing in north-central Washington and possible sprinkles , out ot the marine deck, over western Washington and northwestern Oregon. The showers and thunderstorms from the initial cold front had pushed eastward to over Idaho and Montana. The Salem sounding this morning showed almost 20-25 degrees of cooling aloft, up to about 7000 feet. The air mass was also saturated between 3000 and 6500 feet (the thickness of the morning marine clouds). The upper-level trough responsible for the drastic change in the weather will slowly drift eastward today, into southern British Columbia, with continued westerly flow aloft over Washington and Oregon. Strong onshore flow will help marine clouds to be quite persistent over the northern Willamette Valley today. The south valley will see a fair amount of clearing this afternoon. High temperatures may not climb out the 60s across much of the north valley this afternoon. However, more clearing in the south valley should help temperatures there climb into the low 70s. Surface Winds: S 5-15 G20...becoming W 5-15 later this afternoon. Transport Winds: SW 12...becoming W 10 later this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 54. High Temperature: Salem\'s high temperature today will be near 68. Humidities: Minimum relative humidity will be near 50%. Sunrise/Sunset: Salem sunset tonight: 9:01pm; sunrise tomorrow: 5:34am. Extended Outlook: The upper-level low pressure center will slowly drift across the interior of southern British Columbia Tuesday and Wednesday. Weak disturbances, rotating around it, will swing onshore across western Washington and western Oregon. That will turn the flow aloft southwesterly and maintain strong onshore flow at the surface. Thick marine low clouds will be persistent again with a chance of sprinkles or light showers. Temperatures will remain well below normal. The upper-level trough is forecast to stall and weaken over the region Thursday and Friday, with continued southwesterly flow aloft. Onshore flow at the surface will maintain night and morning marine low clouds across the Willamette Valley with increasing amounts of afternoon clearing leading to slowly warming temperatures. The trough is forecast to move inland this weekend, with the flow aloft turning northwesterly, and drying out, early next week. Tomorrow (07 Jul): Mostly Cloudy. Chance of Sprinkles or Light Showers. 52/68 Wed (08 Jul): Mostly Cloudy. Chance of Sprinkles or Light Showers. 52/68 Thu (09 Jul): Mostly Cloudy. Chance of Sprinkles or Light Showers. 52/72 Fri (10 Jul): AM Clouds. Partly Sunny in the Afternoon. Slight Chance of a Shower. 53/78 Sat (11 Jul): AM Clouds. Partly Sunny in the Afternoon. Slight Chance of a Shower. 54/79 Sun (12 Jul): Mostly Cloudy. Slight Chance of a Shower. 55/78 Mon (13 Jul): Becoming Mostly Sunny and Warmer. 53/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Jul 6 12:13:31 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 06 Jul 2009 14:13:31 -0500 Subject: [willamette-fcst] Forecast - Monday, July 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. NOON UPDATE...Updated Burn Advisory to Include Stack Burning... Issued: Monday, July 6th, 2009 at 12:00pm. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 11:00am until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed from 11:00am until 8:00pm. Weather Discussion: A dry cold front shifted the windflow pattern to onshore Sunday and began a cooling trend across western Oregon. Willamette Valley highs Sunday topped out in the upper 70s and low 80s...about 10-15 degrees cooler than they were Thursday through Saturday. A significant push of cooler marine air surged inland Sunday night. Low clouds blanketed the western valleys this morning and should be persistent today, especially in the northern Willamette Valley. High temperatures will be another 10 degrees cooler today, with highs struggling to reach 70. The initial cold front was strong enough to bring some shower and thundershower activity to Washington state, which extending southward into northeastern Oregon Sunday evening. Pendleton and Meacham both picked up about one-tenth of an inch of rain and thunderstorms extended as far south and east as Baker City, with CoCoRaHs reports showing close to a tenth of an inch of rain falling is sections of northern Baker County. West of the Cascades, spots along the northern and central coast picked up a couple hundredths of an inch of rain overnight with some sprinkles making it into the northwestern interior. The late-morning ODA surface analysis showed the cold front advancing across central Idaho, with cooler onshore flow spreading over of all of Oregon. Onshore pressure gradients were strongest east of the Cascades, with 25-35 mph westerly wind gusts extending from Hermiston and Pendleton southweard to Rome. Southelry winds in the Willamette Valley were beginning to turn southwesterly, in the 5-15 mph range, with gusts to around 20 mph in the north. Infrared satellite imagery showed the main cloud-band, associated with the surface cold front, had pushed mostly east of Washington and northeastern Oregon. More middle and clouds were circulating around the parent low-pressure center, over Vancouver Island, into northwestern Washington. Visible satellite imagery showed extensive low clouds covering all of western Washington...extending southward across western Oregon through Linn County. The low clouds were beginning to break up over Lane County, where the onshore flow was not as strong. Skies were sunny over southwestern Oregon and east of the Cascades, except for a few clouds near the Idaho border. Midday temperatures were generally in the mid 50s across the coast and low to mid 60s in the western valleys. Readings east of the Cascades ranged from the mid 60s, in central Oregon, to the low 80s in Ontario, near the Idaho border. Doppler radar showed a few showers developing in north-central Washington and possible sprinkles , out ot the marine deck, over western Washington and northwestern Oregon. The showers and thunderstorms from the initial cold front had pushed eastward to over Idaho and Montana. The Salem sounding this morning showed almost 20-25 degrees of cooling aloft, up to about 7000 feet. The air mass was also saturated between 3000 and 6500 feet (the thickness of the morning marine clouds). The upper-level trough responsible for the drastic change in the weather will slowly drift eastward today, into southern British Columbia, with continued westerly flow aloft over Washington and Oregon. Strong onshore flow will help marine clouds to be quite persistent over the northern Willamette Valley today. The south valley will see a fair amount of clearing this afternoon. High temperatures may not climb out the 60s across much of the north valley this afternoon. However, more clearing in the south valley should help temperatures there climb into the low 70s. Surface Winds: S 5-15 G20...becoming W 5-15 later this afternoon. Transport Winds: SW 12...becoming W 10 later this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 54. High Temperature: Salem\'s high temperature today will be near 68. Humidities: Minimum relative humidity will be near 50%. Sunrise/Sunset: Salem sunset tonight: 9:01pm; sunrise tomorrow: 5:34am. Extended Outlook: The upper-level low pressure center will slowly drift across the interior of southern British Columbia Tuesday and Wednesday. Weak disturbances, rotating around it, will swing onshore across western Washington and western Oregon. That will turn the flow aloft southwesterly and maintain strong onshore flow at the surface. Thick marine low clouds will be persistent again with a chance of sprinkles or light showers. Temperatures will remain well below normal. The upper-level trough is forecast to stall and weaken over the region Thursday and Friday, with continued southwesterly flow aloft. Onshore flow at the surface will maintain night and morning marine low clouds across the Willamette Valley with increasing amounts of afternoon clearing leading to slowly warming temperatures. The trough is forecast to move inland this weekend, with the flow aloft turning northwesterly, and drying out, early next week. Tomorrow (07 Jul): Mostly Cloudy. Chance of Sprinkles or Light Showers. 52/68 Wed (08 Jul): Mostly Cloudy. Chance of Sprinkles or Light Showers. 52/68 Thu (09 Jul): Mostly Cloudy. Chance of Sprinkles or Light Showers. 52/72 Fri (10 Jul): AM Clouds. Partly Sunny in the Afternoon. Slight Chance of a Shower. 53/78 Sat (11 Jul): AM Clouds. Partly Sunny in the Afternoon. Slight Chance of a Shower. 54/79 Sun (12 Jul): Mostly Cloudy. Slight Chance of a Shower. 55/78 Mon (13 Jul): Becoming Mostly Sunny and Warmer. 53/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Jul 7 09:02:22 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 07 Jul 2009 11:02:22 -0500 Subject: [willamette-fcst] Forecast - Tuesday, July 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: Tuesday, July 7th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 11:00am until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed from 11:00am until 8:00pm. Weather Discussion: An upper-level trough remains over the region this morning. Onshore flow is continuing at the surface with visible satellite imagery showing marine low clouds blanketing western Washington and most of western Oregon...extending southward into Douglas County. Pilot reports this morning show cloud-tops between 3600 and 4200 feet, which is about 2000 feet lower than Monday morning and favors more breaks this afternoon. Some breaks in the low clouds were already visible off the coastline, where a weak upper-level disturbance is helping to create some instability. With cooler marine air spilling across the entire state, temperautures this morning were much cooler east of the Cascades. Mid-morning readings were in the 50s and 60s. Western Oregon temperatures were mostly in the 50s. Onshore gradients were stronger east of the Cascades than west of the Cascades but weaker than they were Monday morning. As a weak upper-level disturbance moves moves onshore, it will aid in the break-up of the low clouds over the valley this afternoon. That should help temperatures climb into the low 70s, but cool air aloft will prevent more warming than that. The incoming weak upper-level disturbance is forecast to rotate another surge of cool marine air onshore late this afternoon and evening. It may be accompanied by a light shower. Cooling aloft and forecast westerly transport winds may create favorable ventilation conditions for burning this afternoon, for available fields. However, the current pressure gradient-stacking would need to be reversed by the combination of daytime heating and the approaching weather system. That may not happen and will be monitored this afternoon. Surface Winds: WSW 3-8 this morning, W 5-15 this afternoon. Transport Winds: WSW 5 this morning, WNW 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 71. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 44%. Sunrise/Sunset: Salem sunset tonight: 9:00pm; sunrise tomorrow: 5:34am. Extended Outlook: The forecast weather pattern maintains enough of a westerly component, through next week, for potential burning opportunities at times... An upper-level trough of low pressure will remain over the Pacific Northwest Wednesday and Thursday with weak disturbances rotating across the region. That will maintain onshore flow across western Washington and western Oregon with considerable amounts of clouds and below normal temperatures. There will also be at least a slight chance of sprinkles or light showers at times...especially north. The trough is forecast to weaken and shift slightly offshore by Friday. That would put Oregon under a slightly warmer southwesterly flow aloft. Onshore flow at the surface would likely still be strong enough to keep considerable clouds across western Oregon with temperatures only warming a little closer to normal. The trough is still forecast to move inland this weekend, which would increase the onshore flow, cool temperatures a few degrees, and heighten the threat of light showers. A transitory ridge is forecast to bring a drier northwesterly flow on Monday with more sunshine warming temperatures to around normal. Another weak trough is forecast to turn to flow southwesterly again on Tuesday with increasing onshore flow. West-southwesterly flow aloft is forecast for the middle of next week, which would keep temperatures slightly below normal. Tomorrow (08 Jul): Mostly Cloudy. Chance of Sprinkles or Light Showers. 52/68 Thu (09 Jul): Mostly Cloudy. Slight Chance of Sprinkles or Light Showers. 52/73 Fri (10 Jul): Partly Sunny and a Little Warmer. 53/78 Sat (11 Jul): Partly Sunny. Increasing Onshore Flow Late. 54/79 Sun (12 Jul): Mostly Cloudy and Cooler. Chance of a Light Showers North. 53/73 Mon (13 Jul): Becoming Mostly Sunny and Warmer. 53/82 Tue (14 Jul): Partly Cloudy. Increasing Onshore Flow Late. 54/81 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Jul 8 09:01:51 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 08 Jul 2009 11:01:51 -0500 Subject: [willamette-fcst] Forecast - Wednesday, July 8th, 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, July 8th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 11:00am until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: An upper-level low-pressure area is parked over southern British Columbia with a trough extending south over the Pacific Northwest. Onshore flow increased overnight across western Oregon, in response to a weak upper-level disturbance rotation across the state. That system was strong enough to bring some light showers to the north coast and sprinkles into the interior of western Oregon overnght. The Salem sounding this morning showed the cool low-level marine layer was about 2000 feet thicker than on Tuesday morning. Morning pilot reports confirm that the top of the low cloud deck over the Willamette Valley extended up to about 6000 feet. Visible satellite imagery showed solid coverage of low clouds over western Washington and most of western Oregon...extending southward over most of Douglas County and to the California border along tha near the coastline. Unlike yesterday morning, the solid deck of low clouds extended well offshore. Dopper radar was also showing some light showers over northwetern Oregon, and Astoria picked up a few hundredths of an inch of rain this morning. Skies were mostly sunny east of the Cascades this morning. Mid-morning temperatures were mostly in the 50s statewide. The mid-morning ODA surface analysis showed southerly gradients across the Willamette Valley with an onshore push entending eastward to the Idhao border. Current gradient stacking is not conducive to goo ventilation for burning, and it is unlikely that there will be enough warming west of the Cascades to reverse that pattern this afternoon. With a later break-up of the low clouds today, and the ongoing threat of a light shower, highs will be lucky to reach the low 70s again in the Willamette Valley. Surface Winds: S 5-10 this morning, WSW 5-15 this afternoon. Transport Winds: SW 10 this morning, WSW 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 70. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 46%. Sunrise/Sunset: Salem sunset tonight: 9:00pm; sunrise tomorrow: 5:35am. Extended Outlook: The forecast weather pattern maintains enough of a westerly component, through next week, for potential burning opportunities at times... An upper-level trough of low pressure will drift offshore Thursday and Friday with weak disturbances rotating across the region. That will weaken the onshore flow across western Washington and western Oregon with some warming and drying of the air mass. There will continue to be at least a slight chance of sprinkles or light showers at times...especially north. The trough is still forecast to move inland this weekend, which would increase the threat of light showers and bring in a new surge of cooler marine air by Sunday. A transitory ridge is forecast to bring a drier northwesterly flow on Monday with more sunshine warming temperatures to around normal. Another weak trough is forecast to turn to flow southwesterly again on Tuesday with increasing west-southwesterly flow aloft keeping temperatures from climbing much above normal through the middle of next week. Tomorrow (09 Jul): Mostly Cloudy. Slight Chance of Sprinkles or Light Showers. 52/74 Fri (10 Jul): Partly Sunny and a Little Warmer. 53/78 Sat (11 Jul): Partly Sunny. Increasing Onshore Flow and Chance of Showers Late. 54/78 Sun (12 Jul): Mostly Cloudy and Cooler. Chance of Showers...Mainly North. 53/73 Mon (13 Jul): Becoming Mostly Sunny and Warmer. 53/82 Tue (14 Jul): Partly Cloudy. Increasing Onshore Flow Late. 54/82 Wed (15 Jul): AM Clouds...Partly Sunny. 53/80 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Jul 9 09:02:56 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 09 Jul 2009 11:02:56 -0500 Subject: [willamette-fcst] Forecast - Thursday, July 9th, 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, July 9th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 11:00am until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Visible satellite imagery showed extensive low clouds blanketing western Washington and most of western Oregon this morning. There has also been some areas of drizzle reported along the coastline. Mid-morning temperatures were mostly in the upper 50s along the coast and in the Willamette Valley. Winds were light and variable. The upper-level trough that has been responsible for the cool and cloudy weather the past couple of days is weakening and has moved westward to off the Washington Coast. That is decreasing the low-level onshore flow, so expect the extensive morning low clouds over western Oregon to give way to some sunshine during the afternoon, with high temperatures warming into the mid 70s (valley highs only reached about 70 on Wednesday, and normal highs for this time of year are around 80 degrees). Infrared satellite imagery showed only minimal mid and high level cloudiness over western Washington and western Oregon this morning, but that was a well organized band of clouds, in association with the jet stream, stretching from south-central to northeastern Oregon. Doppler radar was showing some shower activity developing in Lake County, and further shower and thundershower developement is likely, from the Cascades eastward across central and eastern Oregon today. There should be enough of a westerly component to the upper-level winds to keep thundershowers east of the Willamette Valley. The Salem sounding this morning showed warming aloft, in response to the weakening upper-level trough offsore. Wind speeds had also decreased significantly in the mid-levels of the atmosphere. The mid-morning ODA surface analysis showed very weak gradients over western Oregon with onshore flow continuing east of the Cascades. Current gradient stacking is not conducive to good ventilation for burning. Daytime heating may help reverse the gradient-stacking pattern, but transport winds may become too northerly for burning this afternoon. Surface Winds: NW 0-6 this morning, NW 5-10 this afternoon. Transport Winds: NW 4 this morning, NW 6 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5000 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 76. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 42%. Sunrise/Sunset: Salem sunset tonight: 8:59pm; sunrise tomorrow: 5:36am. Extended Outlook: The offshore upper-level trough of low pressure is forecast to continue weakening and drifing southwestward Friday and Satruday. It is forecast to be well off the southern Oregon Coast by Friday evening. That will further weaken the onshore flow and turn the flow aloft more southerly over western Oregon. There is a chance that afternoon showers and thunderstorms could develop over the Cascades and drift northwestward to over the Willamette Valley..introducing a chance of afternoon showers of thundershowers...even over the Willamette Valley. Transport winds are forecast to become northerly, which is not conducive to good ventilation for burning. The trough is forecast to move inland Sunday, which will likely bring some showers and possible thundershowers to much of western Oregon, along with increasing onshore flow and cooler temperatures. A transitory ridge is forecast to bring a drier northwesterly flow on Monday and move directly over the regin Tuesday. Increasing west-southwesterly flow aloft will cool temperatures around the middle of next week. Tomorrow (10 Jul): Partly Sunny and Warmer. Slight Chance of PM Showers/T-Storms. 53/82 Sat (11 Jul): Partly Sunny and Warmer. Slight Chance of PM Showers/T-Storms. 54/85 Sun (12 Jul): Mostly Cloudy and Cooler. Good Chance of Showers/T-Storms. 55/75 Mon (13 Jul): Becoming Mostly Sunny and Warmer. 54/80 Tue (14 Jul): Mostly Sunny and Warm. 54/84 Wed (15 Jul): Partly Cloudy and Cooler. 53/80 Thu (16 Jul): Partly Cloudy. 53/81 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Jul 10 08:59:50 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 10 Jul 2009 10:59:50 -0500 Subject: [willamette-fcst] Forecast - Friday, July 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: Friday, July 10th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 1:00pm until 7:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Mid-morning satellite imagery showed mostly clear skies east of the cascades, but mostly cloudy skies across western Oregon, due to a moist southerly flow aloft around an upper-level low-pressure area, centered about 200 miles off the southern Oregon Coast. Doppler radar was showing some light shower activity, moving to the north-northwest, along the central coast range and over the southern Cascades. With the low-pressure system offshore remaining nearly stationary offshore today, it will continue to feed mid and high-level moisture over western Oregon. Daytime heating will destabilize the atmosphere and increase shower development this afternoon...mainly over the mountains. Some showers could drift over the Willamette Valley, and there is even a slight chance of a thunderstorm. With afternoon clearing, Willamette Valley temperatures climbed into the mid 70s Thursday. The Salem sounding this morning showed warming aloft, since Thursday, so partly sunny skies should help temperatures climb into the low 80s this afternoon. The ODA surface analysis confirmed a shut-off of the onshore flow across the state with northerly pressure gradients. Transport winds are forecast to remain northerly today. Surface Winds: N 5-12 this morning, N 7-15 this afternoon. Transport Winds: N 10 this morning, N 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 54. 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: 8:59pm; sunrise tomorrow: 5:37am. Extended Outlook: The upper-level low-pressure center is forecast to remain off the southern Oregon Coast Saturday, with continued southerly fow aloft over western Oregon. That will keep temperatures warm statewide, with a continued feed of mid and high-level moisture over the region. Afternoon and evening showers and thunderstorms should develop, mainly over the Cascades, with the chance of showers and thundershowers increasing Saturday night across the Willamette Valley. The trough is forecast to move inland Sunday, with showers likely acrsoss most of western Oregon. There may be enough instability remaining in the mid and upper levels of the atmosphere for thunderstorms through early Sunday, before the cooler onshore flow deepens and stabilizes the mid-levels of the air mass. A transitory ridge is forecast to bring a drier northwesterly flow by Monday afternoon with the ridge moving over Oregon Tuesday. Increasing west-southwesterly flow aloft will enhance the onshore flow and cool temperatures back to near or slightly below normal Wednesday through Friday. Transport winds are forecast to take on more of a westerly component, which could create burning opportunities. Sat (11 Jul): Partly Sunny and Warm. Chance of Showers/T-Storms...Increasing Late. 57/84 Sun (12 Jul): Mostly Cloudy and Cooler. Good Chance of Showers/T-Storms. 55/74 Mon (13 Jul): Clearing Skies by Afternoon. Warmer. 54/79 Tue (14 Jul): Mostly Sunny and Warm. 51/84 Wed (15 Jul): Partly Cloudy with Onshore Flow Developing. 53/80 Thu (16 Jul): Partly Cloudy. 54/81 Fri (17 Jul): Partly Cloudy. 54/81 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Jul 13 08:57:42 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 13 Jul 2009 10:57:42 -0500 Subject: [willamette-fcst] Forecast - Monday, July 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: Monday, July 13th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 7:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: An impressively moist upper-level low pressure system moved onto the central Oregon Coast Sunday morning, across the central Willamette Valley Sunday afternoon and evening. It continued to track northeastward overnight and was centered over northeastern Oregon this morning. Significant rainfall accompanied this system, with numerous showers and thundershowers dropping between one-quarter and three-quarters of an inch across the Willamette Valley. Doppler radar showed the shower activity had mostly moved mostly east of the Cascades by mid-morning, with the greatest concentration near and north of the low-pressure center, over eastern Washington, northern Idaho, western Montana, and extreme northeastern Oregon. Satellite imagery showed a blanket of low clouds continuing to cover most of western Oregon, from the coast to the creast of the Cascades. The only areas in Oregon seeing much sunshine were the extreme southwestern and south-central sections of the state. The upper-level trough is forecast to continue moving northeastward today, to over cenral Montana by this evening. The flow aloft over western Oregon had already turned northwesterly by 5am, when the Salem sounding was taken. The ODA surface analysis showed high pressure building into the central Oregon Coast, with southerly winds in the Willamette Valley and onshore flow extending eastward into Idaho. Onshore gradients were stronger over eastern Oregon than across western Oregon...indicating that the air aloft over the Willamette Valley was beginning to sink and warm. As an upper-level ridge moves onshore this afternoon, sinking northwesterly flow flow aloft should gradually clear the skies over western Oregon with high temperatures recoving into the mid 70s (Highs Sunday only reached the mid 60s). Southerly surface winds should veer to northwesterly by late this afternoon. More clearing tonight will combine with the cool air mass over the region to locally drop Willamette Valley temperatures into the 40s. Surface Winds: S 5-10 this morning, NW 5-12 this afternoon. Transport Winds: SW 10 this morning, W 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4300 feet. Ventilation index 43. High Temperature: Salem\'s high temperature today will be near 75. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 8:57pm; sunrise tomorrow: 5:39am. Extended Outlook: The upper-level ridge will build close to the coastline Tuesday, with a dry northwesterly flow aloft and increasing northerly winds at the surface. That will aid in the drying of damp fields across the Willamette Valley. Patchy morning clouds should quickly give way to sunny skies with high temperatures recovering to near-normal. In a change from what was advertised last week by the long-range computer models, the upper-level ridge is now forecast to shift only slightly eastward Wednesday and Thursday, with very weak southwesterly flow aloft developing over western Oregon. That pattern would allow temperatures to continue warming slightly, as surface winds stay northerly. Friday and Saturday, southwesterly flow aloft is forecast to increase enough to shift the surface thermal trough into eastern Oregon. That would increase the onshore flow into western Oregon and begin cooling temperatures. It is too far out to tell when or if this pattern change may create a burning opportunity, but that is at least possible, late this week. In the very long-range, a little stronger system is forecast bring increased onshore flow and more cooling early next week. Tue (14 Jul): Ppatchy AM Clouds...Sunny and Warmer. Northerly Winds. 49/84 Wed (15 Jul): Mostly Sunny and Warmer. 53/88 Thu (16 Jul): Mostly Sunny and Warm. 54/89 Fri (17 Jul): Mostly Sunny and Warm. 54/87 Sat (18 Jul): Partly Cloudy. Not Quite as Warm. 54/82 Sun (19 Jul): Partly Cloudy. 54/82 Mon (20 Jul): Partly Cloudy. 54/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Jul 14 09:00:48 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 14 Jul 2009 11:00:48 -0500 Subject: [willamette-fcst] Forecast - Tuesday, July 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: Tuesday, July 14th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 1:00pm until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Clearing skies overnight allowed for much cooler temperatures statewide. Readings locally dropped into the 30s across eastern Oregon this morning, with sections of the Willamette Valley dipping into the 40s. Meacham and Burns both recorded the low in the state of 35 degrees and Baker City dropped to 38 degrees. On the west side of the Cascades, Salem, Corvallis, and Eugene all fell to just 48 degrees this morning, before low clouds and areas of fog reformed. Visible satellite imagery showed low clouds blanketing western Washington again this morning and extending south over most of the Willamette Valley. Unlike yesterday, however, skies were already beginning to clear along the Oregon Coast, with onshore winds turning northerly. Skies were mostly clear over southwestern Oregon and over all of central and eastern Oregon. The ODA surface analysis showed a trough of low pressure extending from east-central Washington into north-central Oregon with high pressure strongly building into western Washington and northwestern Oregon. A thermal trough was beginning to build northward, from northern California, into extreme southwestern Oregon. Pressure gradients were still onshore across western Washington and extreme northwestern Oregon but turned northerly across the southern half of western Oregon...including the central and southern Oregon Coast and southern Willamette Valley. An upper-level ridge is building just offshore with the Salem sounding this morning showing considerable warming and a much drier northwesterly flow aloft. The ridge is forecast to remain offshore today, which will maintain the dry northwesterly flow aloft. Northerly surface gradients will increase this afternoon across the western Oregon, as a thermal trough builds northward into extreme southwestern Oregon. Areas of morning clouds should give way to sunny skies over western this afternoon with temperatures recovering to near-normal (low to mid 80s), after being below normal for 7 of the past 8 days. In addition, relative humidities will drop to near or slightly below 30% by late this afternoon, which will aid in the drying of damp fields. Surface Winds: N 5-12 this morning, N 7-15 G20 south this afternoon. Transport Winds: NNE 10 this morning, NNE 14 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3700 feet. Ventilation index 52. High Temperature: Salem\'s high temperature today will be near 84. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 28%. Sunrise/Sunset: Salem sunset tonight: 8:56pm; sunrise tomorrow: 5:40am. Extended Outlook: The upper-level ridge is forecast to slowly shift eastward to over eastern Oregon Wednesday and to over western Idaho Thursday, with slowly increasing southwesterly flow aloft over western Oregon. That pattern would allow temperatures to continue warming over all of Oregon, with the possible exception of the immediate coastline, where there would be some increase in onshore flow. Sunny skies should continue, along with drying northerly winds. A broad upper-level ridge is forcast to shift eastward, to over western Montana, by Friday with the associated surface thermal trough finally sliding east of the Cascades. That would bring increasing onshore flow into western Oregon Friday afternoon and at least keep temperatures from warming any further. That may also create a burning opportunity, but that is still way too far out to call at this time. Onshore flow will increase Saturday, as a weak upper-level trough moves onshore into southwest British Columbia. No rain is forecast from this system, except for possible drizzle along the coast early Sunday, but temperatures should cool back to near-normal Saturday and slightly below normal Sunday. Another weak trough is forecast to move by to our north Monday...maintaining onshore flow. Tomorrow (15 Jul): Sunny and Warmer. 51/90 Thu (16 Jul): Sunny and Warm. 55/91 Fri (17 Jul): Mostly Sunny and Warm. 56/88 Sat (18 Jul): Partly Cloudy. Near-Normal Temperatures. 54/80 Sun (19 Jul): Partly Cloudy. 55/78 Mon (20 Jul): Partly Cloudy. 54/79 Tue (21 Jul): Mostly Sunny and Warmer. 52/85 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Jul 15 08:59:33 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 15 Jul 2009 10:59:33 -0500 Subject: [willamette-fcst] Forecast - Wednesday, July 15th, 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 may be met late this afternoon due to low humidities and wind... Issued: Wednesday, July 15th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 1:00pm until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Clear skies overnight allowed temperatures to locally drop into the 40s again across the Willamette Valley by early this morning. Eugene dipped to 47 degrees and Hillsboro hit 48. Most of the valley and the coast stayed in the 50s. Portland and Medford were the warm spots in the state this morning, both recording minimums of 59. Meacham, in northeastern Oregon, was the cool spot, with a low of 36 degrees. Visible satellite imagery showed a deck of marine low clouds banked up against the length of the Washington and Oregon coastlines. Only a few low clouds had penetrated some of the coastal gaps and advanced into the western valleys. Skies were sunny over the reaminder of Washington, Oregon, and Idaho this morning. Fog and low clouds were holding mid-morning temperatures along the Oregon coastal strip in the 50s, but sunshine had already warmed inland temperatures, on both sides of the Cascades, into the 60s. A broad and fairly flat upper-level ridge will move directly over Oregon today. The Salem sounding this morning showed more warming above 3000 feet with weak westerly flow aloft and north-northeasterly flow near the surface. The mid-morning ODA surface analysis showed a weak trough extending from south-central Washington to southwestern Oregon with weak pressure gradients across Oregon. Winds were generally light and variable across the state. Sunshine will prevail over the interior of western Oregon today. Northerly winds will increase across the Willamette Valley this afternoon, in response to a building thermal trough into southwestern Oregon. Warmer air aloft and continued drying of the air mass will help Willamette Valley high temperatures climb into the upper 80s this afternoon, after peaking out near 80 on Tuesday. Coastal morning fog and low clouds should clear over the northern and central beaches this afternoon, but the southern coast may stay cloudy all day. Sunny skies will help temperatures east of the Cascades climb into the 80s and 90s. Surface Winds: N 3-10 this morning, N 5-15 G20 south this afternoon. Transport Winds: NNE 10 this morning, N 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3300 feet. Ventilation index 33. High Temperature: Salem\'s high temperature today will be near 89. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 24%. Sunrise/Sunset: Salem sunset tonight: 8:55pm; sunrise tomorrow: 5:41am. Extended Outlook: The upper-level ridge is forecast to slowly shift eastward to near the Oregon/Idaho border Thursday, with increasing southwesterly flow aloft over western Oregon. That would allow temperatures to continue warming over all of Oregon, with the exception of the immediate coastline, where increasing onshore flow would keep maintain lots of marine low clouds and cooler temperaturs. Sunny skies should continue inland with transport winds remaining northerly over the Willamette Valley. The upper-level ridge is forecast to shift eastward, to over Idaho and western Montana, by Friday with the associated broad surface thermal trough finally sliding east of the Cascades. That may bring enough onshore flow into western Oregon Friday afternoon to turn transport winds from northerly to northwesterly. That could create a burning opportunity...especially for the north valley, but the region may also be flirting with State Fire Marshal conditions due to high temperatures and low humidities. The upper-level ridge will shift further east over the weekend, with increasing onshore flow at the surface eventually spreading across all of Oregon. Increasing south-southwesterly flow aloft will likely spread enough mid and high-level moisture into central and eastern Oregon to trigger some afternoon and evening thunderstorms. Marine low clouds should penetrate into the western valleys by Sunday morning for significant cooling. Precipitation west of the Cascades appears as if it will be limited to some possible drizzle along the coast...mainly in the late-night and early morning periods. A weak upper-level trough is forecast to move by to our north Monday, with onshore flow beginning to turn more northerly in the afternoon. An upper-level ridge is forecast to begin building back over the region on Tuesday for a return to sunny and warmer conditions. There is some indication that this ridge may be rather persistent and possibly quite strong by the end of next week. That would bring hot weather to western Oregon, but that is still too far out to be certain of at this time. Tomorrow (16 Jul): Sunny and Warm. North Winds. 55/91 Fri (17 Jul): Mostly Sunny and Very Warm. Increasing Onshore Flow Late. 56/93 Sat (18 Jul): Mostly Sunny but Not As Warm. Increasing Onshore Flow. 54/85 Sun (19 Jul): Morning Clouds. Partly Sunny in the Afternoon. Cooler. 55/78 Mon (20 Jul): Morning Clouds. Mostly Sunny in the Afternoon. 52/80 Tue (21 Jul): Mostly Sunny and Warmer. 52/85 Wed (22 Jul): Sunny and Warm. 55/87 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Jul 16 08:58:39 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 16 Jul 2009 10:58:39 -0500 Subject: [willamette-fcst] Forecast - Thursday, July 16th, 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 may be met this afternoon due to low humidities and wind... Issued: Thursday, July 16th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 1:00pm until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: After a sunny and much warmer day, on Wednesday, with Willamette Valley highs climbing mostly into the upper 80s, clear skies overnight allowed temperatures to drop mostly into the 50s. Hillsboro was the coolest spot with a minimum of 51 degrees. Corvallis and Eugene both dipped to 54. As usual, Portland was the warm spot...staying in the low 60s. The coast was cloudy and foggy this morning with temperatures in the upper 40s and low 50s. Mewanwhile, skies were mostly clear east of the Cascades, with minimums ranging from 40 degrees at Meacham to 60 at John Day. Visible satellite imagery showed low clouds banked up along the entire length of the Washington, Oregon, and California coastlines, with some minor penetration into the coastal mountain gaps along the southern Oregon Coast, south of Florence. Elsewhere across the Pacific Northwest, skies were mostly clear, with only some high clouds over extreme eastern Oregon and Idaho. The ODA surface analysis showed a broad thermal trough covering most of Washington and Oregon...resulting in weak northerly pressure gradients over the interior and onshore gradients along the coastal strip. An upper-level ridge of high pressure will remain over Oregon today...shifting slightly east to near the Oregon/Idaho border by late this afternoon. Weak southwesterly flow aloft will maintain onshore flow along the coast, where temperatures will stay cool with areas of afternoon clearing...mainly north. Skies will be sunny, with slightly warmer temperatures, east of the coast range today. High today will range from the 60s on the central and south coast, where low clouds will be the most persistent, to the low 70s on the north coast. Willamette Valley highs today should climb into the low 90s, after peaking mostly in the upper 80s Wednesday afternoon. Surface and transport winds are forecast to remain northerly today, which is not conducive to good ventilation for open burning in the Willamette Valley. Surface Winds: N 3-8 this morning, N 5-15 this afternoon. Transport Winds: NNE 8 this morning, N 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 28. 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: 8:55pm; sunrise tomorrow: 5:42am. Extended Outlook: The upper-level ridge is forecast to shift eastward, to over Idaho and western Montana, on Friday with the center of the associated broad surface thermal trough moving into central Oregon. Temperatures will likely warm a couple of more degrees across the interior of western Oregon, with transport winds forcast to stay northerly...limiting any onshore flow. That makes a burning opportunity unlikely on Friday. There is a slight chance that transport winds could shift from northerly to northwesterly late in the day, but that is looking less likely with each run of the computer models. The region may also be flirting with State Fire Marshal conditions, again, due to high temperatures and low humidities. The upper-level ridge will shift further east, to over eastern Idaho and western Montana, on Saturday. Increasing southwesterly flow aloft over Oregon will drive some mid and high-level miosture into central and eastern Oregon for an increasing threat of afternoon and evening thunderstorms. The surface thermal trough, and warmest temperatures, is forecast to shift into eastern Oregon, with increasing onshore flow across the interior of western Oregon. That should cool temperatures back into the 80s across the Willamette Valley. A weak upper-level trough is forecast to finally move onshore, across southern British Columbia, Sunday afternoon...pushing the surface thermal trough into Idaho and ushering a significant surge of cooler ocean air across Oregon. Willamette Valley highs should cool to near 80 degrees (slightly below normal) with some marine low clouds possibly penetrating into the western valleys in the morning. Precipitation west of the Cascades appears as if it will be limited to a chance of drizzle along the coast. The thundershower threat, east of the Cascades, will get pushed closer to the Idaho border, as cooler and more stable air surges into central Oregon. An upper-level ridge is forecast to begin building back over the region Monday, for a return to sunny and warmer conditions. A weak system may brush the region with some high clouds late Tuesday and Wednesday, with an increase in onshore flow keeping temperatures near normal. Tomorrow (17 Jul): Sunny and Very Warm. Winds Likely Remaining Northerly. 58/93 Sat (18 Jul): Mostly Sunny but Not As Warm. Increasing Onshore Flow. 59/88 Sun (19 Jul): Areas of Morning Clouds. Mostly Sunny but Cooler. 56/79 Mon (20 Jul): Morning Clouds. Mostly Sunny in the Afternoon. 52/82 Tue (21 Jul): Mostly Sunny. 52/85 Wed (22 Jul): Patchy Morning Clouds. Mostly Sunny. 55/83 Thu (23 Jul): Patchy Morning Clouds. Mostly Sunny. 54/85 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Jul 17 09:00:16 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 17 Jul 2009 11:00:16 -0500 Subject: [willamette-fcst] Forecast - Friday, July 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. Issued: Friday, July 17th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 1:00pm until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A broad upper-level ridge of high pressure remains over the regin today, and the air mass is starting off a few degrees warmer than on Thursday. Minimums in the Willamette Valley this morning were mostly in the upper 50s and low 60s. Hillsboro and Eugene were the cool spots with 56, while Portland, Aurora, and Corvallis stayed in the 60s overnight. The mid-morning ODA surface analysis showed a thermal trough over southwestern Oregon extending northward, through the Willamette Valley, into east-central Washington. Weak high pressure centers were over northeast and south-central Oregon, as well as the central Oregon Coast. Winds across the entire state were less than 10 mph with calm winds over most of the Willamette Valley. Satellite imagery illusstrated the southwesterly flow aloft via high clouds streaming northeastward across Oregon. Once again this morning, there were areas of low clouds and fog along the immediate coastline, with some eastward penetration of low clouds into the coastal mountain gaps south of about Florence. The upper-level ridge will continue to slowly drift eastward today and will be centered over Idaho and western Montana this afternoon. The surface thermal trough is forecast to remain over western Oregon most of today, before shifting into central Oregon late this afternoon. High temperatures today will range from the 60s on the central and south coast, where low clouds will be the most persistent, to the mid 70s on the north coast. Willamette Valley highs today should climb into the mid 90s, after peaking in the low 90s Wednesday afternoon. Temperatures will likely climb over 100 degrees this afternoon over sections of southwestern Oregon and from the eastern Columbia Gorge through the Columbia Basin of northeastern Oregon. The remainder of central and eastern Oregon will soar well into the 90s. Surface and transport winds across the Willamette Valley are forecast to remain northerly today, with a slight chance of turning northwesterly late this afternoon. Weather conditions will be closely monitored this afternoon, but it is unlikely that the transport winds will take on enough of a westerly component to allow for open burning. Much of the valley will also be bordering on State Fire Marshal Conditions this afternoon. Surface Winds: N 3-8 this morning, N 7-15 this afternoon. Transport Winds: NNE 7 this morning, N 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 45. High Temperature: Salem\'s high temperature today will be near 94. Humidities: Relative humidity drops to 50% by 10am. Minimum relative humidity will be near 25%. Sunrise/Sunset: Salem sunset tonight: 8:54pm; sunrise tomorrow: 5:43am. Extended Outlook: The upper-level ridge is forecast to be slightly flattened by a weak weather system moving into southwestern British Columbia on Satruday. Increasing southwesterly flow aloft over Oregon will drive some mid and high-level moisture into central and eastern Oregon for an increasing threat of afternoon and evening thunderstorms. The surface thermal trough, and warmest temperatures, are forecast to shift into eastern Oregon, with increasing onshore flow across the interior of western Oregon. That should cool temperatures back into the 80s across the Willamette Valley. The weak upper-level trough is forecast to slide eastward, into Alberta, Canada, Sunday with the surface thermal trough pushing into Idaho Sunday afternoon. That will usher a weak surge of cooler ocean air across most of Oregon. The extreme southeastern portion of the state will not see much cooling. Willamette Valley highs should cool into the low 80s (near to slightly below normal) with some marine low clouds possibly penetrating into the western valleys Sunday morning. Precipitation west of the Cascades appears as if it will be limited to a chance of drizzle along the coast. The thundershower threat, east of the Cascades, will extend from south-central to extreme northeastern Oregon, as cooler and more stable air surges into north-central Oregon. The upper-level ridge is forecast to begin building back over the region Monday, for a return to mostly sunny and warmer conditions. The afternoon and evening thundershowers will also increase east of the Cascades, with weakening south-southesterly flow aloft. A weak upper-level system may approach the Oregon Coast by late Tuesday or Wednesday of next week and increase the onshore flow slightly. That would keep temperatures near normal and could create a burning opportunity. Much warmer weather apprears likely late next week. Tomorrow (18 Jul): Mostly Sunny but Not As Warm. Increasing Onshore Flow. 59/88 Sun (19 Jul): Areas of Morning Clouds. Mostly Sunny but Cooler. 54/81 Mon (20 Jul): Brief Patchy Morning Clouds. Sunny and Warmer. 54/85 Tue (21 Jul): Mostly Sunny. 55/84 Wed (22 Jul): Mostly Sunny. 55/83 Thu (23 Jul): Mostly Sunny. 55/87 Fri (24 Jul): Mostly Sunny. 56/93 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Jul 20 08:57:35 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 20 Jul 2009 10:57:35 -0500 Subject: [willamette-fcst] Forecast - Monday, July 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. ...State Fire Marshal Conditions may be met this afternoon due to low humidities and wind... Issued: Monday, July 20th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 2:00pm until 8:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The broad upper-level ridge of high pressure that was over the region last week pushed east and allowed a weak influx of marine air into the Willamette Valley over the weekend. That cooled temperatures from the low 90s Thursday and Friday back into the upper 80s Saturday and low to mid 80s (near-normal) Sunday. The upper-level ridge is rebuilding over the region today. Satellite imagery showed considerable low clouds and fog banked up against most ot the Washington and Oregon coastlines this morning, with some high clouds sweeping northward over western Oregon and southwestern Washington. Otherwise, skies were sunny over the region. The onshore flow along the coastal strip will turn northerly this afternoon with skies clearing there. Mostly sunny skies are forecast over the remainder of Oregon today. After starting off mostly in the 50s this morning, Willamette Vally high temperatures will likely hit the low 90s this afternoon. The mid-morning ODA surface analysis showed a thermal trough building northward, from northern California, into western Oregon. Northeasterly transport winds this morning are forecast to increase and turn northerly this afternoon. The combination of low humidities and increasing northerly winds may locally push sections of the Willamette Valley into State Fire Marshal conditions this afternoon...especially south. Surface Winds: N 5-12 this morning, N 7-15 this afternoon. Transport Winds: NNE 12 this morning, N 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3700 feet. Ventilation index 44. High Temperature: Salem\'s high temperature today will be near 91. Humidities: Relative humidity drops to 50% by 10am. Minimum relative humidity will be near 25%. Sunrise/Sunset: Salem sunset tonight: 8:51pm; sunrise tomorrow: 5:46am. Extended Outlook: The upper-level ridge axis is forecast to shift eastward, to near the Oregon/Idaho border, by Tuesday afternoon, with increasing southwesterly flow aloft over western Oregon. That should keep temperatures from climbing much higher across western Oregon and may promote a weak afternoon seabreeze into the Willamette Valley. The upper-level ridge axis is forecast to continue to shift eastward Wednesday, to over Idaho and western Montana, but the ridge is also forecast to become more broad, so only a slight increase in southwesterly flow aloft is forecast over western Oregon. That may cool Willamette Valley temperatures a couple of degrees with a possible afternoon seabreeze again. The upper-level ridge axis is forecast to amplify over Idaho Thursday and Friday, with the flow aloft turning more southerly, and warming, over Oregon. That will open the door for more subtropical moisture to push northward, into central and Eastern Oregon, which will enhance the threat of afternoon and evening thunderstorms there. However, there should be enough southwesterly flow aloft over western Oregon to keep thunderstorms mainly from the Cascades eastward. The afternoon seabreezes will turn more northerly with Willamette Valley temperatures warming again by Friday. The are significant differences in the long-range models by this weekend, but they all indicate that a strong upper-level ridge of high pressure will develop somewhere near the west coast of North America. Depending on the exact location of the ridge, temperatures across western Oregon have the potential to reach the century mark. The flow aloft may also turn southerly enough to allow for thunderstorm development, west of the Cascades, by early next week. Tomorrow (21 Jul): Mostly Sunny. 59/91 Wed (22 Jul): Mostly Sunny. 56/88 Thu (23 Jul): Sunny. 55/88 Fri (24 Jul): Sunny and Warmer. 56/91 Sat (25 Jul): Sunny and Hot. 58/95 Sun (26 Jul): Mostly Sunny and Hot. Slight Chance of Thunderstorms Late. 60/97 Mon (27 Jul): Mostly Sunny and Hot. Chance of PM Thunderstorms. 61/92 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Jul 21 08:59:23 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 21 Jul 2009 10:59:23 -0500 Subject: [willamette-fcst] Forecast - Tuesday, July 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: Tuesday, July 21st, 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 ridge of high pressure rebuilt over Oregon Monday with the development of a surface thermal trough helping high temperatures climb into the low 90s in the Willamette Valley. The upper-level ridge shifted slightly eastward overnight, to over eastern Oregon, with the surface thermal trough following it into central Oregon. Onshore flow has increased along the coast with visible satellite imagery showing marine low clouds penetrating into the coastal mountain gaps this morning. Skies remained clear, east of the coast range, this morning, with just a slight influx of onshore flow into the Willamette Valley overnight. Skies will be sunny again today, east of the coast range. With the thermal trough staying east of the Cascades today, an afternoon seabreeze will likely cap high temperatures in the upper 80s across the Willamette Valley. Light southwesterly transport this morning should increase and turn west-northwesterly, in respnose to the incoming seabreeze this afternoon. Pressure gradients should become favorable this afternoon for smoke evacuation, from the valley, eastward over the Cascade passes. Surface Winds: SW 5 this morning, NW 5-12 this afternoon. Transport Winds: SW 5 this morning, WNW 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4500 feet. Ventilation index 36. High Temperature: Salem\'s high temperature today will be near 88. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 33%. Sunrise/Sunset: Salem sunset tonight: 8:50pm; sunrise tomorrow: 5:47am. Extended Outlook: The upper-level ridge axis is forecast to continue to shift eastward Wednesday, to over Idaho and western Montana, with the surface thermal trough shifting to eastern Oregon. Patchy morning clud may penetrate into the Willamette Valley. Once again, an afternoon seabreeze will likely create favorable ventilation conditions for burning in the Willamette Valley. Temperatures will likely be a couple of degrees cooler, with valley highs in the mid to upper 80s. The upper-level ridge axis is forecast to amplify over Idaho Thursday, with the flow aloft turning more southerly over Oregon. That will open the door for more subtropical moisture to push northward into central and Eastern Oregon, which will enhance the threat of afternoon and evening thunderstorms there. Onshore flow will decrease west of the Cascades Thursday, with temperatures starting to warm back up. There may still be enough of an afternoon seabreeze to provide adequate ventilation for burning. A weak weather system is now forecast to ride over the ridge and into southern British Columbia Friday. That may promote the continuation of the afternoon seabreeze pattern, but that is getting too far out to call that closely. In any case, no major change to the weather pattern is forecast through this week, with possible burning opportunities each afternoon. The are still significant differences in the long-range models by this weekend, with the latest guidance suggesting that the weak system cutting across southern British Columbia will keep the thermal trough east of the Cascades and weak onshore flow across western Oregon. That would maintain the sunny and dry pattern but keep temperatures from climing much higher than the low to mid 90s across the Willamette Valley. The ridge is forecast to amplify over the region early next week, with the thermal trough coming back west of the Cascades and warming temperatures possibly to near the century mark in the Willamette Valley. Tomorrow (22 Jul): Patchy AM Clouds. Sunny. 55/86 Thu (23 Jul): Sunny. 55/88 Fri (24 Jul): Sunny. 55/88 Sat (25 Jul): Sunny and Warmer. 57/92 Sun (26 Jul): Sunny and Very Warm. 58/93 Mon (27 Jul): Sunny and Very Warm. 58/94 Tue (28 Jul): Sunny and Hot. 59/97 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Jul 22 09:00:54 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 22 Jul 2009 11:00:54 -0500 Subject: [willamette-fcst] Forecast - Wednesday, July 22nd, 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, July 22nd, 2009 at 9:00am. 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. Straw stack burning is allowed from 11:00am until 8:00pm. Weather Discussion: The upper-level ridge of high pressure that has been over the region shifted far enough to the east to allow an influx of cooler ocean air into the Willamette Valley overnight. Visible satellite imagery this morning showed that marine low clouds were able to penetrate east of the coast range and into sections of the Willamette Valley...especially in the extreme north valley, near the Columbia River, and in the south valley, across most of Lane County. That helped cool Willamette Valley temperatures well down into the 50s this morning, after maximums on Tuesday near 90 degrees. The coastline was blanketed with low clouds again this morning, and there were some pockets of drizzle and/or light rain. Astoria and Newport both picked up .01 inches this morning. There were no reports of rain east of the coast range. Skies were clear this morning over the interior of southwestern Oregon and all areas east of the Cascade crest. The Salem sounding this morning showed a few degrees of cooling, from the surface up to about 12,000 feet, in response to the increase in onshore flow. The ODA surface analysis showed the thermal trough had shifted further eastward overnight...extending from east-central Washington southward through south-central Oregon. The weak marnine push overnight resulted in a gradient-stacking pattern this morning, with onshore gradients stronger across central Oregon than over western Oregon. That pressure pattern does not promote good lifting of smoke over the Cascade passes. However, the gradient-stacking is not severe, so it is likely that daytime heating overcome it by mid-afternoon. The upper-level ridge will weaken and shift slightly further east today, with continued onshore flow at the surface. Areas of valley low clouds this morning should give way to sunshine this afternoon. With stronger onshore flow, temperatures will be cooler today. Valley highs should top out in the mid 80s. Transport winds are light southwesterly this morning and are forecast to become northwesterly this afternoon...increasing in response to the seabreeze this evening. Mixing heights should climb to near 3000 feet around midday and above 4000 feet by late this afternoon. Surface Winds: SW 5 this morning, NW 5-15 this afternoon. Transport Winds: W 5 this morning, NW 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: 8:49pm; sunrise tomorrow: 5:48am. Extended Outlook: The upper-level ridge axis is forecast to remain over eastern Idaho and western Montana Thursday, as a weak upper-level disturbance slides across Washington. Onshore flow could become strong enough to produce morning drizzle along the coast again Thursday morning. Marine low clouds will likely penetrate into the Willamette Valley, Thursday morning, but no rain is expected east of the coast range. Skies should clear Thursday afternoon over the Willamette Valley, but high temperatures will likely be a few degrees cooler. There may be an open burning opportunity again Thursday afternoon, if daytime heating can overcome morning gradient-stacking. The upper-level disturbance is forecast to weaken over eastern Washington Friday and Saturday with onshore flow weakening across western Oregon. Any morning clouds should quickly give way to sunshine, with temperatures rebouding back above normal. Northwesterly transport winds may become too northerly to allow for open burning. The ridge is forecast to amplify over Washington and Oregon Sunday, as the weak upper-level disturbance drops southeastward to over Idaho. That would force the thermal trough back west of the Cascades...shutting off the onshore flow. Temperatures will likely climb well into the 90s with sunny skies. There is some indication that the upper-level ridge may become strong enough to send Willamette Valley temperatures to the century mark early next week, but that is still uncertain at this time. Tomorrow (23 Jul): AM Clouds...Becoming Sunny. A Little Cooler. 52/82 Fri (24 Jul): Brief AM Clouds...Sunny and Warmer. 52/85 Sat (25 Jul): Patchy AM Clouds...Sunny and Warmer. 55/91 Sun (26 Jul): Sunny and Hot. 57/96 Mon (27 Jul): Sunny and Hot. 60/100 Tue (28 Jul): Sunny and Hot. 62/100 Wed (29 Jul): Sunny and Hot. 62/100 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Jul 23 08:52:52 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 23 Jul 2009 10:52:52 -0500 Subject: [willamette-fcst] Forecast - Thursday, July 23rd, 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, July 23rd, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 11:00am until 8:00pm. Preparatory burning is allowed from 11:00am until 2:00pm with a 50 acre limit. Propane flaming is allowed from 11:00am until 2:00pm. Stack burning is not allowed. Weather Discussion: A very weak upper-level trough will cut across Washington today and maintain onshore flow across western Oregon. Satellite imagery showed the marine low clouds extended from the coast to the crest of the Cascades this morning and will be slower to give way to sunshine than they were yesterday. As a result, valley temperatures will be a few degrees cooler today. Highs will peak in the upper 70s to low 80s, after hitting the low to mid 80s Wednesday. The morning sounding over Salem was a few degrees cooler, everywhere below 35,000 feet, compared with yesterday morning. Transport winds were light north-northwesterly and are forecast to be mostly northerly this afternoon. The mid-morning ODA surface analysis showed high pressure building into the Oregon coast and slightly more significant gradient-stacking than yesterday morning, due to the strong surge of marine air into the Willamette Valley last night. The thermal trough, which was over central Oregon yesterday, had shifted into Idaho. With cooler air aloft, mixing heights should climb to near 3000 feet by midday, which will provide adequate ventilation for propane flaming and limited prep burning. However, a later break-out from the marine low clouds today will not give the sun as much chance to warm the valley and reverse the gradient-stacking pattern this afternoon. In addition, transport winds are forecast to be more northerly than yesterday afternoon. We will, of course, monitor both the transport winds and pressure gradients this afternoon, on the outside chance they turn more favorable for open burning. Surface Winds: NNW 5-12 this morning, NW 8-15 G20 south this afternoon. Transport Winds: NNW 8 this morning, N 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 4100 feet. Ventilation index 49. 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 39%. Sunrise/Sunset: Salem sunset tonight: 8:48pm; sunrise tomorrow: 5:49am. Extended Outlook: The upper-level disturbance, over Washington, is forecast to weaken and drift slowly eastward, to over northern Idaho, Friday and Saturday. That should weaken the onshore flow across western Oregon, allowing any morning clouds to more quickly give way to sunshine with warming temperatures. Transport winds will likely be too northerly to allow for open burning. The upper-level ridge is forecast to amplify over Washington and Oregon Sunday, as a weak upper-level disturbance drops southeastward across Idaho. That may force the thermal trough back west of the Cascades...shutting off the onshore flow for continued warming temperatures. It now appears likely that the upper-level ridge will further strengthen along the west coast of North America early next week, with the surface thermal trough building northward over western Oregon. That would help Willamette Valley temperatures climb to near, or above, the century mark...perhaps for several days. The latest comuter guidance is even suggesting that the thermal trough may eventually move offshore and allow very warm temperatures to extend westward to the coastline. Those details will become more clear by Monday. Tomorrow (24 Jul): Brief AM Clouds...Sunny and Warmer. 52/86 Sat (25 Jul): Brief Patchy AM Clouds...Sunny and Even Warmer. 56/92 Sun (26 Jul): Sunny and Hot. 58/96 Mon (27 Jul): Sunny and Hot. 60/100 Tue (28 Jul): Sunny and Hot. 62/102 Wed (29 Jul): Sunny and Hot. 60/101 Thu (30 Jul): Sunny and Hot. 59/98 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Jul 24 08:59:26 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 24 Jul 2009 10:59:26 -0500 Subject: [willamette-fcst] Forecast - Friday, July 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: Friday, July 24th, 2009 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 11:00am until 8:00pm. Preparatory burning is allowed from 11:00am until 2:00pm with a 50 acre limit. Propane flaming is allowed from 11:00am until 2:00pm. Stack burning is not allowed. Weather Discussion: Strong onshore flow and extensive morning low clouds held high temperatures in the upper 70s and low 80s across the Willamette Valley Thursday. A very weak upper-level low-pressure center will remain nearly stationary over eastern Washington today. That has helped to maintain weak onshore flow across western Oregon. Visible satellite imagery showed only patchy marine low clouds along the coast and in the Willamette Valley this morning, with mid-morning temperatures near 60 degrees. The Salem sounding from early this morning showed several degrees of warming aloft, from 3000-10,000 ft, so maximum mixing heights will be lower today. However, mixing heights should climb to around 3000 feet by midday, which will provide adequate ventilation for propane flaming and limited prep burning. The ODA surafce analysis showed much less onshore flow across western Oregon this morning. Mid-morning winds were already mostly northerly, from the coast to the Cascades, with gradients forecast to turn progressively more northerly this afternoon. Low clouds will evaporate much sooner today, with warmer air aloft allowing the hot July sun to lift valley highs into the mid to upper 80s this afternoon. Surface Winds: N 5-12 this morning, N 7-15 G20 south this afternoon. Transport Winds: NNE 10 this morning, N 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3800 feet. Ventilation index 38. 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 33%. Sunrise/Sunset: Salem sunset tonight: 8:47pm; sunrise tomorrow: 5:50am. Extended Outlook: A nearly-stationary small upper-level low pressure area is forecast to remain over eastern Washington on Saturday. That will keep the upper-level ridge from building too quickly back over Oregon and maintain very weak onshore flow west of the Cascades. Only patchy morning clouds inland will burn off quickly with afternoon temperatures likely warming into the 90s. The upper-level disturbance is forecast to slowly drift southeastward, across Idaho, Sunday and Monday, with the upper-level ridge strongly rebuilding along the coastline and into southern British Columbia. By Monday, a surface thermal trough will build northward, into western Oregon, with the low-level flow turning offshore. The region will experience the warmest temperatures so far this year with Willamette Valley highs likely climing over the century mark. The long-range computer models are consistent in forecasting a prolonged period of hot weather...lasting at least through most of next week. Willamette Valley high temperatures may break 100 degrees several days in-a-row. It also apprears that the thermal trough may move far enough west to allow the hot offshore surface winds to extend to the coast, at least during the first half of next week. The impressively strong upper-level ridge is forecast to finally begin shifting eastward late next week, which would return onshore flow, and much cooler temperatures, to the immediate coastline. As the ridge continues to shift eastward, increasing southerly flow aloft will introduce a chance of thunderstorms, and progressively cooler temperatures, across the state by next weekend...a typical scenario following an intense heat-wave. Tomorrow (25 Jul): Brief Patchy AM Clouds...Sunny and Even Warmer. 57/91 Sun (26 Jul): Sunny and Hot. 58/95 Mon (27 Jul): Sunny and Hot. 60/100 Tue (28 Jul): Sunny and Hot. 62/103 Wed (29 Jul): Sunny and Hot. 63/103 Thu (30 Jul): Sunny and Hot. 64/101 Fri (31 Jul): Sunny and Hot. 63/99 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Jul 27 10:59:15 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 27 Jul 2009 12:59:15 -0500 Subject: [willamette-fcst] Forecast - Monday, July 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. ...State Fire Marshal Conditions will likely be met this afternoon... Issued: Monday, July 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 heat-wave pattern is developing for most of Oregon, with a strong upper-level ridge of high pressure rapidly building along the west coast of North America. The morning ODA surface analysis showed a thermal trough extending from southwestern Oregon northward through the Willamette Valley. Minimum temperatures in the Willamette Valley this morning were quite warm...especially in urban regions. The Salem Airport recorded a preliminary low temperature this morning of a balmy 70 degrees, and Portland only dropped to 68. Eugene did manage to fall down to 62 degrees and Corvallis dipped to 63. Mid-morning temperatures had already warmed into the mid 70s in some sections of the valley. The Salem sounding this morning showed several degrees of warming aloft, compared with Sunday afternoon, with offshore flow. Since high temperatures Sunday warmed into the low to mid 90s across the Willamette Valley, it is reasonable to expect high temperatures today to hit the century mark in many valley locations. Maximums will soar well over 100 degrees in southwestern Oregon, with 90s and low 100 common across central and eastern Oregon. The immediate coastline will get some relief from the heat today. Weak onshore flow was pushing a shallow layer of low clouds and fog onto the beaches, with mid-morning temperatures in the low to mid 50s. The low clouds should back away from the beaches this afternoon, with high temperatures ranging from the mid 60s along the south coast to near 80 on the extreme north coast. Surface Winds: N 3-8 this morning, N 5-15 this afternoon. Transport Winds: NNE 10 this morning, N 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3200 feet. Ventilation index 38. High Temperature: Salem\'s high temperature today will be near 100. Humidities: Minimum relative humidity will be near 26%. Sunrise/Sunset: Salem sunset tonight: 8:44pm; sunrise tomorrow: 5:54am. Extended Outlook: The long-range computer models are consistent in forecasting a prolonged period of hot weather...lasting at least through most of this week. Willamette Valley high temperatures will likely top 100 degrees for several straight days, and overnight minimums will struggle to get much below 70 degrees in urban areas. It also appears that the thermal trough may move far enough west to allow the hot offshore surface winds to extend to sections of the coast, especially north, Tuesday and Wednesday. The impressively strong upper-level ridge may shift eastward enough by Thursday to return onshore flow, and much cooler temperatures, to the immediate coastline. Some weak onshore flow may begin seeping into the Willamette Valley Thursday afternoon, but not likely in time to keep much of the valley from seeing a fourth straight 100-degree afternoon. The long-range computer models are indicating that the upper-level ridge will shift far enough east to send the thermal surface trough east of the Cascades by Friday afternoon...beginning a cool-down across the interior of western Oregon. By the weekend, increasing southerly flow aloft may introduce a chance of thunderstorms to most of the state, especially south, along with cooling temperatures. That would be a typical scenario following an intense heat-wave, but the computer models are still not clear on the details of how this hot pattern will break down. Tomorrow (28 Jul): Sunny and Hot. 69/103 Wed (29 Jul): Sunny and Hot. 69/104 Thu (30 Jul): Sunny and Hot. 67/101 Fri (31 Jul): Sunny and Not as Hot. Increasing onshore flow. 62/93 Sat (01 Aug): Partly Cloudy. Muggy. Chance of T-Storms. Cooler. 60/88 Sun (02 Aug): Mostly Cloudy. Muggy. Chance of T-Storms. 59/87 Mon (03 Aug): Mostly Cloudy. Chance of Showers or T-Storms. 59/82 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Jul 28 08:37:31 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 28 Jul 2009 10:37:31 -0500 Subject: [willamette-fcst] Forecast - Tuesday, July 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. ...State Fire Marshal Conditions will likely be met by early this afternoon... Issued: Tuesday, July 28th, 2009 at 8:35am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Temperatures soared over 100 degrees across the Willamette Valley Monday afternoon, with the hot and dry air sending the valley into State Fire Marshall conditions. Many locations approached their daily record high temperatures Monday, but most of the established records were quite warm due to a hot spell in 1998. Eugene reached 102 degrees. Salem and Corvallis hit 103...none of which was a record. However, 103 degrees at Portland and Troutdale did set new daily record highs. Most daily records in the valley are much lower today, so many should be broken. One all-time record that was tied yesterday was the warmest minimum temperature in Salem, at 70 degrees. That may be broken today, because the recorded minimum, so far this morning, at the Salem Airport was 71 degrees. The final minimum will be reported by the automated weather station at 11am, but this could be the warmest morning on record in Salem. Of course, the growth of the city over the past century makes that record less meaningful, because of the urban heat-island effect, but it is still a long-standing record (over a century) that may be broken today. A strong upper-level ridge of high pressure remains parked along the west coast of North America this morning. On the surface, a well-developed thermal heat-low extends northward across the Willamette Valley and into southwestern Washington. Dry northerly or northeasterly flow and clear skies prevail across all of western Oregon this morning, except for along the southern coast. Temperatures range from near 50 on the south coast, with low clouds and fog, to the 60s on the north coast, under sunny skies. Inland, mid-morning temperatures were running several degrees warmer than 24 hours ago, with some Willamette Valley locations already in the low 80s. It promises to be a scorcher today across the interior of western Oregon. Willamette Valley highs should climb even warmer than on Monday with many locations maxing out around 105 degrees. Dry north-northeasterly flow and hot temperatures will likely push most of the Willamette Valley into State Fire Marshal Conditions by 2-3pm this afternoon. With the thermal trough expanding to the coast, temperatures there should climb into the 70s and 80s today. The warmest coastal temperatures will be in the north, with onshore flow more reluctant to give way on the south coast. Surface Winds: N 3-8 this morning, N 5-15 this afternoon. Transport Winds: NNE 8 this morning, N 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 105. Humidities: Relative humidity drops to 50% by 10am. Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 8:43pm; sunrise tomorrow: 5:55am. Extended Outlook: Computer models show little change in the weather pattern Wednesday and Thursday, with more record-breaking heat across western Oregon. Willamette Valley highs will likely cool a couple of degrees by Thursday but may still top 100 degrees. Overnight minimums will continue to struggle to get much below 70 degrees in urban areas. The impressively strong upper-level ridge may shift eastward enough by Thursday to return onshore flow to the immediate coastline for more pronounced cooling there...especially from about Newport south. The upper-level ridge is forecast to shift far enough east by Friday to send the surface thermal trough east of the Cascades. That should bring enough onshore flow into western Oregon to cool Willamette Valley highs back into the 90s. By the weekend, increasing southerly flow aloft may introduce a chance of thunderstorms to most of the state, along with moderating temperatures. That would be a typical scenario following an intense heat-wave, but the computer models are still not clear on the details of how this hot pattern will break down. Tomorrow (29 Jul): Sunny and Hot. 70/105 Thu (30 Jul): Sunny and Hot. 67/100 Fri (31 Jul): Sunny. A Little Cooler with Weak Onshore Flow. 62/95 Sat (01 Aug): Partly Cloudy. Muggy. Chance of T-Storms. 62/93 Sun (02 Aug): Mostly Cloudy. Muggy. Chance of T-Storms. 60/90 Mon (03 Aug): Mostly Cloudy. Chance of Showers or T-Storms. Cooler. 58/86 Tue (04 Aug): Mostly Cloudy. Chance of Showers and T-Storms. 57/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Jul 28 12:08:45 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 28 Jul 2009 14:08:45 -0500 Subject: [willamette-fcst] Forecast - Tuesday, July 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. NOON UPDATE Issued: Tuesday, July 28th, 2009 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Two all-time records were tied this morning. Portland recorded a minimum of 74 degrees and Salem only dipped down to 70, for the second straight morning. Both cities tied their all-time record warm minimum temperature. It is possible that one or both records could be broken tomorrow, as the air mass continues to heat up. Of course, the growth of those cities, over the past century, makes that particular record less meaningful, because of the urban heat-island effect. However, those very warm overnight temperatures highlight the significance of this summer heat-have across western Oregon. Temperatures were able to drop into the 60s across much of the Willamette Valley this morning. Eugene dropped to 62 degrees, Corvallis fell to 63, and McMinnville dipped to 65 degrees. A strong upper-level ridge of high pressure remains parked along the west coast of North America today. On the surface, a well-developed thermal heat-low extends northward across the Willamette Valley and into southwestern Washington. It is expanding eastward, into the Columbia Gorge, and westward, to the Oregon Coast. Dry northerly or northeasterly flow and clear skies prevailed across all of western Oregon late this morning. Morning low clouds and fog had even cleard from the southern coast. Midday temperatures ranged from the low 60s on the south coast to the upper 70s on the north coast. Coastal temperatures should climb into the 70s south and 80s north today. Inland valley locations were running 3-6 degrees warmer than 24 hours ago with much of the Willamette Valley already in the low 90s. Willamette Valley highs should climb to around 105 degrees today...easily breaking daily records and approaching the all-time records for Portland (107 degrees), Salem (108 degrees) and Eugene (108 degrees), which were set in August, 1981. Hot temperatures and low humidities will push the Willamette Valley into State Fire Marshal Conditions early this afternoon. Surface Winds: N 5-15 this afternoon. Transport Winds: N 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 105. Humidities: Minimum relative humidity will be near 21%. Sunrise/Sunset: Salem sunset tonight: 8:43pm; sunrise tomorrow: 5:55am. Extended Outlook: Computer models show little change in the weather pattern Wednesday, with more record high temperatures likely across western Oregon. Some minor cooling is forecast for late Thursday, as the thermal trough begins shifting eastward. Overnight minimums will continue to stay near or above 70 degrees in places like Portland and Salem, with mid 60s common across the valley. The upper-level ridge is forecast weaken a little on Friday with increasing westerly flow aloft. That should shift the surface thermal trough east of the Cascades and bring enough onshore flow into western Oregon to cool Willamette Valley highs back into the 90s. By the weekend, an approaching upper-level trough may increase the southerly flow aloft enough to introduce a chance of thunderstorms to most of the state. That would be a typical scenario following an intense heat-wave. The speed of the ultimate cool-down appears as if it will be gradual, but that is still in question. Also in question is whether or not the cool-down will present a burning opportunity. Tomorrow (29 Jul): Sunny and Hot. 70/105 Thu (30 Jul): Sunny and Hot. 67/100 Fri (31 Jul): Sunny. A Little Cooler with Weak Onshore Flow. 62/95 Sat (01 Aug): Partly Cloudy. Muggy. Chance of T-Storms. 62/93 Sun (02 Aug): Mostly Cloudy. Muggy. Chance of T-Storms. 60/90 Mon (03 Aug): Mostly Cloudy. Chance of Showers or T-Storms. Cooler. 58/86 Tue (04 Aug): Mostly Cloudy. Chance of Showers and T-Storms. 57/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Jul 29 08:40:41 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 29 Jul 2009 10:40:41 -0500 Subject: [willamette-fcst] Forecast - Wednesday, July 29th, 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 early this afternoon... Issued: Wednesday, July 29th, 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: Tuesday was a scorcher across all of western Oregon except for right along the immediate coastline. Willamette Valley temperatures approached all-time record highs late Tuesday afternoon and easily soared past the daily records. Salem hit 107 degrees and Portland peaked at 106, both missing their all-time record highs by just 1 degree. Eugene, Aurora, and McMinnville also hit 106 degrees. Roseburg, Medford, and The Dalles were the hot spots in the state with 108 degrees. The beaches were mostly in the 70s and 80s, but temperatures soared over 100 as far west as the coast range passes. Central and eastern Oregon highs were mostly in the 90s and low 100s. Slightly drier air allowed temperatures to dip a couple of degrees lower than Tuesday morning across the northern Willamette Valley. Portland dipped to 72 this morning, after tying the all-time record warm minimum Tuesday morning with 74. Salem was also a touch cooler this morning with a low of 69, after tying the all-time record warm minimum of 70 the past two mornings. Minimums were mostly in the mid 60s across the rest of the Willamette Valley. No major changes are forecast to the general weather pattern today, so one more ultra-hot day is in store, before a slow cooling trend begins. The surface thermal trough was well developed and extended northward from southwestern Oregon through western Washington. The trough had moved just inland over western Oregon but continued to extend to the coastline in western Washington. Visible satellite imagery showed more extensive low clouds and fog along the Oregon coast this morning...stretching all the way north to the mouth of the Columbia River. That will cool temperatures today along the immediate coastline, but sunny skies and very warm air aloft will combine to bring another record-breaking afternoon to the interior of western Oregon. Willamette Valley temperatures should be within a degree or two of where they were on Tuesday. Like yesterday, State Fire Marshal conditions will likely be met across the Willamette Valley by early this afternoon, due to high temperatures and low relative humidity. Also like yesterday, increasing northerly winds, in the afternoon, will add to the fire danger potential. Surface Winds: Var 0-5 this morning, N 5-15 this afternoon. Transport Winds: NE 4 this morning, NNW 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5500 feet. Ventilation index 44. High Temperature: Salem\'s high temperature today will be near 107. Humidities: Minimum relative humidity will be near 20%. Sunrise/Sunset: Salem sunset tonight: 8:42pm; sunrise tomorrow: 5:56am. Extended Outlook: Some minor cooling is forecast for late Thursday, as the thermal trough begins shifting eastward. Willamette Valley highs will back off to the 95-100 degree range. Overnight minimums will also cool back into 60s and upper 50s...making it feel a little more confortable. The upper-level ridge is forecast weaken some on Friday with increasing westerly flow aloft. That should shift the surface thermal trough east of the Cascades and bring enough onshore flow into western Oregon to cool Willamette Valley highs back into the low to mid 90s. By the weekend, an approaching upper-level trough may increase the southerly flow aloft enough to introduce a chance of thunderstorms to most of the state. That would be a typical scenario following an intense heat-wave. The speed of the ultimate cool-down appears as if it will be gradual, with a little more marine air seeping into the western valleys each day. Due to the forecast south-southeaseterly flow aloft, it is not clear whether or not this cool-down will create any burning opportunities. Tomorrow (30 Jul): Sunny and Hot. 66/100 Fri (31 Jul): Sunny. A Little Cooler with Weak Onshore Flow Developing. 64/95 Sat (01 Aug): Partly Cloudy. Muggy. Chance of T-Storms. 62/93 Sun (02 Aug): Mostly Cloudy. Muggy. Good Chance of T-Storms. 60/89 Mon (03 Aug): Mostly Cloudy. Chance of Showers or T-Storms. Cooler. 57/86 Tue (04 Aug): Mostly Cloudy. Chance of Showers and T-Storms. 56/83 Wed (05 Aug): Mostly Cloudy. Chance of Showers and T-Storms. 55/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Jul 29 12:15:41 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 29 Jul 2009 14:15:41 -0500 Subject: [willamette-fcst] Forecast - Wednesday, July 29th, 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: Wednesday, July 29th, 2009 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Slightly drier air allowed temperatures to dip a couple of degrees lower than Tuesday morning across the northern Willamette Valley. Portland dipped to 71 this morning, after tying the all-time record warm minimum Tuesday morning with 74. Salem was also a touch cooler this morning with a low of 68, after tying the all-time record warm minimum of 70 the past two mornings. Minimums were mostly in the mid 60s across the rest of the Willamette Valley. No major changes are forecast to the general weather pattern today, so one more ridiculously hot day is in store, before a slow cooling trend begins. The late-morning ODA surface analysis showed a well-developed surface thermal trough extending northward from southwestern Oregon through western Washington. The trough had moved just inland over western Oregon but continued to extend to the coastline in western Washington and extreme northern Oregon. Midday visible satellite imagery showed a shallow layer of low clouds and fog extending northward, along the Oregon Coast, to just south of the mouth of the Columbia River. Skies were sunny over the remainder of the state with only a few cumulus clouds beginning to develop...mainly over the mountains of eastern Oregon. Midday coastal conditions ranged from the cloudy and cool upper 50s in Brookings (extreme south coast)to sunny skies and near 70 degrees at Astoria (extreme north coast). Due to the increase in onshore flow, the central and southern beaches will be cooler today, with highs staying in the 60s. The north coast will climb into the 70s and locally the 80s. Temperatures were much warmer just inland, with most of the Willamette Valley already in the low 90s. Many Willamette Valley locations are running a degree or two warmer than 24 hours ago, so all-time high temperature records of 107 degrees in Portland and 108 degrees in Salem and Eugene could be reached late this afternoon. Like yesterday, State Fire Marshal conditions will likely be met across the Willamette Valley early this afternoon, due to high temperatures and low relative humidity. With the thermal trough directly over the Willamette Valley, the hot and dry northerly winds will be lighter this afternoon. Surface Winds: N 5-10 this afternoon. Transport Winds: NNW 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5500 feet. Ventilation index 44. High Temperature: Salem\'s high temperature today will be near 107. Humidities: Minimum relative humidity will be near 20%. Sunrise/Sunset: Salem sunset tonight: 8:42pm; sunrise tomorrow: 5:56am. Extended Outlook: Some minor cooling is forecast for late Thursday, as the thermal trough begins shifting eastward. Willamette Valley highs should only back off to the 95-100 degree range. Overnight minimums will also cool back into the upper 50s and 60s...making it feel a little more confortable. The upper-level ridge is forecast to shift over eastern Oregon Friady, with the broad surface thermal trough finally sliding east of the Cascades. Weak onshore flow will cool western Oregon temperatures a bit more. By the weekend, an approaching upper-level trough is forecast to turn the flow aloft south-southesterly...introducing at least a chance of thunderstorms to the state by Saturday evening...especially south and over the Cascades. Southeasetery flow aloft is expected to continue strengthening Sunday, which would expand the thunderstorm threat across the state. That would be a typical scenario following an intense heat-wave and will be closely monitored for wildfire potential. The speed of the upcoming cool-down appears as if it will be gradual, with a little more marine air seeping into the western valleys each day. It is unlikely that any burning opportunities will be created later this week, but we will keep a close eye on things. Tomorrow (30 Jul): Sunny and Hot. 66/100 Fri (31 Jul): Sunny. A Little Cooler with Weak Onshore Flow Developing. 64/95 Sat (01 Aug): Partly Cloudy. Muggy. Chance of T-Storms. 62/93 Sun (02 Aug): Mostly Cloudy. Muggy. Good Chance of T-Storms. 60/89 Mon (03 Aug): Mostly Cloudy. Chance of Showers or T-Storms. Cooler. 57/86 Tue (04 Aug): Mostly Cloudy. Chance of Showers and T-Storms. 56/83 Wed (05 Aug): Mostly Cloudy. Chance of Showers and T-Storms. 55/83 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Jul 30 09:00:46 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 30 Jul 2009 11:00:46 -0500 Subject: [willamette-fcst] Forecast - Thursday, July 30th, 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 may be met late this afternoon... Issued: Thursday, July 30th, 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: Wednesday was another record-breaker with Willamette Valley highs climbing above 100 degrees for the third straight day. Daily records were broken from Portland to Eugene, but all-time records were not reached. The story was a little different for our neighbors to the north, in Washington. Seattle set an all-time record high with 103 degrees, as did Olympia with 104 and Vancouver with 108. Willamette Valley highs ranged from 104 in Corvallis to 108 in Aurora. For the second straight day, Portland hit 106...missing their all-time high by just one degree. Salem and Eugene were both one degree cooler than on Wednesday with highs of 106 and 105 respectively. Today is starting off much cooler in the central and southern Willamette Valley, with a shallow layer of marine air dropping temperautures into the upper 50s and low 60s. The cooler air was felt as far north as Aurora, with the immediate Portland area staying in the 70s overnight. Satellite imagery showed marine low clouds along the entire coast with some penetration int the extreme southern valley, near Eugene. The upper-level ridge is not budging, so the patchy low clouds in the south valley should quickly give way to sunshine this morning. The thermal trough is still over the Willamette Valley this morning and is only forecast to slide as far east as central Oregon this afternoon. Due to the shallow layer of cooler marine air mixing into the low-levels of the atmosphere, daytime highs will likely be about 10 degrees cooler across most of the valley. The warmest temperatures will likely be in the Portland area this afternoon. The Salem sounding continued to show very warm air aloft, which should keep mixing heights at or below 4000 feet today. The weak onshore flow will improve ventilation conditions this afternoon, but much of the valley will be flirting with State Fire Marshal Conditions. Surface Winds: SW 5-10 this morning, W 5-15 this afternoon. Transport Winds: SW 5 this morning, W 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3800 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 96. Humidities: Relative humidity drops to 50% by 10am. Minimum relative humidity will be near 26%. Sunrise/Sunset: Salem sunset tonight: 8:41pm; sunrise tomorrow: 5:57am. Extended Outlook: The upper-level ridge is forecast to rebuild over the region somewhat on Friday with only very weak onshore flow. Some south valley temperatures may even warm a degree or two warmer from Thursday with highs generally in the mid 90s. Over the weekend, an approaching upper-level trough is forecast to turn the flow aloft more southerly...increasing the chance of afternoon and evening thunderstorms across mainly the southern half of the state. Little change in temperatures is expected west of the Cascades Saturday, with increasing onshore flow cooling temperatures a few degrees on Sunday. Progreesively cooler temperatures are likely next week, as the thermal trough is forced well east of the Cascades and stronger onshore flow penetrates into the western valleys. Continued southerly flow aloft will further increase the chance of afternoon and evening showers and thunderstorms. Tomorrow (31 Jul): Sunny and Very Warm. 60/95 Sat (01 Aug): Sunny ane Very warm. 59/95 Sun (02 Aug): Parly Cloudy. Chance of T-Storms...Mainly South. 59/91 Mon (03 Aug): Mostly Cloudy. Chance of Showers or T-Storms. Cooler. 57/86 Tue (04 Aug): Mostly Cloudy. Chance of Showers and T-Storms. 56/85 Wed (05 Aug): Mostly Cloudy. Chance of Showers and T-Storms. 55/79 Thu (06 Aug): Mostly Cloudy. Slight Chance of Showers. 53/78 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Jul 31 08:54:21 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 31 Jul 2009 10:54:21 -0500 Subject: [willamette-fcst] Forecast - Friday, July 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: Friday, July 31st, 2009 at 8:50am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Slight weakening of the massive upper-level ridge of high pressure over the west coast of North America allowed for weak onshore flow to penetrate into the interior of western Oregon Thursday. Temperatures in the Willamette Valley generally cooled 10-15 degrees from the record shattering heat on Wednesay but were still above normal. Highs ranged from the upper 80s in the south valley to the mid 90s in the Portland area. The surface thermal trough shifted only as far east as the Cascades, with the hottest condtions shifting into north-central Oregon. Hood River (103 degrees) and The Dalles (105 degrees) soared well over 100 degrees. The triple-digit heat continued in southwestern Oregon, with Medford tying The Dalles for the hot spot in the state at 105 degrees. Converging surface winds, into the thermal trough, and daytime heating helped fuel explosive thunderstorm development along the eastern slopes of the Cascades Thursday afternoon and over central and south-central Oregon. These storms did not have a lot of low-level moisture to work with, so they produced very little rainfall. The upper-level ridge is forecast to strengthen slightly over Oregon today, which may decrease the thunderstorm development over central Oregon, somewhat, this afternoon. Daytime heating and mid-level instability will still likely fuel at least a few storms. West of the Cascades, weak onshore flow was resulting in morning marine clouds along the coast and in sections of the extreme northern and southern Willamette Valley. Those should give way to sunshine this afternoon, even along most of the beaches. Temperatures dropped generally into the 50s in the valley this morning...making it feel much more comfortable. Highs this afternoon will be very similar to yesterday, except for a few additional degrees of cooling in the Portland area. The Salem sounding continued slight cooling aloft but still very warm temperatures in the mid-levels of the atmosphere. As the upper-level ridge rebuilds over oregon today, the air aloft should warm slightly. That will keep mixing heights at or below about 3500 feet this afternoon and maintain the fairly stagnant ventilation conditions across the region. Surface Winds: W 0-5 this morning, NW 5-10 this afternoon. Transport Winds: S 4 this morning, NNW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 25. High Temperature: Salem\'s high temperature today will be near 90. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 33%. Sunrise/Sunset: Salem sunset tonight: 8:39pm; sunrise tomorrow: 5:58am. Extended Outlook: The upper-level ridge is forecast to hold firm over Oregon Saturday, with some increase in southerly flow over the southern half of the state. That will introduce more mid-level moisture into the region for an increased threat of afternoon and evening thunderstorm development. Temperatures will likely warm a few degrees from Friday, with the thermal trough trying to build back westward into the Willamette Valley. By Sunday, the upper-level ridge axis is forcast to finally shift into eastern Oregon with an approaching upper-level trough further increasing the southerly flow aloft over most of the state. Willamette Valley temperatures will either hold steady of cool slightly, as the thermal trough gets forced back east of the Cascades. Increasing southerly flow aloft will act to destabilize the very warm air mass over Oregon and could lead to impressive thunderstorm development Sunday afternoon and evening...especially over the southern half of the state. Progressively cooler temperatures are likely next week, as the offshore upper-level trough slowly approaches the coastline. Increasing south-southeasterly flow aloft will lead to more widespread shower and thundershower activity across Oregon...including over the Willamette Valley. The surface thermal trough will shift into eastern Oregon by Monday, and possibly as far east as Idaho on Tuesday..allowing stronger onshore flow to initiate a cooling trend statewide. There are big differnces in the long-range computer models for the middle of next week, with some bringing the upper-level trough onshore and others leaving it offshore. My forecast reflects the former solutions but may need to be updated, towards warmer and drier conditions, if the upper-level low-pressure area ends up staying offshore. Tomorrow (01 Aug): Sunny and Very warm. T-storms over the Cascades in the Afternoon. 59/95 Sun (02 Aug): Becoming Parly Cloudy. Chance of T-Storms...Mainly South. 60/91 Mon (03 Aug): Partly to Mostly Cloudy. Chance of Showers or T-Storms. Muggy. 60/88 Tue (04 Aug): Partly to Mostly Cloudy. Chance of Showers and T-Storms. 58/85 Wed (05 Aug): Mostly Cloudy. Chance of Showers and T-Storms. Cooler 56/78 Thu (06 Aug): Mostly Cloudy. Chance of Showers. 53/77 Fri (07 Aug): Morning Clouds...Partly Sunny. 52/80 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Jul 31 12:09:47 2009 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 31 Jul 2009 14:09:47 -0500 Subject: [willamette-fcst] Forecast - Friday, July 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. NOON UPDATE Issued: Friday, July 31st, 2009 at 12:00pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The early morning sounding over Salem this morning showed a few degrees of cooling below 6000 feet, compared to Thursday morning, due to a weak influx of marine air. However, the impressive upper-level ridge, that has been parked over the Pacific Northwest all week, is forecast to strengthen slightly over Oregon today. That will warm the air aloft and anchor the surface thermal trough near the crest of the Cascades...keeping mixing heights low and not allowing for eastward evacuation of air out of the Willamette Valley. Under sunny skies, midday temperatures were quite uniform across the Willamette Valley...mostly in the mid 70s. Morning low clouds and fog were clearing from the coastline, where temperatures had warmed into the upper 50s and low 60s. The warmest conditions were over central, eastern, and southwestern Oregon, where temperatures were already well into the 80s. Daytime heating and mid-level instability will likely fuel at least a few thunderstorms near the thermal trough axis, along and just east of the Cascade crest, and southeastern Oregon. Very weak onshore flow west of the Cascades will cap afternoon temperatures in the upper 80s in the southern Willamette Valley and low 90s in the north valley. There is a risk of an evening thunderstorm sneaking into the southern Willamette Valley, with the flow aloft turning more southeasterly. Surface Winds: NW 5-15 this afternoon. Transport Winds: NNW 9 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 32. High Temperature: Salem\'s high temperature today will be near 90. Humidities: Minimum relative humidity will be near 33%. Sunrise/Sunset: Salem sunset tonight: 8:39pm; sunrise tomorrow: 5:58am. Extended Outlook: The upper-level ridge is forecast to build even slightly more over Oregon Saturday, with increasing southeasterly flow aloft over the southern half of the state. That will increase the mid-level moisture and instability over southern Oregon, for an increased threat of afternoon and evening thunderstorm development. In the Willamette Valley, temperatures will likely warm a few degrees from Friday, with the thermal trough trying to build northwestward, into the Portland area. By Sunday, an upper-level low-pressure area will come close enough to the California Coast to shift the upper-level ridge axis is into eastern Oregon. Increasing southeasterly flow aloft will further highten the thunderstorm potential across the entire state. Due to the warmth of the low-level air mass, there is a chance that some of the storms could become quite strong. Willamette Valley temperatures will likely cool slightly, as the thermal trough gets forced back east of the Cascades. Progressively cooler temperatures are likely next week, as the offshore upper-level trough slowly approaches the coastline. Increasing south-southeasterly flow aloft will lead to more widespread shower and thundershower activity across Oregon...including over the Willamette Valley. Again, some of the storms could be quite strong. Due to the dry conditions, this pattern has the potential to start many wildfires across the state. The surface thermal trough will shift into eastern Oregon by Monday, and possibly as far east as Idaho by Tuesday..allowing stronger onshore flow to initiate a cooling trend statewide. There are big differnces in the long-range computer models for the middle of next week, with some bringing the upper-level low-pressure system onshore and others leaving it offshore. My forecast reflects it coming onshore about Tuesday and Wednesday of next week, followed by a drier more westerly flow aloft late next week. Tomorrow (01 Aug): Sunny and Very warm. T-storms over the Cascades in the Afternoon. 59/95 Sun (02 Aug): Becoming Parly Cloudy. Chance of T-Storms...Mainly South. 60/91 Mon (03 Aug): Partly to Mostly Cloudy. Chance of Showers or T-Storms. Muggy. 60/88 Tue (04 Aug): Partly to Mostly Cloudy. Chance of Showers and T-Storms. 58/85 Wed (05 Aug): Mostly Cloudy. Chance of Showers and T-Storms. Cooler 56/78 Thu (06 Aug): Mostly Cloudy. Chance of Showers. 53/77 Fri (07 Aug): Morning Clouds...Partly Sunny. 52/80 ODA Meteorologist weather at oda.state.or.us