From willamette-fcst at listsmart.osl.state.or.us Wed Oct 1 08:02:07 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 01 Oct 2008 10:02:07 -0500 Subject: [willamette-fcst] Forecast - Wednesday, October 1st, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, October 1st, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 5:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The strong upper-level ridge of high pressure over the Pacific Northwest will continue to move east today with an increasing south-southeasterly flow aloft sending mainly middle and high clouds over Western Oregon today. The Salem sounding this morning was very similar to Tuesday morning, so temperatures should climb to near 80 degrees in the valley again this afternoon. Satellite imagery showed a low pressure center about 500 miles off the Northern California Coast with a band of clouds circulating around it offshore. Some middle and high clouds were already spreading across Western Oregon and should continue to increase during the day. As this system slowly moves closer to the coastline, the southerly flow aloft will increase this afternoon. The ODA surface analysis showed surface thermal trough has weakened over the Willamette Valley this morning and is forecast to further weaken today with light southerly gradients expected across the valley this afternoon. Slight cooling aloft will combine with daytime heating to lift mixing heights to near 3500 feet by late this afternoon. Field burning is finished for the season in the Southern Willamette Valley. There may be limited open burning, in the north valley, later this afternoon, if transport winds are not too southerly. With rain forecast for Thursday and beyond, today will likely be the last field-burning opportunity for this season. Surface Winds: S 5 this morning, SSW 5-10 this afternoon. Transport Winds: S 5 this morning, SSW 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 80. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 36%. Sunrise/Sunset: Salem sunset tonight: 6:52pm; sunrise tomorrow: 7:12am. Extended Outlook: The first in a series of weather systems is forecast to come onshore early Thursday with rain likely by Thursday afternoon across the Willamette Valley. A more potent system is forecast to come onshore late Friday with heavier rain and perhaps strong southerly winds...especially along the coast. Rain will turn to showers Saturday with total rainfal amounts possibly exceeding one inch in the valley. A transitory ridge of high pressure may bring some drying Sunday and Monday, ahead of the next rain-maker on Tuesday. Another ridge of high pressure may dry things out for at least a couple of days beginning Wednesday of next week. Tomorrow (02 Oct): Cloudy and Much Cooler. Light Rain Likely by Afternoon. 55/66 Fri (03 Oct): Mostly Cloudy. Increasing Rain and Wind Late. 52/66 Sat (04 Oct): Rain Turning to Showers and Blustery. 51/63 Sun (05 Oct): Mostly Cloudy. Chance of Light Rain. 49/64 Mon (06 Oct): Mostly Cloudy. 47/69 Tue (07 Oct): Light Rain Likely. 49/64 Wed (08 Oct): Partly Sunny. 45/68 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Oct 2 08:04:39 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 02 Oct 2008 10:04:39 -0500 Subject: [willamette-fcst] Forecast - Thursday, October 2nd, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, October 2nd, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 8:00am until 5:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed from 12:00pm until 5:00pm. Weather Discussion: The early-autumn dry and warm spell was broken overnight, as the first in a series of Pacific Storms moved onshore. The first of several bands of showers rolled nrothward across the Willamette Valley overnight. National Weather Servie and CoCORaHS reports indicate that only a couple hundredths of an inch fell over most of the valley with the greatest totals on the west side of the valley in Benton and Polk Counties. It is possible that some fields in Eastern Marion County have received little to no rain so far. Doppler radar was showing another area of showers extending from the central Coast to near Eugene, moving north up mainly the west side of the Willamette Valley at mid-morning. Surface reports confirm areas of light rain raeching the valley floor, but amounts have generally been only a few hundredths of an inch. The cold front and associated upper-level trough from this first system were still offshore this morning and are forecast to weaken as they move inland late today. That will increase the light shower acticity over Western Oregon with most of the valley likely getting at least a few hundredths of an inch of rain. The Salem sounding from late Wednesday afternoon showed a strong temperature inversion from 1500 feet to 3500 feet, but significant cooling aloft overnight had eliminated it by this morning. Continued cooling aloft should raise mixing heights to around 3500 feet by mid-afternoon with forecast south-southwesterly transport winds. In the unlikely event that any north-valley fields should stay dry, ventilation conditions may allow for open burning this afternoon. We will continue to monitor the rainfall coverage and transport winds today. The cloudy and showery and conditions will finally cool temperatures below normal across Western Oregon today with valley highs only climbing into the mid 60s. The showers should taper off tonight, as the weak upper-level trough moves east of the region. Surface Winds: SSE 3-8 this morning, SSW 7-12 this afternoon. Transport Winds: SSW 10 this morning, SW 16 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3800 feet. Ventilation index 61. High Temperature: Salem\'s high temperature today will be near 66. Humidities: Minimum relative humidity will be near 65%. Sunrise/Sunset: Salem sunset tonight: 6:50pm; sunrise tomorrow: 7:13am. Extended Outlook: Things will briefly dry out early Friday, ahead of a very impressive weather system forecast to bring increasing rain to Western Oregon Friday afternoon. The low pressure center with this strom is forecat to become quite strong and may track close enough to the coastline to bring strong southerly winds to the coastal strip Friday night, along with locally heavy rain to much of Western Oregon.night and Saturday. This strom has the potential, depending on it\'s track, to bring damaging winds to the coast by early Saturday morning. It will likely turn blustery in the Willamette Valley Saturday with continued showers. Total rainfall amounts from this system could exceed one inch in the Willamette Valley, between midday Friday and Saturday night. The showers and winds are forecast to taper off Saturday night, as the low pressure system weakens and moves north to near Vancouver Island, British Columbia. A transitory ridge of high pressure is forecast to bring some drying Sunday with the next system now slated to come onshore late Monday. That system may create a burning opportunity, Monday afternoon, in the unlikely event that fields are dry enough. The cold front is forecast to come onshore early Tuesday with a cool upper-level trough bringing showers to the region through early Wednesday. A ridge of high pressure is forecast to dry things out Thursday. The long-range computer models are showing a stronger ridge of high pressure building over the Pacific Northwest next weekend, which could bring a more prolonged period of dry and warmer weather. Tomorrow (03 Oct): Mostly Cloudy. Increasing Rain and Wind Late. Wind: SSE 10-20. 52/66 Sat (04 Oct): Rain Turning to Showers and Blustery...Decreasing Late. 54/63 Sun (05 Oct): Mostly Cloudy. Slight Chance of a Shower. 48/65 Mon (06 Oct): Mostly Cloudy. Chance of Rain Late. 46/68 Tue (07 Oct): Light Rain Turning to Showers. 51/60 Wed (08 Oct): Decreasing Showers. 45/62 Thu (09 Oct): Partly Sunny. 42/67 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Oct 3 08:04:29 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 03 Oct 2008 10:04:29 -0500 Subject: [willamette-fcst] Forecast - Friday, October 3rd, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, October 3rd, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 8:00am until 5:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The first in a series of Pacific storms brought an end to the recent dry and warm spell with about one-tenth of an inch of rain falling across much of the Willamette Valley in the 24-hour period ending at 5am today. Areas of few light rain were falling this morning across Western Oregon, in advance of a very impressive weather system forecast to bring increasing rain and wind to the region later today. A rapidly intensifying low-pressure center was about 500 miles off the Central Oregon Coast this morning and is forecast to track close enough to the coastline to bring strong southerly winds to the coastal strip beginning about mid-afternoon today. This system has also entrained tropical moisture and may bring close to an inch of rain to the Willamette Valley between now and Saturday afternoon, with greater amounts along the coast and in the coastal range. Satellite imagery showed a solid and developing cloud-shield spreading over Washington and Oregon and extending more than 200 miles offshore. Doppler radar showed a band of rain moving northward over the Northern Willamette Valley with some breaks in the steady precipitation over the south valley and SW Oregon. There will likely be some let-up in the rain later this morning, before it increases again later this afternoon. Even with some rain showers, high tempertures climbed into the low 70s across most of the Willamette Valley Thursday. The Salem sounding this morning showed considerable cooling, below 10,000 feet, compared with Thursday afternoon, so temperatures should not make it out of the 60s today. Some warming aloft is forecast this aftenoon, ahead of the approaching storm, so mixing heights will stay below 3000 feet today. Conditions are too damp for burning. The first significant cold front of autumn is forecast to move across Western Oregon overnight, with locally heavy rain and windy conditions. South winds could gust to near 60 mph along the coast late today and tonight and to near 35 mph in the Willamette Valley Saturday morning. Steady rain will turn to showers by Saturday afternoon, and the brisk southerly winds will slowly decrease. Surface Winds: SE 5-15 this morning, SE 10-20 this afternoon. Transport Winds: SSE 10 this morning, S 20 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2500 feet. Ventilation index 50. High Temperature: Salem\'s high temperature today will be near 66. Humidities: Minimum relative humidity will be near 70%. Sunrise/Sunset: Salem sunset tonight: 6:48pm; sunrise tomorrow: 7:15am. Extended Outlook: A transitory ridge of high pressure is forecast to bring some drying Sunday. There are already differences in the computer model forecasts, by Monday, regarding the timing of the next weather system. It is forecast to come onshore sometime between Monday morning and Monday evening. If it holds off until late in the day, it could create favorable winds for burning, but fields will likely be too damp from the weekend rains. A cool upper-level trough is forecast to bring showers to the region through early Wednesday. All of the computer models are forecasting some drying around Thursday of next week with a strong ridge building somewhere near the west coast by next weekend. If that ridge builds directly over the Pacific Northwest, damp fields would have a chance to dry enough, for possible burning, ahead of storms slated to come onshore the following week. Tomorrow (04 Oct): Showers and Blustery. Wind: S 15-25 G35..Decreasing Late. 54/63 Sun (05 Oct): Mostly Cloudy. Slight Chance of a Shower. 48/65 Mon (06 Oct): Mostly Cloudy. Chance of Rain Late. 46/68 Tue (07 Oct): Light Rain Turning to Showers. 50/63 Wed (08 Oct): Decreasing Showers. 45/62 Thu (09 Oct): Partly Sunny. 42/67 Fri (10 Oct): Partly Sunny. 42/67 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Oct 6 07:54:23 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 06 Oct 2008 09:54:23 -0500 Subject: [willamette-fcst] Forecast - Monday, October 6th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, October 6th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 10:00am until 4:30pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed from 10:00am until 4:30pm. Weather Discussion: Southern Willamette Valley field burning is done for the season. South-southwesterly transport winds, ahead of an approaching cold front, will make for good ventilation conditions over the Willamette Valley this afternoon. However, damp field conditions makes burning of north-valley fields highly unlikely today. A fairly strong early season storm brought rain and wind to Western Oregon over the weekend with high temperatures only in the low 60s (about 10 degrees below normal). The north valley generally received a total of one-half to one inch of rain Friday through Saturday, while the south valley was soaked with three-quarters to one and one-half inches of rain. Southerly wind gusts up to 30 mph followed the cold front Saturday morning across the Willamette Valley with gusts to near 50 mph along the northern and central coast. A weak warm front kept skies gray Sunday, with very light rain across Western Oregon. Additional rainfall amounts were generally less than one-tenth of an inch. Doppler radar was showing a decrease in the light rainfall this mornining across NW Oregon. There were even a few patches of blue sky showing up over Western Oregon. Clouds kept temperatures mild overnight with minimums generally in the mid 50s. Today will be a break day between storms with most of the Willamette Valley seeing at least a little sunshine this afternoon. Temperatures will warm close to normal with highs in the mid to upper 60s. The ODA surface analysis showed light southerly gradients over the Willemette Valley this morning, with a weak warm front pushing northward across Western Washington. Satellite imagery showed the next cold front about 500 miles off the Washington and Northern Oregon Coast. It is forecast to spread more rain onto the coast tonight and across the Willamette Valley overnight. Rainfall amounts are expected to be significantly less with this system compared with the one that came onshore Friday night. The Willamette Valley is forecast to get between one-tenth and one-third of an inch by midday Tuesday. Surface Winds: S 5-15 this morning, S 5-15 this afternoon. Transport Winds: SSW 15 this morning, SSW 18 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 63. High Temperature: Salem\'s high temperature today will be near 67. Humidities: Minimum relative humidity will be near 68%. Sunrise/Sunset: Salem sunset tonight: 6:42pm; sunrise tomorrow: 7:18am. Extended Outlook: A westerly flow aloft will keep a lot of clouds and a chance of showers across Western Oregon Tuesday afternoon through Wednesday, with the best chance for showers in the Western Cascade Foothills of the north valley. High temperatures should cool a couple of degrees each day. A fairly dry but cool system is forecast to drop, from the Gulf of Alaska, into the region Thursday, bringing an increased chance of showers and the lowest snow levels so far this autumn. All of the loong-range models are forcasting a strong upper-level ridge of high pressure to build over the west coast, beginning Friday, for what could be several days of dry weather. That would give damp fields a chance to dry and set up a potential burning opportunity next week. Tomorrow (07 Oct): Light Rain Turning to Showers with Partial Clearing. 54/63 Wed (08 Oct): Mostly Cloudy. Chance of Light Showers...Mainly near the Mountains. 41/61 Thu (09 Oct): Increasing Chance of Showers. Snow Level Dropping to 4000 feet. 39/59 Fri (10 Oct): Partly Sunny. 37/65 Sat (11 Oct): Areas of AM Fog...Partly Cloudy in the Afternoon. 36/66 Sun (12 Oct): Areas of AM Fog...Mainly South. Mostly Sunny. 40/69 Mon (13 Oct): Patchy AM Fog. Increasing Clouds Late. 42/66 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Oct 7 08:02:52 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 07 Oct 2008 10:02:52 -0500 Subject: [willamette-fcst] Forecast - Tuesday, October 7th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Tuesday, October 7th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from now until 5:00pm. Preparatory burning is not allowed. Propane flaming is not allowed. Straw stack burning is allowed, for dry stacks, from now until 5:00pm. Weather Discussion: A weak cold front swept across Western Oregon overnight...dropping about one-tenth to one-third of an inch. The heavier amounts were in the Coast Range and Cascades. Most of the Willamette Valley received about one-tenth of an inch. Mostly cloudy skies held temperatures up overnight with morning minimums staying in the low to mid 50s. The cold front had moved east of the Cascades be mid-morning with a cool westerly flow aloft continuing to circuate a few showers across Western Oregon. Doppler radar showed scattered light showers, moving from WNW to ESE, across Western Washington and NW Oregon. There was some enhancement of the showers, as they bumped up against the Cascades. The Salem sounding this morning showed considerable cooling aloft with the freezing level at 9300 feet. Futher cooling aloft is forecast today, so surface temperatures will struggle into the low 60s this afternoon. High mixing heights and northwesterly transport winds will make for good ventilation conditions for stack burning today, but fields will likely be too damp for open burning. Surface Winds: WSW 5-12 this morning, NW 5-15 this afternoon. Transport Winds: W 10 this morning, NW 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 63. Humidities: Minimum relative humidity will be near 58%. Sunrise/Sunset: Salem sunset tonight: 6:40pm; sunrise tomorrow: 7:20am. Extended Outlook: Showers should taper off Wednesday with continued cool onshore flow. Ventilation conditions will remain good over Western Oregon. A cold upper-level trough is forecast to drop, from the Gulf of Alaska, into the region Thursday. That will increase the showers over Western Oregon with most of the Willamette Valley likely picking up another one-tenth of an inch of rain with locally greater amounts...especially in the north valley near the Cascade Foothills. Snow levels will drop the near or below 4000 feet by Thursday afternoon. The Northern Cascade Mountain Passes will likely get their first snowfall of this season. A strong upper-level ridge of high pressure is still forecast to build over the west coast, beginning Friday, for what should be several days of dry weather. Offshore flow may develop over the weekend, which will aid in the drying of damp fields. How long the protective ridge of high pressure will last is in question, but the latest guidance is suggesting a transition back to a damp westerly flow during the first half of next week. That transition may present a late-season burning opportunity, if fields are dry enough. Tomorrow (08 Oct): Mostly Cloudy. Chance of Showers...Mainly North. 41/61 Thu (09 Oct): Increasing Showers and Very Cool. Snow Level Dropping to 4000 feet. 39/56 Fri (10 Oct): Showers Ending...Becoming Partly Sunny. Continued Cool. 37/59 Sat (11 Oct): Chilly Start with areas of AM Fog...Becoming Mostly Sunny. 35/62 Sun (12 Oct): Areas of AM Fog...Mainly South...Sunny. 38/65 Mon (13 Oct): Mostly Sunny. Increasing Clouds Late. 41/67 Tue (14 Oct): Mostly Cloudy. Chance of Rain. 43/64 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Oct 8 08:04:28 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 08 Oct 2008 10:04:28 -0500 Subject: [willamette-fcst] Forecast - Wednesday, October 8th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, October 8th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The flow aloft became more northwesterly overnight with further drying and cooling. The Salem sounding this morning measured the freezing level at just 5900 feet. Winds had become northeasterly below 3000 feet. Clearing skies and cold air aloft allowed Willamette Valley temperatures to drop into the 30s with areas of fog this morning. McMinnville, Salem, Corvallis, and Eugene all dipped to at least 36 degrees and Hillsboro 35. The ODA surface analysis showed high pressure over Western Washington and Western Oregon with light winds in the Willamette Valley. Satelllite water vapor imagery showed a relatively dry slot, in the northwesterly flow aloft, over Western Oregon this morning, so that helps to explain the lack of shower activity and mostly clear skies above the areas of fog. The flow aloft is forecast to turn more westerly by late this afternoon, and begin to moisten back up, so we should see at least some convective clouds this afternoon. There is a slight chance of a mountain shower. Satellite imagery showed the main area of showers, from the next upstream weather system, moving down the British Columbia Coastline, to near Vancouver Island, at mid-morning. It will not likely make it to Oregon until tonight. Ahead of that today, even with some sunshine, colder air aloft will keep valley temperatures from climbing out of the low 60s. Forecast northerly transport winds and damp field conditions makes open burning of remaining north valley fileds highly unikely this afternoon. Surface Winds: N 5 this morning, N 5-15 this afternoon. Transport Winds: NE 10 this morning, N 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5000 feet. Ventilation index 60. High Temperature: Salem\'s high temperature today will be near 62. Humidities: Relative humidity drops to 50% by 1pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 6:39pm; sunrise tomorrow: 7:21am. Extended Outlook: A cold upper-level trough is forecast to move over the region Thursday. That will turn the low-level flow onshore again and increase the showers over Western Oregon. Most of the Willamette Valley will likely pick up one-tenth to one-quarter of an inch of rain with locally greater amounts...especially in near the Cascade Foothills. Snow levels will drop to near 3000 feet Thursday, which would bring the first sticking snow of the season to the Oregon Cascade Mountain Passes. The flow aloft is forecast to turn sharply northerly and dry out Friday. The cold and dry air mass could lead to near record-cold low temperatures, and a possible early season frost, for the Willamette Valley Friday night/Saturday morning. A strong upper-level ridge of high pressure will build over the west coast Saturday and Sunday with warming aloft promoting moderating temperatures but also areas of morning fog. A weak warm front may bring some high clouds to the region late Saurday and Sunday, but it does not appear strong enough to produce rain. It appears that the ridge will hold through at least next Monday. The ridge is forecast to slowly break down, with increasing westerly flow aloft, next week. Depending on the timing of the first weather system to move onshore, it may provide a burning opportunity for dry fields. The most likely time for that appears to be Tuesday. Thu (09 Oct): Increasing Showers and Very Cool. Snow Level Dropping to 4000 feet. 38/56 Fri (10 Oct): Showers Ending...Becoming Partly Sunny. Continued Cool. 37/58 Sat (11 Oct): Possible Record Cold Start...Mostly Sunny and Cool Afternoon. 31/60 Sun (12 Oct): Areas of AM Fog...Mainly South...Mostly Sunny. 36/65 Mon (13 Oct): Mostly Sunny. Possible Increasing Clouds Late. 40/67 Tue (14 Oct): Increasing Clouds. 43/67 Wed (15 Oct): Cloudy. Chance of Light Rain. 46/62 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Oct 10 08:03:34 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 10 Oct 2008 10:03:34 -0500 Subject: [willamette-fcst] Forecast - Friday, October 10th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, October 10th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 10:00am until 4:30pm. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A cold upper-level trough brought cool showery conditions to Western Oregon Thursday afternoon with the first significant snowfall of the season to the Cascades. The Willamette Valley had locally heavy showers, some with hail, and generally received from one-tenth to one-quarter of an inch of rain. Greater amounts fell in some of the Cascade foothills. Valley temperatures only managed to climb into the mid 50s...about 10-15 degrees below normal. The Cascade passes picked up a couple of inches of snow with light snow also falling over the Siskiyou Summit in Southern Oregon. The Salem sounding this morning showed very cold air aloft, for this time of the year. The freezing level was measured at just 3500 feet, which puts the snow level at only 2500 feet. The air mass was beginning to dry out, with the upper-level trough sliding south and east of the region. Satellite imagery showed skies beginning to clear over much of Washington and NW Oregon with no shower activity showing up on the Portland Doppler radar. Decreasing shower activity overnight allowed surface temperatures to cool into the mid 30s across much of the Willamette Valley by this morning. Salem and Eugene both dropped to at least 34 degrees. McMinnville and Hillsboro dipped to 35. Corvallis recorded a low this morning of 36 and Aurora had 37. A fair amount of low clouds remained over the Willamette Valley at mid-morning, but there was just enough instability to prevent much fog from forming. Temperatures had only managed to climb into the upper 30s and low 40s. The upper-level trough is forecast continue to move south and east and extend from Idaho through Nevada this afternoon. A cold and drier northeasterly flow aloft will promote slowly clearing skies over Western Oregon. Increasing northerly surface winds will help relative humidities drop to near or below 50%. Valley temperatures will remain well below normal with highs only in the mid 50s. Clearing skies tonight will lead to near record low temperatures for much of Western Oregon Saturday morning. Sections of the Willamette Valley will likely dip to near or slightly below the freezing mark for the first time this autumn. The forecast low temperature, of 31 degrees, for Salem overnight would tie the record low previously set in 1990. Surface Winds: NNW 5-10 this morning, N 10-15 G20 this afternoon. Transport Winds: NNW 6 this morning, NE 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3500 feet. Ventilation index 53. High Temperature: Salem\'s high temperature today will be near 56. Humidities: Relative humidity drops to 50% by 3pm. Minimum relative humidity will be near 47%. Sunrise/Sunset: Salem sunset tonight: 6:35pm; sunrise tomorrow: 7:23am. Extended Outlook: Northerly flow aloft will continue tomorrow, as a strong upper-level ridge of high pressure begins building over the west coast. Warming aloft will moderate temperatures but also lead to temperature inversions Saturday night with areas of fog. A weak warm front may bring some high clouds to the region by Sunday, but it does not appear strong enough to produce rain. Northerly winds will likely prevail through Monday, with a weak weather system turning the flow onshore Tuesday and creating a potential burning opportunity Tuesday afternoon. That system may not be strong enough to produce much rain, if any, which would open to door for possible future burning opportunities, if necessary. The computer forecast models are now indicating that a ridge of high pressure may rebuild over the west coast Wednesday, with transport winds turning northerly again. It may take until the following weekend, or longer, for strong enough systems to bring much rain back to Western Oregon. That would be consistent with the ODA Seasonal Climate Outlook, which predicted a slightly drier than normal October with the usual transition to wet conditions holding off until the second half of the month. The seasonal climate outlook is updated monthly, around the 20th of the month, and is available on the ODA website at http://oregon.gov/ODA/NRD/weather.shtml#Weather_forecasts. Sat (11 Oct): Possible Record Cold Start with Areas AM Fog...Mostly Sunny and Cool. 31/60 Sun (12 Oct): Cold Morning with Areas of AM Fog...Mostly Sunny. 34/63 Mon (13 Oct): Areas of AM Fog...Mostly Sunny. 37/66 Tue (14 Oct): Increasing Clouds. Onshore Flow Developing. 43/63 Wed (15 Oct): Areas of AM Fog. Partly Cloudy. Wind Becoming Northerly. 42/64 Thu (16 Oct): Areas of AM Fog. Partly Cloudy. Continued Light Northerly Winds. 40/66 Fri (17 Oct): Areas of AM Fog. Mostly Sunny. Light North Winds. 42/67 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Oct 13 09:54:21 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 13 Oct 2008 09:54:21 -0700 Subject: [willamette-fcst] Willamette Valley Ag Forecast Message-ID: Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, October 13th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A cold and dry northerly flow aloft led to record low temperatures across sections of Western Oregon Saturday morning. Astoria, McMinnville, and Eugene all recorded new daily record cold minimums and Salem missed a long-standing record by just one degree. Saturday Morning Record Minimums: Astoria 32 degrees...old record 33 set in 1969 McMinnville 28 degrees...old record 29 set in 1924 Salem 31 degrees...record 30 set in 1919 and 1894 Eugene 28 degrees...old record 30 set in 2002 Sunshine warmed temperatures into the low 60s Saturday afternoon with north winds helping to dry damp fields. As the upper-level ridge built over the region, a weak warm front kept temperatures warmer Sunday morning and brought a few sprinkles to the Northern Willamette Valley. Once again, high temperatures climbed into the low 60s Sunday afternoon. Satellite imagery showed low clouds, associated with another weak warm front, across Western Washington and NW Oregon. Surface observations confirmed areas of light rain across Western Washington and along the Nrothern Oregon Coast, at Astoria. There were no reports of rain in the Willamette Valley as of mid-morning. The warm front may bring a few sprinkles in the extreme north valley before pushing north and the region this afternoon. The Salam sounding this morning showed considerable warming aloft since Sunday. That will keep mixing heights below about 1000 feet until surface temperatures climb to near 60 degrees. Valley temperaturs were only in the upper 40s and low 50s at mid-morning, so mixing heights will stay quite low through early afternoon. Partial clearing and warmer south winds should combine to lift valley temperatures into the mid 60s later this afternoon, with mixing heights climbing to near 3000 feet. Clouds, associated with a cold front, stretched from Vancouver Island, British Columbia southwestward to about 400 miles west of the Northern Oregon Coast this morning. That system will slowly push southeastward today and may improve ventilation conditions enough to allow for open burning of dry north valley fields later this afternoon. We plan to begin pibal readings at 1pm. The cold front will bring a chance of light rain to Western Oregon overnight...mainly north. Total rainfall amounts should be less than one-tenth of an inch with sections of the south valley likely seeing little to no rainfall. Surface Winds: SSE 4-8 this morning, S 4-8 this afternoon. Transport Winds: SW 7 this morning, WSW 7 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3000 feet. Ventilation index 21. High Temperature: Salem\'s high temperature today will be near 65. Humidities: Minimum relative humidity will be near 56%. Sunrise/Sunset: Salem sunset tonight: 6:30pm; sunrise tomorrow: 7:27am. Extended Outlook: A transitory ridge of high pressure is forecast to build over Oregon Tuesday and Wednesday with partial clearing and northerly transport winds. A warm front may bring some sprinkles or very light rain, mainly to the north valley, Thursday. A cold front is forecast to bring a chance of light rain by Friday night. A weak westerly flow is forecast over the weekend with a stronger system moving onshore Sunday night. Tomorrow (14 Oct): Chance of Light Rain Early...Becoming Partly Cloudy. 46/63 Wed (15 Oct): Areas of AM Fog. Partly Sunny. 39/60 Thu (16 Oct): Mostly Cloudy/Foggy. Chance of Sprinkles...Mainly North. 41/65 Fri (17 Oct): Areas of AM Fog. Increasing Clouds. Chance of Light Rain Late. 45/67 Sat (18 Oct): Mostly Cloudy. Decreasing Chance of Showers. 46/62 Sun (19 Oct): Increasing Clouds. Chance of Rain Late. 43/65 Mon (20 Oct): Chance of Rain. 44/60 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Oct 14 08:07:12 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 14 Oct 2008 10:07:12 -0500 Subject: [willamette-fcst] Forecast - Tuesday, October 14th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Tuesday, October 14th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: Mixing heights near 4000 feet and westsouthwesterly transport winds allowed for the open burning of remaining Northern Willamette Valley fields Monday afternoon. Although mixing heights will be fairly high again today, conditions are not favorable for stack burning, due to northeasterly transport winds. A very weak cold front moved across Western Oregon early this morning with only trace amounts of rain in the north valley. The north coast did pick up a few hundredths of an inch of rain. The frontal zone had pushed east of the Cascades, by mid-morning, and stretched from NE to SW Oregon. It is mostly a cloud-maker and will continue to weaken, as it pushes into Idaho, today. The ODA surface analysis showed high pressure building into Western Oregon with surface winds in the Willamette Valley becoming northerly. Satellite imagery showed areas of low clouds but also a fair amount of clearing across the valley. Skies should be partly sunny today across Western Oregon, with a lack of any storm activity in a westerly flow aloft. The Salem sounding this morning showed cooling aloft, since Monday afternoon, so high temperatures will be about 5 degrees cooler today, even with some sunshine. The cool air mass and clearing skies will allow temperatures to drop well into the 30s, across the Valley, overnight. It is not impossible that isolated pockets could drop to the freezing mark, but widespread freezing temperatures are not expected. Surface Winds: N 5-12 this morning, N 7-14 this afternoon. Transport Winds: NE 10 this morning, NNE 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 3600 feet. Ventilation index 36. High Temperature: Salem\'s high temperature today will be near 64. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 46%. Sunrise/Sunset: Salem sunset tonight: 6:28pm; sunrise tomorrow: 7:28am. Extended Outlook: A transitory ridge of high pressure is forecast to build over Oregon Wednesday morning with areas of early morning fog givning way to increasing high clouds in the afternoon. Low-level temperatures inversions will increase with surface temperatures likely cooling a few degrees from Tuesday. A warm front will spread considerable clouds over the region Wednesday night and Thursday with a chance of very light rain...mainly in the north valley. Southeasterly winds will mix the air near the surface and likely warm temperatures a few degrees from Wednesday. A little clearing and slightly warmer temperatures are likely Friday, ahead of a cold front forecast to bring a chance of light rain by Friday night. A weak westerly flow is forecast Saturda with an increasing southwesterly flow aloft Sunday. A stronger cold front is forecast to come onshore Sunday night and Monday. Tomorrow (15 Oct): Areas of AM Fog. Increasing High Clouds. Chance of Light Rain. 35/61 Thu (16 Oct): Cloudy. Chance of Sprinkles/Light Rain...Mainly North. 41/64 Fri (17 Oct): Increasing Clouds. Chance of Light Rain Late. 47/67 Sat (18 Oct): Becoming Partly Sunny. 46/65 Sun (19 Oct): Increasing High Clouds and Mild. Chance of Rain Late. 44/67 Mon (20 Oct): Rain Likely. Snow Level Dropping to near 4000 Feet. 47/59 Tue (21 Oct): Showers Ending...Becoming Partly Sunny. 46/62 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Oct 15 07:43:13 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 15 Oct 2008 09:43:13 -0500 Subject: [willamette-fcst] Forecast - Wednesday, October 15th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. ...There will be no noon update today. The next update will be issued at 9:00am tomorrow... Issued: Wednesday, October 15th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A building ridge of high pressure cleared skies Tuesday evening and allowed Willamette Valley temperatures to drop to near the freezing mark this morning, with areas of dense fog forming. Hillsboro, McMinnville, and Corvallis all dropped to 30 degrees. Dense fog helped Eugene stay above freezing at 33. Salem dipped to 34 and Aurora 35. Warming aloft and cool surface temperatures will maintain a low-level temperature inversion over the valley today, so mixing heights should remain at or below 2000 feet. The ODA surface analysis showed high pressure over Western Oregon with little weak pressure gradients over the Willamette Valley. Transport winds will be light and variable, making for poor ventilation conditions. Satellite imagery showed high clouds already beginning to spread over Western Oregon, in response to a weak warm front well offshore. Valley fog will be slow to give way to increasing high clouds today, so high temperatures will struggle into the mid to upper 50s (about 5-10 degrees below normal). The warm front could spread some light rain onto the north coast by late this afternoon with a little rain possible in the Northern Willamette Valley tonight and Thursday. More clouds will keep temperatures warmer tonight with minimums generally in the low 40s. Surface Winds: Var 0-4 this morning, Var 4 this afternoon. Transport Winds: NE 5 this morning, Var 4 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2000 feet. Ventilation index 10. High Temperature: Salem\'s high temperature today will be near 57. Humidities: Minimum relative humidity will be near 50%. Sunrise/Sunset: Salem sunset tonight: 6:26pm; sunrise tomorrow: 7:30am. Extended Outlook: A warm front will bring cloudy skies to the region Thursday with a chance of sprinkles or very light rain in the north valley. Increasing southeasterly winds will help stir the air, break up the fog, and warm temperatures into the low to mid 60s. The warm front is forecast to push north of the region Friday with southerly winds warming temperatures into the mid to upper 60s. A cold front is forecast to bring a chance of light rain by Friday night...mainly to the north valley. Ahead of the cold front, there may be a burning opportunity, Friday afternoon, for remaining fields. A weak upper-level trough will maintain onshore flow Saturday with a transitory upper-level ridge building over the west coast Sunday. Increasing southwesterly flow aloft will send a stronger cold front onshore Monday. A transitory ridge is forecast for Tuesday with a weak weather system slated for late Wednesday and Thursday. Tomorrow (16 Oct): Cloudy. Chance of Sprinkles/Light Rain...Mainly North. 41/64 Fri (17 Oct): Increasing Clouds. Chance of Light Rain Late. 47/67 Sat (18 Oct): Slight Chance of a Showers Early...Becoming Partly Sunny. 46/65 Sun (19 Oct): Increasing High Clouds and Mild. 45/67 Mon (20 Oct): Rain Developing. Snow Level Dropping to near 4000 Feet Late. 47/59 Tue (21 Oct): Chance of Showers Early...Partly Sunny Afternoon. 45/61 Wed (22 Oct): Increasing Clouds...Chance of Rain Late. 42/64 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Oct 16 08:03:23 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 16 Oct 2008 10:03:23 -0500 Subject: [willamette-fcst] Forecast - Thursday, October 16th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, October 16th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: A warm front brought very light rain to the Willamette Valley overnight with total rainfall amounts ranging from a trace in the south valley to several hundredths of an inch in the north valley. The Stayton area picked up about one-tenth of an inch. The warm front is forecast to slowly move north today with the light rain tapering off by early this afternoon. The Salem sounding this morning showed considerable warming aloft since Wednesday morning, so mixing heights will be held to near or below 2000 feet again today. Low-level southerly winds had increased, in response to the warm front. The ODA surface analysis also showed increased southerly gradients with southerly surface winds of 5-15 mph in the Willamette Valley. Cloudy and windy conditions made for a much warmer overnight period with morning minimums staying near 50 degrees. Skies may partially clear later this afternoon, mainly in the south valley. With the air aloft continuing to warm, even a little sunshine would combine with southerly winds to lift temperatures into the mid to upper 60s. However, where the clouds persist, which is likely in the north valley, temperatures will not likey warm more than the low 60s. Partial clearing tonight should allow temperatures to cool into the mid to upper 40s tonight with areas of fog forming. Surface Winds: S 5-15 this morning, S 5-12 this afternoon. Transport Winds: S 15 this morning, S 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2000 feet. Ventilation index 30. High Temperature: Salem\'s high temperature today will be near 64. Humidities: Minimum relative humidity will be near 60%. Sunrise/Sunset: Salem sunset tonight: 6:25pm; sunrise tomorrow: 7:31am. Extended Outlook: Partial clearing and warm air aloft Friday should help surface temperatures climb into the mid to upper 60s in the north valley and near 70 in the south valley. If surface temperatures become warm enough Friday afternoon, forecast west-southwesterly transport winds may provide adequate ventilation for the burning of remaining dry fields. A weak cold front is forecast to bring a chance of light rain Friday night through Saturday morning...mainly to the north valley. Transport winds are forecast to turn northerly Saturday. A transitory upper-level ridge is forecast to move over the region Sunday. Increasing southwesterly flow aloft will send a stronger cold front onshore Monday. A transitory ridge is forecast for provide a break from the damp weather Tuesday with some afternoon clearing. Another cold front will likely bring more rain late Wednesday and Thursday. Tomorrow (17 Oct): Areas of AM Fog. Increasing Clouds. Chance of Light Rain Late. 47/67 Sat (18 Oct): Chance of Light Rain Early...Partial Afternoon Clearing. 48/63 Sun (19 Oct): Areas of AM Fog. Mostly Sunny in the Afternoon. 45/65 Mon (20 Oct): Rain Developing. Snow Level Dropping to near 4500 Feet Late. 45/59 Tue (21 Oct): Areas of AM Fog...Partly Sunny Afternoon. 42/62 Wed (22 Oct): Increasing Clouds...Chance of Rain by Afternoon. 39/61 Thu (23 Oct): Chance of Showers. 42/59 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Oct 17 08:04:58 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 17 Oct 2008 10:04:58 -0500 Subject: [willamette-fcst] Forecast - Friday, October 17th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, October 17th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is not allowed. Weather Discussion: The warm front that brought very light rain to the Willamette Valley early Thursday moved north, with skies gradually clearing Thursday afternoon and evening. That allowed temperatures to drop into the low to mid 40s overnight with areas of dense fog forming in the Willamette Valley. Visibilities were generally less than one-half mile throughout the valley at mid-morning. The fog should give way to some sunshine this afternoon with increasing high clouds from an approaching cold front. The Salem sounding this morning should significant warming aloft since yesterday with light northerly low-level winds. Warm air aloft will help high temperatures climb to near 70 degrees but also suppress mixing heights again today. The cold front slated to move onshore this evening has slowed down and stretched from Vancouver Island, British Columbia to almost 300 miles off the northern Oregon Coast. A slight delay in the arival of that system may be enough to keep transport winds northerly today, which is not conducive to good ventilation for burning. If the fog burns off quickly enough, and surface temperatures rise to near 70 degrees, mixing heights should climb to near 2500 feet later this afternoon. Northerly transport winds would need to become more westerly to allow for stack or open burning, which is not currently forecast by computer models, due to the slower speed of the approaching cold front. However, a shift to a more westerly transport wind direction is possible, so we plan to begin pibal readings at 11:30 a.m. and will continue to monitor conditions through early this afternoon. Clouds will increase this evening with a chance of sprinkles or very light rain tonight moving into the north valley. The front is forecast to stall and weaken over Western Oregon Saturday for a continued chance of drizzle or very light rain...mainly north. Total rainfall amounts from this system should be less than one-tenth of an inch. Surface Winds: N 3 this morning, N 4-8 this afternoon. Transport Winds: N 5 this morning, N 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2600 feet. Ventilation index 21. High Temperature: Salem\'s high temperature today will be near 70. Humidities: Minimum relative humidity will be near 57%. Sunrise/Sunset: Salem sunset tonight: 6:23pm; sunrise tomorrow: 7:32am. Extended Outlook: A transitory upper-level ridge is forecast to move over the region Sunday. Increasing southwesterly flow aloft will send a stronger weather system onshore Monday through early Tuesday. Total rainfall amounts from this system are forecast to range from one-tenth to more than one-quarter of an inch, with the greatest amounts in the north valley. Another upper-level ridge is forecast for provide a break from the damp weather Tuesday and Wednesday with morning valley fog and afternoon sunshine. A cold front will likely bring more rain Thursday. The long-range models are indication the possibility that a strong ridge of high pressure will build back over the region, beginning Friday, that may bring dry and mild weather well into the following week. Tomorrow (18 Oct): Mostly Cloudy. Decreasing Chance of Sprinkles or very Light Rain. 48/63 Sun (19 Oct): Areas of AM Fog. Mostly Sunny in the Afternoon. 40/65 Mon (20 Oct): Rain Developing. Snow Level Dropping to near 4000 Feet Late. 45/59 Tue (21 Oct): Areas of AM Fog...Mostly Sunny Afternoon. 39/62 Wed (22 Oct): Areas of AM Fog...Mostly Sunny Afternoon. Increasing Clouds Late. 39/66 Thu (23 Oct): Light Rain Likely. 44/59 Fri (24 Oct): Areas of AM Fog. Partly Sunny in the Afternoon. 40/62 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Oct 17 13:59:07 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 17 Oct 2008 15:59:07 -0500 Subject: [willamette-fcst] Forecast - Friday, October 17th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. ...Updated Burn Advisory For Stack Burning... Issued: Friday, October 17th, 2008 at 2:30pm. Burn Advisory: Agricultural burning is not recommended. Preparatory burning is not allowed. Propane flaming is not allowed. Stack burning is allowed, north of a line from Jefferson to Scio, from now until 4:30pm. Stack burning is not allow south of a line from Jefferson to Scio. Weather Discussion: Foggy skies continued to hold valley temperatures in the upper 50s in the southern Willamette Valley at mid-afternoon. Sunshine had warmed north valley temperatures into the mid 60s, which should lift mixing heights above 2000 feet north of a Jefferson to Scio line. Pibals from Salem showed northwesterly winds above 2000 feet, so stack burning is allowed until 4:30pm for the areas mentioned above. Skies should begin to clear in the south valley later this afternoon, but it will be too late for stack burning there. The cold front, originally slated to move into Oregon this evening, has slowed down and was spreading rain only across northwest Washington at mid-afternoon with clouds increasing across extreme northwest Oregon. Clouds will increase this evening with a chance of sprinkles or very light rain moving into the north valley overnight. The front is forecast to slowly weaken and move south, across the Willamette Valley, Saturday morning with a continued chance of drizzle or very light rain. Total rainfall amounts should be less than one-tenth of an inch, so stacks will likely stay dry enough for burning. Surface Winds: Variable 3-6 this afternoon. Transport Winds: N 3-8 south valley...NW 4-8 in the north valley. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2500 feet. Ventilation index 20. High Temperature: Salem\'s high temperature today will be near 68. Humidities: Minimum relative humidity will be near 50%. Sunrise/Sunset: Salem sunset tonight: 6:23pm; sunrise tomorrow: 7:32am. Extended Outlook: A transitory upper-level ridge is forecast to move over the region Sunday. Increasing southwesterly flow aloft will send a stronger weather system onshore Monday through early Tuesday. Total rainfall amounts from this system are forecast to range from one-tenth to more than one-quarter of an inch, with the greatest amounts in the north valley. Another upper-level ridge is forecast for provide a break from the damp weather Tuesday and Wednesday with morning valley fog and afternoon sunshine. A cold front will likely bring more rain by Thursday afternoon. The long-range models are indicating the possibility of a strong ridge of high pressure building over the region, beginning Friday, with a prolonged period of mostly dry and mild weather lasting into the following week. Tomorrow (18 Oct): Mostly Cloudy. Decreasing Chance of Sprinkles or very Light Rain. 48/63 Sun (19 Oct): Areas of AM Fog. Mostly Sunny in the Afternoon. 40/65 Mon (20 Oct): Rain Developing. Snow Level Dropping to near 4000 Feet Late. 45/59 Tue (21 Oct): Areas of AM Fog...Mostly Sunny Afternoon. 39/62 Wed (22 Oct): Areas of AM Fog...Mostly Sunny Afternoon. Increasing Clouds Late. 39/66 Thu (23 Oct): Light Rain Likely. 44/59 Fri (24 Oct): Areas of AM Fog. Partly Sunny in the Afternoon. 40/62 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Mon Oct 20 08:03:31 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Mon, 20 Oct 2008 10:03:31 -0500 Subject: [willamette-fcst] Forecast - Monday, October 20th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Monday, October 20th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 8:00am until 4:30pm. Straw stack burning is allowed from 8:00am until 4:30pm. Weather Discussion: A weakening frontal system brought some sprinkles to the Willamette Valley Saturday morning, with many areas not even getting measurable rain. Aurora, Salem, and Corvallis all received just one-hundredth of an inch. A transitory ridge brought a return of stagnant weather conditions Sunday with areas dense morning valley fog. Clouds began increasing late in the day, Sunday, in reponse to an approaching cold front. That helped lift the fog from the valley Sunday afternoon, with a few sprinkles moving in the region by early this morning. The ODA surface analysis showed a cold front moving onto the Washington and Oregon coastlines at mid-morning. Doppler radar showed a band of light rain extending from Western Washington through the northern Willamette Valley with the back edge of the precipitation already making it the the coast range. Surface reports indicated light rain from Portland southward, through Salem, with the south edge of the rainfall, on radar, pushing south to Eugene. Temperatures were near 50 degrees with southerly winds between 10 and 20 mph. The cold front, and associated steady light rain, should quickly move east of the Willamette Valley by this afternoon. Cooling aloft will help mixning heights climb to near 5000 feet this afternoon with morning southerly transport winds becoming west-southwesterly. However, the main pool of cold air, in the wake of this system, will come onshore north of Oregon, so only a few showers are likely in the Willamette Valley this afternoon and evening. Snow levels, in the northern Cascades, will drop to near 4000 feet by this evening with a little snow possible over the passes. Snow levels may remain higher than pass levels in the southern Cascades. Breezy south winds, this morning, will turn more westerly this afternoon and taper off by this evening. With cooler air aloft moving over the region this afternon, high temperatures will have a tough time making it over 60 degrees. Partial clearing tonight will help temperatures drop into the upper 30s across most of the valley, with areas of fog forming by Tuesday morning. Surface Winds: S 10-20 this morning, W 7-15 this afternoon. Transport Winds: S 20 this morning, WSW 15 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 5000 feet. Ventilation index 100. High Temperature: Salem\'s high temperature today will be near 59. Humidities: Minimum relative humidity will be near 62%. Sunrise/Sunset: Salem sunset tonight: 6:18pm; sunrise tomorrow: 7:36am. Extended Outlook: Another upper-level ridge is forecast to build over the region Tuesday. Areas of moring fog could be locally dense...especially in the south valley. A weak warm front will likely spread some middle and high clouds across NW Oregon during the day. The upper-level rideg will amplify on Wednesday with increasing offshore flow clearing the fog from the valleys and mixing warmer air aloft down to the surface. That could push afternoon temperatures into the 70s, which would be at least 10 degrees above normal. This very warm forecast to supported by the top seasonal climate analog year of 1929, which also had very warm weather at this time. In fact, Salem\'s record high this Wednesday, of 83 degrees, was set in 1929. A weak cold front will bring a chance of light rain Thursday afternoon...mainly to the north valley. The long-range models are all showing a strong ridge of high pressure building over the region, beginning Friday, with a prolonged period of dry and very mild weather lasting well into the following week. Offshore flow may develop enough by next Monday for valley temperatures to, once again, climb into the low 70s. Tomorrow (21 Oct): Areas of AM Fog...Mostly Sunny Afternoon. 39/62 Wed (22 Oct): Patchy AM Fog South...Otherwise Sunny and Very Mild. 37/72 Thu (23 Oct): Chance of Light Rain...Mainly North. 45/61 Fri (24 Oct): Areas of AM Fog. Partly Sunny in the Afternoon. 39/62 Sat (25 Oct): Areas of AM Fog. Partly Sunny in the Afternoon. 40/64 Sun (26 Oct): Areas of AM Fog. Mostly Sunny in the Afternoon. 41/66 Mon (27 Oct): Areas of AM Fog...Mainly South. Sunny and Mild in the Afternoon. 41/71 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Tue Oct 21 07:52:13 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Tue, 21 Oct 2008 09:52:13 -0500 Subject: [willamette-fcst] Forecast - Tuesday, October 21st, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Tuesday, October 21st, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Stack burning is not allowed. Weather Discussion: The cold front that dropped about one-tenth of an inch of rain across the Willamette Valley Monday had pushed east into Wyoming this morning. Instability showers ended late last night with partial clearing and cool air aloft allowing temperatures to locally drop to near the freezing mark by early this morning. McMinnville dipped to 31 degrees and Hillsboro hit 33. Salem had a low of 35 degrees, while Corvallis and Eugene bottomed out at 36. Aurora and Portland were warmer with minimums of 37 and 40 respectively. An upper-level ridge was beginning to build over Oregon early this morning with the Salem sounding showing northwesterly flow aloft with considerable warming above 10,000 feet. The stabilizing air mass allowed widespread fog to form in the Willamette Valley this morning with visibilities locally less than one-quarter of a mile. The ODA surface analysis showed high pressure centered over Western Oregon with light pressure gradients. A buiding thermal trough, into southwestern Oregon, will help generate drying northerly winds across the Willamette Valley this afternoon, which will aid in the break-up of the valley fog layer. A weak warm front may spread some high clouds across NW Oregon during the day, otherwise look for fog to give way to mostly sunny skies this afternoon. Valley temperatures will vary, depending on the local duration of the fog. With afternoon sunshine, high temperatures should range from the upper 50s to low 60s. A drier offshore flow will likley keep the fog from being as widespread tonight but will also allow temperatures to drop into the low 30s with areas of frost by Wednesday morning. Surface Winds: Var 0-5 this morning, N 5-10 this afternoon. Transport Winds: Var 4 this morning, NNE 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2000 feet. Ventilation index 20. High Temperature: Salem\'s high temperature today will be near 60. Humidities: Relative humidity drops to 50% by 3pm. Minimum relative humidity will be near 46%. Sunrise/Sunset: Salem sunset tonight: 6:16pm; sunrise tomorrow: 7:38am. Extended Outlook: The upper-level ridge will amplify Wednesday with offshore flow clearing the patchy morning fog from the valleys earlier in the day...allowing for more sunshine. The air aloft will continue to warm and may support surface temperatures locally climbing into the low 70s. A weak cold front will slide north of Oregon Thursday...turning the surface flow onshore and cooling the air aloft. That will knock 5-10 degrees off high temperatures, but this system no longer appears strong enough to bring any rain to the region. Another cold front is forecast to move onshore north of Oregon Friday with continued onshore flow and near-normal temperatures. The long-range models all show a strong ridge of high pressure building over the region this weekend. That will bring a prolonged period of dry and very mild weather into early next week. Offshore flow may develop as soon as Saturday, which would send temperatures well above normal. It is possible that highs could climb above 70 degrees. A cold front may swing close enough to the region to cool temperatures closer to normal about Tuesday. There are considerable differences in the computer models, beginning around the middle of next week, with a return to more damp weather possible. Wed (22 Oct): Cold Start with Patchy AM Fog South...Mainly South. Sunny and Mild. 32/72 Thu (23 Oct): Partly Cloudy. 37/65 Fri (24 Oct): Partly Cloudy. 39/63 Sat (25 Oct): Areas of AM Fog...Mainly South. Mostly Sunny and Mild. 39/68 Sun (26 Oct): Areas of AM Fog...Mainly South. Mostly Sunny and Mild. 42/68 Mon (27 Oct): Areas of AM Fog...Mainly South. Mostly Sunny and Mild. 42/67 Tue (28 Oct): Partly Cloudy. 40/63 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Oct 22 08:04:00 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 22 Oct 2008 10:04:00 -0500 Subject: [willamette-fcst] Forecast - Wednesday, October 22nd, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, October 22nd, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Stack burning is not allowed. Weather Discussion: An upper-level ridge is amplifying over the region this morning. The Salem sounding showed massive warming above 2000 feet, since Teuesday afternoon. There was a strong temperature inversion this morning from about 1000 feet up to 1800 feet. The temperature at the top of the inversion was 57 degrees, while temperatures at the surface were in the low to mid 30s. Normally that would be a classic set up for fog. However, increasing offshore flow is drying the low-level air mass enough to limit fog formation in the Willamette Valey this morning. The ODA surface analysis showed high pressure centered over Eastern Washington with a thermal trough building along the southern Oregon Coast. Strong offshore gradients were producing brisk easterly winds, just above the inversion layer. The easterly winds were dropping off the coast range and busting through the inversion along sections of the coastal strip. Newport was recording gusts over 25 mph this morning with tempertures in the low 50s. Strong east winds had also developed at the western end of the Columbia Gorge. Troutdale was getting gusts to 35 mph this morning and also had temperatures near 50 degrees. Below the inversion, winds were light across most of the the Willamette Valley at mid-morning. Sections of the valley had frost this morning. Skies were generally clear in the north valley, but there were areas of fog in the more sheltered south valley, from Corvallis to Eugene. Visibilities were locally less than one-quarter of a mile. Corvallis was also one of the coldest spots in the valley this morning, recording a minimum of just 28 degrees. Aurora and Hillsboro both dropped to the freezing mark and Salem dipped to 33 degrees. Meanwhile, north winds kept the low-level air mixed, in McMinnville, where the temperature stayed in the upper 30s. Portland also stayed warmer with a low of 38. Visible satellite imagery showed the fog and low clouds in the western valleys from about Corvallis south to Roseburg. The remainder of the state had sunny skies this morning. Valley temperatures were still mostly in the 30s. It was quite cold east of the Cascades with temperatures mostly in the 20s and a few spots in the teens. Burns and Rome both recorded minimums of just 18 degrees. Continued offshore flow today will clear the areas of fog from the southern valleys later this morning and bring sunshine to the entire state. The air aloft will continue to warm and may support surface temperatures locally climbing into the low 70s, if there is enough down-mixing of warm air through the inversion layer. In any case, mixing heights will remain below 2000 feet. A weak cold front will begin to spread some high clouds across northwest Oregon tonight and weaken the offshore flow enough to allow for areas of fog to form in the Willamette Valley. Low temperatures will likely be a few degrees warmer than they were this morning...staying mostly above the freezing mark. Surface Winds: NNE 5-10 this morning, NNE 5-10 this afternoon. Transport Winds: NE 10 this morning, ENE 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 1800 feet. Ventilation index 18. High Temperature: Salem\'s high temperature today will be near 72. Humidities: Relative humidity drops to 50% by 12pm. Minimum relative humidity will be near 26%. Sunrise/Sunset: Salem sunset tonight: 6:15pm; sunrise tomorrow: 7:39am. Extended Outlook: A weak cold front will flatten the ridge of high pressure, as it slides north of Oregon Thursday. The trailing end of the front will bring onshore flow and some clouds into northwest Oregon. That will knock 5-10 degrees off high temperatures, but no rainfall is expected. Another cold front is forecast to do approximately the same thing Friday, with some clouds but no rain expected. The long-range models all show a strong ridge of high pressure building over the region this weekend and lasting through the first half of next week. Offshore flow may develop as soon as Saturday, which would send temperatures well above normal with sunny skies statewide. It is possible that western Oregon highs could approach record warm levels Sunday through Tuesday. The ridge will likely begin to break down about Wednesday of next week with increasing southwesterly flow aloft. A cold front may bring a chance of rain on Thursday with temperatures dropping closer to normal. Tomorrow (23 Oct): Partly Sunny. 37/64 Fri (24 Oct): Partly Sunny. 38/63 Sat (25 Oct): Areas of AM Fog...Mainly South. Mostly Sunny and Mild. 39/68 Sun (26 Oct): Patchy AM Fog...Mainly South. Sunny and Near Record Warmth. 42/74 Mon (27 Oct): Patchy AM Fog...Mainly South. Sunny and Near Record Warmth. 43/74 Tue (28 Oct): Patchy AM Fog...Mainly South. Sunny and Near Record Warmth. 43/71 Wed (29 Oct): Mostly Sunny. Increasing Clouds Late. 42/65 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Oct 23 08:04:05 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 23 Oct 2008 10:04:05 -0500 Subject: [willamette-fcst] Forecast - Thursday, October 23rd, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, October 23rd, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Stack burning is not allowed. Weather Discussion: A building ridge of high pressure brought sunny skies and offshore flow to western Oregon Wednesday. That sent temperatures over the 70-degree mark in many locations, especially along the coast. Tillamook and Newport both hit 73 degrees, and Astoria was 71. It took the Willamette Valey longer to heat up, due to steep morning temperature inversions and areas of fog. Hillsboro still managed 70 degrees. Aurora, McMinnville, and Salem all hit 69. Fog took the longest to leave Eugene, so the high was just 64. Satellite imagery and the ODA surface analysis showed a very weak cold front stretching from northeastern Washington to the northwest corner of Oregon at mid-morning. It dropped close to a tenth of an inch of rain in northwest Washington but only .01 inches as far south as Astoria, Oregon. Skies were mostly cloudy across Washington with a little rain still falling in the Seattle area. Mostly cloudy skies extended south across the northern half of Oregon, but Doppler radar was not showing any rainfall south of the Washington/Oregon border. Temperatures were able to cool close to the freezing mark, across sections of the Willamette Valley, before clouds increased this morning. McMinnville, Corvallis, and Eugene dipped to 32 degrees and Hillsboro hit 33. The weak frontal system helped prevent fog formation this morning with only the Eugene area reporting some light fog. The cold front is forecast to continue to weaken and push east of the Cascades this afternoon, with skies slowly clearing across western Oregon. The Salem sounding this morning showed several degrees of cooling aloft, so high temperatures will be 5-10 degrees cooler today across the Willamette Valley and 10-15 degrees cooler along the coast. Mixing heights will be a little higher today but still peak at only about 2500 feet this afternoon. Forecast northerly transport winds this afternoon are not conducive to good ventilation for stack burning. Clearing skies overnight should allow valley temperatures to drop into the low to mid 30s again with temperature inversions and areas of fog forming. Surface Winds: N 2-6 this morning, N 5-10 this afternoon. Transport Winds: N 6 this morning, N 8 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2500 feet. Ventilation index 20. High Temperature: Salem\'s high temperature today will be near 64. Humidities: Relative humidity drops to 50% by 2pm. Minimum relative humidity will be near 43%. Sunrise/Sunset: Salem sunset tonight: 6:13pm; sunrise tomorrow: 7:40am. Extended Outlook: Another cold front is forecast slide north of the regin Friday, maintaining some clouds with onshore flow and seasonal temperatures. Rainfall should stay north or Oregon, except for some drizzle or sprinkles along the north coast and western slopes of the north coast range. A strong ridge of high pressure is still forecast to build over the region this weekend and last through the first half of next week. Offshore flow will increase, beginning Saturday, which will send temperatures well above normal, again, with sunny skies statewide. It is possible that western Oregon highs could locally climb into the low 70s, again, Sunday and Monday, which would be near-record warmth for late October. The protective ridge of high pressure is forecast to begin shifting east by Tuesday afternoon with southwesterly flow aloft developing and the surface flow turning onshore. That should cool high temperatures back into the mid 60s. A weak frontal system will likely make it through the ridge late Wednesday and/or Thursday for further cooling. This system does not appear very strong, with just a chance of some light rain, but it should return us to a more seasonal weather pattern. Tomorrow (24 Oct): Partly Sunny. 37/64 Sat (25 Oct): Mostly Cloudy AM. Afternoon Clearing. 39/65 Sun (26 Oct): Patchy AM Fog...Mainly South. Sunny and Very Mild. 35/70 Mon (27 Oct): Patchy AM Fog...Mainly South. Sunny and Very Mild. 36/70 Tue (28 Oct): Patchy AM Fog...Mainly South. Mostly Sunny but a Little Cooler. 38/64 Wed (29 Oct): Increasing Clouds. Chance of Light Rain Late. 42/61 Thu (30 Oct): Mostly Cloudy. Chance of Light Rain. 42/58 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Wed Oct 29 08:04:07 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Wed, 29 Oct 2008 10:04:07 -0500 Subject: [willamette-fcst] Forecast - Wednesday, October 29th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Wednesday, October 29th, 2008 at 9:00am. Burn Advisory: Agricultural burning is not recommended. Stack burning is not allowed. Weather Discussion: The large upper-level ridge of high pressure that has been bringing dry and unseasonably warm weather to the region is moving east and was centered over the Rockies this morning. Increasing southwesterly flow aloft has spread middle and high clouds across northwestern and northcentral Oregon and the western half of Washington. Marine low clouds had also penetrated inland, across the Willamette Valley, this morning with areas of fog. The Salem sounding this morning continued to show very warm air aloft with a strong temperature inversion from about 2500-4500 feet. Mixing heights will not climb above the base of that inversion this afternoon. Very light southwesterly transport winds will make for poor ventilation conditions today. The ODA surface analysis showed high pressure centers over southeastern Oregon and over the southern Oregon coast with very weak pressure-gradients over the Willamette Valley. Valley winds were light and variable. Temperatures dropped into the upper 30s across sections of the valley early this morning and ranged from the upper 30s to the upper 40s at mid-morning. Satellite imagery showed a nearly stationary frontal boundary extending from Vancouver Island, British Columbia southeastward to about 300 miles off the Oregon Coast. It should stay offshore today, allowing for some filtered afternoon sunshine to warm valley temperatures into the upper 50s and low 60s, much like on Tuesday. Winds will stay light and variable. Surface Winds: Var 0-4 this morning, Var 2-4 this afternoon. Transport Winds: SW 4 this morning, SW 4 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 2500 feet. Ventilation index 10. High Temperature: Salem\'s high temperature today will be near 62. Humidities: Minimum relative humidity will be near 57%. Sunrise/Sunset: Salem sunset tonight: 6:04pm; sunrise tomorrow: 7:49am. Extended Outlook: The offshore frontal boundary will slowly move closer to the coastline Thursday with increasing southerly flow aloft. That will further warm the air aloft and suppress mixing heights. Transport winds will increase and become south-southeasterly. Clouds will also increase, but the rain should stay offshore for one more day, before moving inland Thursday night. The first in a series of weather systems will move across Oregon Friday with some light rain likely in the Willamette Valley. This system should lose a lot of strength, as it pushes into the strong ridge of high pressure, but it will open the door for subsequent systems to bring more substantial precipitation to the region. A stronger weather system is slated to come onshore late Saturday, with the main jeet stream energy aimed at northern California. It should still bring increasing rain to the Willamette Valley Saturday night with showers and somewhat blustery conditions Sunday. Another system is forecast to move onshore Monday. High pressure may build into the west coast by late in the week, with the flow aloft drying out and turning northwesterly. Tomorrow (30 Oct): Mostly Cloudy and Very Mild. 44/66 Fri (31 Oct): Light Rain Likely With More Seasonal Temperatures. 48/59 Sat (01 Nov): Rain Likely by Evening. 46/56 Sun (02 Nov): Rain Turning to Showers. 45/54 Mon (03 Nov): Rain Likely. 42/53 Tue (04 Nov): Decreasing Showers. 42/53 Wed (05 Nov): Partly Sunny. 35/56 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Thu Oct 30 08:06:17 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Thu, 30 Oct 2008 10:06:17 -0500 Subject: [willamette-fcst] Forecast - Thursday, October 30th, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Thursday, October 30th, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 12:00pm until 4:00pm. Stack burning is not allowed. Weather Discussion: The protective upper-level ridge of high pressure that brought an extended period of dry and mild weather to the region is continuing to shift eastward with increasing southwesterly flow aloft over Oregon. The Salem sounding this morning showed further warming aloft, compared with Wednesday morning, and a strong low-level temperature inversion from about 1000 to 1800 feet. Transport winds were southerly at about 8 mph. Increasing southwesterly winds aloft were blowing at over 50 mph above 8000 feet...an indication of major changes on the horizon. Satellite imagery showed cloudy skies covering virtually all of Washington and Oregon this morning, due to the moist southwesterly flow aloft. However, Doppler radar was not showing more than perhaps a few sprinkles from those clouds, with the mid-levels of the air mass still quite dry. The ODA surface analysis showed offshore gradients increasing across western Oregon, in response to the approaching cold front. Increasing southeasterly winds will help mix warmer air aloft down to the surface, which should raise valley temperatures into the low 60s this afternoon (Salem only reached 54 degrees Wedneday, due to light winds and a low-level temperature inversion). The offshore frontal boundary will slowly move closer to the coastline today with the flow aloft turning southerly and continuing to increase. That will keep the air mass aloft warm and mixing heights quite low again today. Skies will remain cloudy with a few sprinkles possible...mainly along the coast. Rain will spread inland by Friday morning with between one-tenth and one-quarter of an inch of rain likely during the day Friday. There may be a break in the rain Halloween night. Surface Winds: SE 4-8 this morning, SE 5-10 this afternoon. Transport Winds: S 8 this morning, S 10 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 1800 feet. Ventilation index 18. High Temperature: Salem\'s high temperature today will be near 61. Humidities: Minimum relative humidity will be near 58%. Sunrise/Sunset: Salem sunset tonight: 6:02pm; sunrise tomorrow: 7:50am. Extended Outlook: A few showers should also make it east of the Cascades Friday, but this cold front will weaken considerably, as it attempts to push into the ridge of high pressure over the western half of the country. Another weather system is slated to come onshore late Saturday, but the main jet stream energy is aimed at Northern California, which will help to split and weaken this system. Showers will give way to a more steady rain Sunday, as a stronger system moves onshore. Colder air aloft will drop the snow level to about 5000 feet in the Cascades. A strong westerly flow aloft will keep some rain in the forecast on Monday with the snow level dropping to near 4000 feet late. Another system is forcast to come onshore Tuesday with showers lingering into Wednesday. A warm front will increase clouds on Thursday, but the bulk of the rain appears as if it will stay north over Oregon. A transitory ridge of high pressure may bring brief late Thursday into Friday, but the overall weather pattern will likely remain damp. Tomorrow (31 Oct): Light Rain Likely...Decreasing by Halloween night. 48/61 Sat (01 Nov): Increasing Rain in the Afternoon. 46/59 Sun (02 Nov): Showers Early...Increasing Rain Late. Snow Level Dropping to 5000 Feet. 45/54 Mon (03 Nov): Rain Turning to Showers. Snow Level Near 4000 Feet. 42/53 Tue (04 Nov): Increasing Rain. Snow Level Rising to Above 5000 Feet. 42/53 Wed (05 Nov): Decreasing Showers. 38/56 Thu (06 Nov): Mostly Cloudy. Chance of Light Rain...Mainly North. 41/54 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Oct 31 08:04:25 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 31 Oct 2008 10:04:25 -0500 Subject: [willamette-fcst] Forecast - Friday, October 31st, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. Issued: Friday, October 31st, 2008 at 9:00am. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from 8:00am until 4:00pm. Stack burning is not allowed. Weather Discussion: Increasing southerly flow aloft brought cloudy skies to western Oregon Thursday and strengthened the low-level temperature inversions over the Willamette Valley. The Salem sounding from late Thursday afternoon showed temperaturs at 2000 feet in the upper 60s, while surface temperatures were only in the mid 50s. That made for poor ventilation conditions Thursday, with light transport winds and mixing heights generally below 1000 feet. The first in a series of weather systems ended the extended dry spell and brought rain onshore Thursday night. Light rain continued to fall across most of western Oregon this morning with amounts in the Willamette Valley generally ranging from one-tenth to one-quarter of an inch. Doppler radar showed the main area of rain moving north across the Willamette Valley at mid-morning with the back edge of the steady precipitation near Eugene. The rain should taper off this afternoon, from south-to-north, across the Willamette Valley. Skies will likely stay mostly cloudy through tonight, with satellite imagery not showing many cloud-breaks in wake of the steady rain. At least it look mostly dry for the trick-or-treaters tonight, witch is good. The Salem sounding this morning showed considerable cooling aloft, since Thursday afternoon, with temperatures at 2000 feet dropping from the upper 60s to the low 50s (about the same as currect surface temperatures). Normally, that would promote better mixing of the air mass. However, a developing storm system, about 600 miles off the northern California coastline, will maintain southerly flow aloft and offshore surface winds this afternoon. That will likely keep surface temperatures at or below 60 degrees and reform the low-level temperture inversion over the valley. The combination of low mixing heights and south-southeasterly low-level winds makes conditions unfavorable for stack burning today. Surface Winds: SE 4-8 this morning, SE 5-10 this afternoon. Transport Winds: SE 4 this morning, S 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 1800 feet. Ventilation index 22. High Temperature: Salem\'s high temperature today will be near 60. Humidities: Minimum relative humidity will be near 69%. Sunrise/Sunset: Salem sunset tonight: 6:01pm; sunrise tomorrow: 7:51am. Extended Outlook: The next weather system will spilt as it move onshore late Saturday, with the main jet stream energy aimed at northern California. It will still bring increasing rain to western Oregon, with total rainfall amounts around one-quarter of an inch (similar to today). Offshore surface winds will likely keep high temperatures in the upper 50s Saturday afternoon. An upper-level trough will bring cooling aloft Sunday and Monday with the flow aloft, and at the surface, turning onshore. That should promote better mixing of the air mass and improve ventilation conditions. It will also maintain shower activity with enhanced precipitation over the mountains. More rain will also make it east of the Cascades. Colder air aloft will drop the snow level to about 5000 feet, in the Cascades, by late Sunday and to 4000 feet by late Monday. The upper-level trough is forecast to push east of the region Tuesday afternoon with the flow aloft turning northwesterly and beginning to dry out. A warm front will likely be strong enough to bring light rain to western Oregon Wednesday, as it pushes the snow level back above the Cascade passes. The long-range computer model forecasts diverge late next week, with some calling for ridging and dry conditions and others maintaining a more damp westerly flow aloft. The ODA Seasonal Climate Outlook favors drier conditions returning, so I have leaned the forecast in that direction for next Thursday and Friday. Tomorrow (01 Nov): Increasing Light Rain in the Afternoon. 50/59 Sun (02 Nov): Showers Early...Increasing Rain Late. Snow Level Dropping to 5000 Feet. 48/57 Mon (03 Nov): Rain Likely with Snow in the Mountains. Snow Level Near 4000 Feet. 43/54 Tue (04 Nov): Showers. Snow Level 3500 feet. 42/52 Wed (05 Nov): Light ain Likely...Mainly North. Snow Level Rising to 5500 Feet Late. 38/52 Thu (06 Nov): Mostly Cloudy. Areas of Fog. Chance of Light Rain...Mainly North. 40/55 Fri (07 Nov): Mostly Cloudy. Areas of Fog. Chance of Light Rain...Mainly North. 40/55 ODA Meteorologist weather at oda.state.or.us From willamette-fcst at listsmart.osl.state.or.us Fri Oct 31 11:13:01 2008 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Ag/Burning Forecast) Date: Fri, 31 Oct 2008 13:13:01 -0500 Subject: [willamette-fcst] Forecast - Friday, October 31st, 2008 Message-ID: Daily Smoke Management Forecast Oregon Department of Agriculture Smoke Management Program Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts. ...Next Update Tuesday, November 4th, at 9 a.m. NOON UPDATE Issued: Friday, October 31st, 2008 at 12:00pm. Burn Advisory: Agricultural burning is allowed. Suggested burn times are from now until 4:00pm. Stack burning is not allowed. Weather Discussion: The first in a series of weather systems ended the extended dry spell with rain coming onshore Thursday night. Rain continued to fall across the Willamette Valley through most of the morning but was tapering off to lighter showers at midday. Rainfall totals generally ranging from one-quarter to one-third of an inch. Doppler radar showed the main area of rain had moved north into Washington with a trailing band of showers stretching from the north coast to the northern Willamette Valley. The rain had come to a halt south of about Salem. However, valley temperatures had only warmed into the mid 50s with continued light southeasterly winds. A developing storm system, about 600 miles off the northern California coastline, will maintain southerly flow aloft and offshore surface winds this afternoon. That will maintain low mixing heights with south-southeasterly low-level winds. Satellite imagery was showing a few breaks in the clouds over the south valley that will likely move north this afternoon. A touch of sunshine would help lift valley temperatures to near 60 degrees. There is still a chance of a light shower this afternoon, but things are drying out. Skies will likely stay mostly cloudy this evening, but there is a ghoul chance of dry conditions for the trick-or-treaters. It will also be a relatively mild evening, with temperatures staying in the mid 50s, witch is good. Surface Winds: SE 5-10 this afternoon. Transport Winds: S 12 this afternoon. Atmospheric Ventilation Conditions: Maximum mixing height today will be near 1800 feet. Ventilation index 22. High Temperature: Salem\'s high temperature today will be near 60. Humidities: Minimum relative humidity will be near 69%. Sunrise/Sunset: Salem sunset tonight: 6:01pm; sunrise tomorrow: 7:51am. Extended Outlook: The next weather system will split as it moves onshore late Saturday, with the jet stream aimed at central California. It will still bring increasing rain to western Oregon, with total rainfall amounts around one-quarter of an inch (similar to today). Offshore surface winds will likely keep high temperatures in the upper 50s Saturday afternoon. An upper-level trough will bring cooling aloft Sunday and Monday with the flow aloft, and at the surface, turning onshore. That should promote better mixing of the air mass and improve ventilation conditions. The jet stream will still take the bulk of the rain into California, with lighter rain at times across Western Oregon. Rain and snow will be enhanced over the mountains, due to upslope flow. Some rain will also make it east of the Cascades. Colder air aloft will drop the snow level to about 5000 feet, in the Cascades, by late Sunday and to between 3500 and 4000 feet Monday. The upper-level trough is forecast to push east of the region Tuesday afternoon with the flow aloft turning northwesterly and beginning to dry out. A warm front will likely bring steady rain to western Oregon Wednesday, as it pushes the snow level back above the Cascade passes. The long-range computer model forecasts diverge late next week, with some calling for dry conditions and others maintaining a damp westerly flow aloft. The ODA Seasonal Climate Outlook favors drier conditions returning, so I have leaned the forecast in that direction for next Thursday and Friday. Tomorrow (01 Nov): Increasing Light Rain in the Afternoon. 50/59 Sun (02 Nov): Showers Early...Increasing Rain Late. Snow Level Dropping to 5000 Feet. 48/57 Mon (03 Nov): Rain Likely...Mainly South. Snow Level 3500-4000 Feet. 43/54 Tue (04 Nov): Decreasing Showers. Snow Level 3500-4000 feet. 42/52 Wed (05 Nov): Rain Likely. Snow Level Rising to 6000 Feet Late. 38/52 Thu (06 Nov): Mostly Cloudy. Areas of Fog. Slight Chance of Light Rain. 40/55 Fri (07 Nov): Mostly Cloudy. Areas of Fog. Chance of Light Rain...Mainly North. 40/55 ODA Meteorologist weather at oda.state.or.us