From willamette-fcst at listsmart.osl.state.or.us Fri Aug 1 08:54:56 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 1 Aug 2014 08:54:56 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT FRI AUG 1, 2014 BURN ADVISORY: State Fire Marshal Burn-Ban Conditions may be reached this afternoon. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: There have been subtle changes to the overall weather pattern in the past 24 hours. A warm southwesterly flow aloft is continuing to periodically send upper-air disturbances across the state...triggering clusters of thunderstorms. The daily focus of these storms has been along a nearly stationary thermal trough axis, extending from SW Oregon to north-central Oregon. However, that focus has shifted westward, with one such system moving northward across the Willamette Valley overnight, producing significant lightning and gusty winds from Eugene to Portland. Dry air in the lower levels of the atmosphere lead to the gusty winds and also held rainfall totals to generally around one-tenth of an inch or less. Radar and lightning detection were both indicating active thundershowers continuing over the Cascade foothills, from east of Salem northward to east of Portland, at mid-morning. These storms should slowly weaken as they migrate northward. The upper-air sounding over Salem this morning looked very similar to Thursday's sounding, except for being slightly more unstable in the mid-levels of the atmosphere. The surface thermal trough, which has been over central Oregon, has shifted westward to over the western Cascade foothills. That has turned pressure gradients offshore from Redmond to Salem, with onshore gradients from Newport to Salem. As skies clear later this morning, temperatures should rapidly warm, with afternoon highs once again in the low to mid 90s. Transport winds should be northerly this afternoon, and State Fire Marshal Burn-Ban Conditions may be reached. Daytime heating will, once again, destabilize the lower levels of the air mass, leading to additional thundershower development. The focus of the storms will be mainly over the Cascades, but it is possible that storms could move over the Willamette Valley again later today through tonight. TODAY'S FORECAST: Lingering thunderstorms this morning... Partly cloudy and hot again this afternoon with a chance of thunderstorms returning late. Salem's high temperature today will be near 94?F (average is 84?F). Relative humidity: Dropping to near 50% by 11 a.m. and below 30% by 5 p.m. Surface winds: N 5-10 mph this morning; N 8-15 mph this afternoon. Transport winds: NNE 10 mph this morning; N 15 mph this afternoon. Mixing height: Rising to near 4000 feet by 5 p.m. Salem's sunset tonight: 8:38 p.m. (Salem Airport data for Thursday, July 31st: High 94?F; Rainfall: Trace) (Salem Airport rainfall so far today: .15") (Maximum Ventilation Index expected today: 60) EXTENDED DISCUSSION: A strong upper-level ridge of high pressure will remain anchored just east of the state through early next week. That will maintain a warm south to SW flow aloft over Oregon, with continued above normal temperatures and clusters of mainly afternoon and evening thunderstorms. There will continue to be an elevated chance of thunderstorms over the Willamette Valley through Saturday, with the storm focus shifting to mainly from the Cascades eastward by Sunday. The upper-level ridge is forecast to weaken slightly by Tuesday. Increasing onshore flow will likely shift the thundershower threat well east of the region and cool temperatures back into the upper 80s. Transport winds may turn enough onshore to allow for some burning. Additional weakening of the ridge may further increase the onshore flow by Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 35840 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Aug 1 11:47:58 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 1 Aug 2014 11:47:58 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT FRI AUG 1, 2014 BURN ADVISORY: State Fire Marshal Burn-Ban Conditions may be reached this afternoon. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: The flow aloft backed from southwesterly to south-southeasterly overnight, sending an upper-level disturbance northward across western Oregon. Widespread thundershowers, from the coast range to the Cascades, produced gusty winds and locally around one-tenth of an inch of rain up the length of the Willamette Valley. That weather system has moved into Washington, with clearing skies at midday across NW Oregon. The flow aloft has reverted back to southwesterly, temporarily stabilizing the air mass over NW Oregon. However, the surface thermal trough, which has been over central Oregon, also migrated westward and remains over the western Cascade foothills. As daytime heating destabilizes the lower levels of the air mass, new thundershowers are most likely to develop along that trough axis this afternoon and overnight, posing a threat to the Willamette Valley. In the meantime, valley temperatures are already near 80? F and should climb into the low to mid 90s again this afternoon. With humidity levels likely dropping below 30% today, increasing surface winds and temperatures threaten to put the valley into State Fire Marshal Burn-Ban Conditions again this afternoon. With the thermal trough positioned west of the Cascade crest, pressure gradients remain offshore from Redmond to Salem, which is also unfavorable for burning. Transport winds should remain NE to N today and will be confirmed via a 2 p.m. PIBAL. TODAY'S FORECAST: Partly cloudy and hot with a chance of thunderstorms returning late. Salem's high temperature today will be near 94?F (average is 84?F). Relative humidity: Dropping below 30% by 5 p.m. Surface winds: N 8-15 mph. Transport winds: N 15 mph. Mixing height: Rising to near 4000 feet by 5 p.m. Salem's sunset tonight: 8:38 p.m. (Salem Airport rainfall so far today: .15") (Maximum Ventilation Index expected today: 60) EXTENDED DISCUSSION: A strong upper-level ridge of high pressure will remain anchored just east of the state through early next week. That will maintain a warm south to SW flow aloft over Oregon, with continued above normal temperatures and clusters of mainly afternoon and evening thunderstorms. There will continue to be an elevated chance of thunderstorms over the Willamette Valley on Saturday, with the storm focus shifting to mainly from the Cascades eastward on Sunday. The upper-level ridge is forecast to weaken slightly by Tuesday. Increasing onshore flow will likely shift the thundershower threat well east of the region and cool temperatures back into the upper 80s. Transport winds may turn enough onshore to allow for some burning. Additional weakening of the ridge may further increase the onshore flow by Friday, creating another potential burning opportunity. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34816 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Aug 4 08:41:50 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 4 Aug 2014 08:41:50 -0700 Subject: [willamette-fcst] Willamette Valley Open Burning Forecast Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT MON AUG 4, 2014 BURN ADVISORY: State Fire Marshal Burn-ban conditions may be reached this afternoon. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level ridge extends over the state with the axis over the intermountain states and Rockies. Weak marine layer is along the coast with just minor inland penetration. Otherwise skies are clear with smoke from wildfires in southern Oregon and northern California providing hazy conditions. Current pressure gradients are +3.2 mb from Newport to Salem and +.5 mb from Salem to Redmond. Upper air sounding shows a deep stable layer with generally light northerly winds at 5 - 15 mph to 5000 ft. Little change today with the high pressure ridge remaining anchored in place to the east. With weak southerly flow aloft, some thunderstorms will likely develop along the Cascade crest and prevent much gradient stacking from Salem to Redmond during the afternoon hours. In general, expect mostly northerly low-level flow through the day with minor marine onshore flow late this afternoon and evening. Skies will remain clear but hazy and temperatures fairly hot, getting into the low 90s. TODAY'S FORECAST: Clear and very warm. Salem's high temperature today will be near 93 degrees (average is 84). Relative humidity: Dropping to 60 percent by 10 a.m. and dropping to 28 - 30 percent around 4 p.m. Surface winds: Light and variable, increasing to northerly at 6 - 12 mph by late morning into the mid-afternoon, NW to NNW late this afternoon and evening. Transport winds: Northerly at 5 - 8 mph during the morning becoming mostly northerly at 8 - 15 mph this afternoon, and NW to N late afternoon and evening at 8 - 15 mph. Mixing height: Morning below 2500 ft, rising to near 3000 ft by 1 p.m. and to 4500 ft by 5 p.m. Salem's sunset tonight: 8:34 p.m. (Salem Airport data for Sunday, Aug 3rd: High 94?F; Rainfall: .00") (Maximum Ventilation Index expected today: 54) EXTENDED DISCUSSION: Upper level ridge gradually flattens over the next few days opening the door to a little earlier and stronger onshore flow during the afternoon and evening. Expect slightly cooler temperatures. In addition, thunderstorms on the east side of the Cascades will be less prevalent. However, still expect mostly northerly to northwesterly flow. Marginal burning conditions will still be about the best that can be mustered. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Nick.doc Type: application/msword Size: 35328 bytes Desc: Silverton Hills AM Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Aug 4 11:50:37 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 4 Aug 2014 11:50:37 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast - Noon Update Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT MON AUG 4, 2014 BURN ADVISORY: State Fire Marshal Burn-ban conditions may be reached this afternoon. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level ridge extends over the state with the axis over the intermountain states and the Rockies. Weak marine layer is along the coast with just minor inland penetration. Otherwise skies are clear with smoke from wildfires in southern Oregon and northern California providing hazy conditions. Current pressure gradients are +3.5 mb from Newport to Salem and +.4 mb from Salem to Redmond. Little change today with the high pressure ridge remaining anchored in place to the east. With weak southerly flow aloft, some thunderstorms will likely develop along the Cascade crest and prevent much gradient stacking from Salem to Redmond during the afternoon hours. In general, expect mostly northerly low-level flow through the day with minor marine onshore flow late this afternoon and evening. Skies will remain clear but hazy and temperatures fairly hot, getting into the low 90s. TODAY'S FORECAST: Clear, hazy and very warm. Salem's high temperature today will be near 93 degrees (average is 84). Relative humidity: Dropping to 28 - 30 percent around 4 p.m. Surface winds: Light and variable, increasing to northerly at 6 - 12 mph by early afternoon. NW to NNW late this afternoon and evening. Transport winds: Northerly at 5 - 8 mph during the morning increasing to northerly at 8 - 15 mph this afternoon, and NW to N late afternoon and evening at 8 - 15 mph. Mixing height: Rising to near 3000 ft by 1 p.m. and to 4500 ft by 5 p.m. Salem's sunset tonight: 8:34 p.m. (Salem Airport data for Sunday, Aug 3rd: High 94?F; Rainfall: .00") (Maximum Ventilation Index expected today: 54) EXTENDED DISCUSSION: Upper level ridge gradually flattens over the next few days opening the door to a little earlier and stronger onshore flow during the afternoon and evening. Expect slightly cooler temperatures. In addition, thunderstorms on the east side of the Cascades will be less prevalent. However, still expect mostly northerly to northwesterly flow so marginal burning conditions will be about the best we get this week. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Nick.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Aug 5 08:41:38 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 5 Aug 2014 08:41:38 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT MON AUG 4, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from noon to 2 p.m. with a 50 acre limit. WEATHER DISCUSSION: Upper level ridge remains over the state and to the east. Morning sounding still shows the marine air that came in last evening with NW winds up to 2000 ft. Current pressure gradients are +1.9 mb from Newport to Salem and have increased to +3.6 mb from Salem to Redmond. However, smoky and hazy skies remain from wildfire smoke to our south. Ridge will slowly weaken and move to the east today. This minor shift will aid in dispersing wildfire smoke that has been over the area. With the marine air that came in last evening, expect several degrees of cooling from yesterday. However, wind flow will turn back to NNW to N later this morning and remain no better than NNW until early evening. TODAY'S FORECAST: Hazy with variable clouds. Clearing through the day. Cooler. Salem's high temperature today will be near 87 degrees (average is 84). Relative humidity: Dropping to 60 percent by 10 a.m. and dropping to near 35 percent around 4 p.m. Surface winds: Light and variable favoring NW to N this morning. Increasing to NNW to N at 6 - 12 mph by early afternoon and turning to NW during the early evening. Transport winds: NW to N at 5 - 10 mph during the morning becoming NNW to N at 6 - 12 mph this afternoon, and NW'erly at 8 - 15 mph this evening. Mixing height: Rising to near 3000 ft by noon and to 4500 - 5000 ft by 5 p.m. Salem's sunset tonight: 8:33 p.m. (Salem Airport data for Monday, Aug 4th: High 94?F; Rainfall: .00") (Maximum Ventilation Index expected today: 54) EXTENDED DISCUSSION: Upper level ridge gradually flattens over the next few days bringing high temperatures down to near average. However, models show wind flow remaining quite northerly with just minor onshore NNW to NW flow during the later afternoon to evening hours. Mixing levels should be fair to good during the day but with winds showing considerable northerly flow, burning opportunities will be limited. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Nick.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Aug 5 11:50:45 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 5 Aug 2014 11:50:45 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast - Noon Update Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT TUES AUG 5, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from noon to 2 p.m. with a 50 acre limit. WEATHER DISCUSSION: Upper level ridge remains over the state and to the east. With little upper level air movement, smoky and hazy skies from wildfire smoke remains. Current pressure gradients are +1.7 mb from Newport to Salem and +4.0 mb from Salem to Redmond. Ridge will slowly weaken and move to the east today. This minor shift will eventually aid in the dispersing wildfire smoke. With the marine air that came in last evening, expect several degrees of cooling from yesterday. However, wind flow is turning back to NNW to N and will remain no better than NNW until early evening. TODAY'S FORECAST: Mostly hazy. Some clearing through the day. Cooler. Salem's high temperature today will be near 86 degrees (average is 84). Relative humidity: Dropping to near 35 percent around 4 p.m. Surface winds: NNW to N at 6 - 12 mph by early afternoon, turning to NW during the early evening. Transport winds: NNW to N at 6 - 12 mph this afternoon, turning NW'erly at 8 - 15 mph this evening. Mixing height: Rising to 4500 - 5000 ft by 5 p.m. Salem's sunset tonight: 8:33 p.m. (Salem Airport data for Monday, Aug 4th: High 94?F; Rainfall: .00") (Maximum Ventilation Index expected today: 54) EXTENDED DISCUSSION: Upper level ridge gradually flattens over the next few days bringing high temperatures down to near average. However, models show wind flow remaining quite northerly with just minor onshore NNW to NW flow during the later afternoon to evening hours. Mixing levels should be fair to good during the day but with winds showing considerable northerly flow, burning opportunities will be limited. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Nick.doc Type: application/msword Size: 33792 bytes Desc: Silverton Hills Midday Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Aug 6 08:57:13 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 6 Aug 2014 08:57:13 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT WED AUG 6, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from 11 a.m. until 1 p.m. with a 50 acre limit. WEATHER DISCUSSION: An upper-level trough, extending from Idaho to California, is finally shifting eastward in response to an increasing westerly flow aloft pushing over western Oregon. Increasing onshore flow has cleared wildfire smoke from the skies over the Willamette Valley this morning. It has also pushed marine clouds inland up the Columbia River into the Portland area and through the central coast range gaps into Eugene. Some low clouds may penetrate into Marion and Linn Counties later this morning. The limiting factors for burning today will be wind direction and pressure gradient-stacking. Cooling aloft and surface warming should help mixing heights climb to near 5000 feet by late this afternoon. The latest computer guidance is predicting northwesterly winds this afternoon, which would be favorable for burning. If the central Willamette Valley can avoid the marine clouds this morning, that will increase the chances for burning opportunities today. Daytime heating will be needed to reverse the "stacking" of the onshore pressure gradients. Clear skies will speed up that process. TODAY'S FORECAST: Areas of morning clouds possible. Sunny and a little cooler. Salem's high temperature today will be near 83?F (average is 84?F). Relative humidity: Dropping to near 60% by 11 a.m. and to near 40% by 5 p.m. Surface winds: N 5 mph this morning; NNW 5-10 mph this afternoon. Transport winds: NNW 5-10 mph this morning; NW 10-15 mph this afternoon. Mixing height: Rising to 3000 feet around 11 a.m. and to 5000 feet by 5 p.m. Salem's sunset tonight: 8:31 p.m. (Salem Airport data for Tuesday, August 5th: High 86?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: A cooler and stable westerly flow aloft on Thursday is predicted to become more southwesterly on Friday, with continued onshore flow. Expect some morning marine clouds each day with sunny afternoons. Transport winds should be mostly northerly but may turn enough northwesterly to allow for limited burning, if pressure gradient-stacking can be balanced by daytime heating. A weak upper-level trough may trigger some thundershowers over the Cascades this weekend. It is possible that the flow aloft could turn enough southerly to send thunderstorms over the Willamette Valley Sunday night into Monday morning. Otherwise, expect a continuation of mild and dry conditions with onshore flow. A little stronger trough is forecast to increase the onshore flow on Tuesday with temperatures cooling to below average. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Aug 6 11:49:27 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 6 Aug 2014 11:49:27 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT WED AUG 6, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from now until 1 p.m. with a 50 acre limit. WEATHER DISCUSSION: Increasing westerly flow aloft has cleared wildfire smoke from the skies over NW Oregon, with onshore flow cooling temperatures back to near average. Marine low clouds were able to penetrate into the extreme northern and southern ends of the Willamette Valley this morning, but skies stayed clear over the mid-valley region. Mixing heights should rise to near 5000 feet later this afternoon, and ample sunshine has already balanced the onshore flow from Newport to Redmond. However, an 11 a.m. PIBAL showed north to NE winds in the transport layer, which are not favorable for burning. Winds are predicted to back to northerly, and perhaps northwesterly, this afternoon and will be monitored closely. The next PIBAL is scheduled for 1 p.m. TODAY'S FORECAST: Sunny and seasonably warm. Salem's high temperature today will be near 84?F (average is 84?F). Relative humidity: Dropping to near 40% by 5 p.m. Surface winds: NNE to NNW 5-10 mph. Transport winds: N-NE 10-15 mph; becoming NW-N 10-15 mph this afternoon. Mixing height: Rising to 5000 feet by 5 p.m. Salem's sunset tonight: 8:31 p.m. (Salem Airport data for Tuesday, August 5th: High 86?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: The flow aloft is predicted to become more southwesterly by Friday, with continued onshore flow. Expect some morning marine clouds both Thursday and Friday with sunny afternoons. Transport winds should be mostly northerly but may turn northwesterly in the afternoons. Daytime mixing should continue to be good, but gradient-stacking may be an issue. Very little change is forecast through Monday. A weak upper-level trough may trigger a few thundershowers over the Cascades this weekend, but it is looking less likely that any precipitation will make its way to the Willamette Valley. A little stronger trough may increase the onshore flow enough to create a burning opportunity next Tuesday, with an upper-level ridge predicted to rebuild over Oregon during the second half of next week. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 33792 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Aug 7 08:53:20 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 7 Aug 2014 08:53:20 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT THU AUG 7, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from noon until 2 p.m. with a 50 acre limit. WEATHER DISCUSSION: Only subtle changes to the weather pattern have occurred since yesterday. The flow aloft has backed from westerly to southwesterly. Otherwise, the morning sounding over Salem looked almost identical to 24 hours ago. Weak onshore flow continues to keep wildfire smoke out of the region but is not strong enough to bring marine low clouds into the central Willamette Valley...leaving skies clear with excellent air quality. The air aloft is cool, so daytime heating should yield high afternoon mixing heights. Onshore pressure gradients should also be favorable to keep smoke elevated. The limiting factor for burning, once again, today will be wind direction. Low-level winds are northeasterly this morning and should turn northerly by early this afternoon. It is possible that transport winds could turn enough north-northwesterly to allow for limited burning. TODAY'S FORECAST: Sunny and seasonably warm. Salem's high temperature today will be near 84?F (average is 84?F). Relative humidity: Dropping to near 50% by 11 a.m. and to near 30% by 5 p.m. Surface winds: N 5-10 mph this morning; N-NNW 7-12 mph this afternoon. Transport winds: NNE 10 mph this morning; N-NNW 10-15 mph this afternoon. Mixing height: Rising to 3000 feet around noon and to 5000 feet by 5 p.m. Salem's sunset tonight: 8:30 p.m. (Salem Airport data for Wednesday, August 6th: High 85?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: Weak southwesterly flow aloft will continue on Friday. Onshore may strengthen enough to bring some patchy brief morning marine clouds into the central valley. Otherwise, skies should be sunny with seasonal temperatures. Afternoon transport winds are predicted to remain generally northerly, so a burning opportunity is unlikely. A weak upper-level trough is forecast to turn the upper-level winds southeasterly by Sunday, which should trigger thundershower activity over the Cascades...possibly drifting over the Willamette Valley Sunday night into Monday morning. Increasing southwesterly flow aloft should push the thundershower threat east of the region on Tuesday, with developing onshore flow possibly creating a burning opportunity. An upper-level ridge predicted to rebuild over Oregon during the second half of next week with mostly northerly transport winds. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Aug 7 11:53:02 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 7 Aug 2014 11:53:02 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT THU AUG 7, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from noon until 2 p.m. with a 50 acre limit. WEATHER DISCUSSION: With the exception of some residual marine clouds near the Columbia River, weak onshore flow is bringing sunny skies, moderate temperatures, and excellent air quality to NW Oregon at midday. Daytime heating has already nearly balanced the onshore flow between Newport and Redmond and likely lifted mixing heights to near 3000 feet. The limiting factor for burning today will be the wind direction. Low-level winds were northeasterly early this morning and are forecast to slowly turn northerly this afternoon. Transport winds could turn enough north-northwesterly to allow for limited burning and will be monitored with PIBALS this afternoon. TODAY'S FORECAST: Sunny and seasonably warm. Salem's high temperature today will be near 84?F (average is 84?F). Relative humidity: Dropping to near 30% by 5 p.m. Surface winds: N-NNW 7-12 mph. Transport winds: N-NNW 10-15 mph. Mixing height: Rising to near 5000 feet by 5 p.m. Salem's sunset tonight: 8:30 p.m. (Salem Airport data for Wednesday, August 6th: High 85?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: Weak southwesterly flow aloft will continue on Friday. Onshore may strengthen enough to bring some patchy marine clouds into the central valley. Otherwise, skies should be sunny with seasonal temperatures. Predicted northerly transport winds will likely inhibit burning. A weak upper-level trough is forecast to turn the upper-level winds southeasterly by Sunday, which should trigger thundershower activity over the Cascades, and possibly NW Oregon, Sunday night into Monday morning. Southwesterly flow aloft should push the thundershower threat east of the region on Tuesday, with increasing onshore flow possibly creating a burning opportunity. An upper-level ridge is forecast to rebuild over Oregon during the second half of next week with mostly northerly transport winds. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 33792 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Aug 8 08:55:09 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 8 Aug 2014 08:55:09 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT FRI AUG 8, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: A dry upper-level trough spread some middle and high clouds across NW Oregon this morning and will push east of the region this afternoon. Weak onshore flow will keep temperatures near average with mostly sunny skies today. The air aloft is cool, so daytime heating should yield high afternoon mixing heights. Onshore pressure gradients are stronger from Salem to Redmond this morning than they are from Newport to Salem. Daytime heating should be sufficient to balance these gradients this afternoon. The limiting factor for burning, once again, today will be wind direction. Low-level winds are northeasterly this morning and should turn northerly this afternoon. It is possible that transport winds could turn north-northwesterly, but that is not predicted by this morning's computer models. TODAY'S FORECAST: Mostly sunny and seasonably warm. Salem's high temperature today will be near 83?F (average is 83?F). Relative humidity: Dropping below 50% by 11 a.m. and to near 30% by 5 p.m. Surface winds: N 5-10 mph this morning; N 7-13 mph this afternoon. Transport winds: NNE 10-15 mph this morning; N 10-15 mph this afternoon. Mixing height: Rising to 3000 feet by noon and to near 5000 feet by 5 p.m. Salem's sunset tonight: 8:29 p.m. (Salem Airport data for Thursday, August 7th: High 86?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: An upper-level trough is forecast to approach the northern California coast on Saturday, turning the flow aloft southeasterly over Oregon. That will warm temperature back to above average, as onshore flow begins to relax. On Sunday, increasing SE flow aloft will circulate more moisture and unstable air northward over Oregon. Thundershowers are likely across southern Oregon and will migrate northward, possibly to over the Willamette Valley, Sunday night through Monday night. Wetting rains are possible from these storms. An approaching trough, from the Gulf of Alaska, will turn the flow aloft southwesterly on Tuesday and should push the thundershower threat east of the region. Increasing onshore flow will cool temperatures back to near normal and may create a significant burning opportunity, if fields are not too damp. Dry and warmer weather is predicted for the second half of next week, with mostly northerly transport winds. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Aug 8 11:55:14 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 8 Aug 2014 11:55:14 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT FRI AUG 8, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Some marine clouds extended from the north coast into the extreme northern Willamette Valley, at midday, with sunny skies elsewhere across western Oregon. Onshore pressure gradients are still stronger from Salem to Redmond than they are from Newport to Salem, but continued heating should be sufficient to balance the onshore flow this afternoon. Mixing heights will be high again today, so the limiting factor for burning will be wind direction. Low-level winds are currently northeasterly and will not likely take on a westerly component today. A PIBAL is scheduled for 2 p.m. TODAY'S FORECAST: Sunny and seasonably warm. Salem's high temperature today will be near 83?F (average is 83?F). Relative humidity: Dropping to near 30% by 5 p.m. Surface winds: NE 7-12 mph; becoming N 8-14 mph. Transport winds: N-NNE 10-15 mph. Mixing height: Rising to near 5000 feet by 5 p.m. Salem's sunset tonight: 8:29 p.m. (Salem Airport data for Thursday, August 7th: High 86?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: An upper-level trough is forecast to approach the northern California coast on Saturday, turning the flow aloft southeasterly over Oregon. That will slacken the onshore flow and warm temperature back to above average. On Sunday, increasing SE flow aloft will further warm temperatures and circulate moisture and instability northward over the state. Scattered thundershowers will likely development over SW Oregon Sunday afternoon and may advance into NW Oregon by Sunday evening. SE flow aloft will continue on Monday, with more clouds likely preventing further warming. Daytime heating should be sufficient to produce at least scattered thundershowers statewide. These storms will produce locally wetting rains. An approaching trough, from the Gulf of Alaska, will turn the flow aloft southwesterly on Tuesday, pushing the thundershowers east of the region. Increasing onshore flow will cool temperatures back to near normal and could create a significant burning opportunity, if fields are not too wet. Dry and warmer weather is predicted for the second half of next week, with transport winds turning mostly northerly. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Aug 11 08:41:38 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 11 Aug 2014 08:41:38 -0700 Subject: [willamette-fcst] Willamette Valley Open Burning Forecast Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT MON AUG 11, 2014 BURN ADVISORY: State Fire Marshal Burn-ban conditions likely to be reached this afternoon. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level ridge is east of the state with a low off the northern California coast bringing upper level southerly flow over the state. This pattern brought thunderstorms into the southern Willamette Valley last evening and overnight cloud cover that has kept low temperatures warm - in the upper 60s. Morning surface chart shows low pressure in the Willamette Valley with higher pressure to both the east and west. Current pressure gradients are +1.8 mb from Newport to Salem and -4.2 mb from Salem to Redmond. Skies are hazy due to wildfire smoke that has drifted up from the south. The low pattern off the coast and the ridge to the east will remain in place and bring a likely repeat of thunderstorms developing and moving into the Willamette Valley this evening. Expect another hot day with temperatures getting into the upper 90s and reaching Fire Marshal conditions. However, it appears some marine air will move in later today and cool temperatures down much quicker than last evening. TODAY'S FORECAST: Hazy with variable clouds. Hot. Salem's high temperature today will be near 97 degrees (average is 83). Relative humidity: Has dropped below 60 percent and will drop to 20 - 25 percent by 4 p.m. Surface winds: Light and variable this morning and into the early afternoon. Winds increase from the SW to NW later this afternoon and evening to 5 - 15 mph. Transport winds: Light and variable during the morning becoming NW to N at 5 - 10 mph this afternoon, shifting to SW to NW at 7 - 15 mph this evening. Mixing height: Rising to near 3000 ft by 2 p.m and to 4500 - 5000 ft by 5 p.m. Salem's sunset tonight: 8:24 p.m. (Salem Airport data for Monday, Aug 4th: High 97?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: Upper level ridge moves off to the east tomorrow with an upper low off the Pacific coast combining with the low off the northern California coast. This will likely bring in more showers and thundershowers in on Tuesday. In addition, marine air moves in and brings SW to NW flow and cooler temperatures. However, with increased threat of moisture fields may get wet and not allow a burn opportunity. The upper low moves in on Wednesday bringing more rain. The low will finally exit to the east on Thursday with drying conditions Thursday afternoon and Friday. Continued onshore flow into the end of the week may provide a burn opportunity if fields dry out enough. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Nick.doc Type: application/msword Size: 34816 bytes Desc: Silverton Hills AM Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Aug 11 11:51:28 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 11 Aug 2014 11:51:28 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast - Noon Update Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT MON AUG 11, 2014 BURN ADVISORY: State Fire Marshal Burn-ban conditions likely to be reached this afternoon. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level ridge is east of the state with a low off the northern California coast bringing upper level southerly flow over the state. Warm nighttime lows have given the morning a higher start to the temperature trend with the 11 a.m. temperature six degrees higher than yesterday at this time yesterday morning. Surface chart shows thermal trough is in the Willamette Valley with higher pressure to both the east and west. Current pressure gradients are +3.2 mb from Newport to Salem and -4.5 mb from Salem to Redmond. Skies are hazy due to wildfire smoke that has drifted up from the south. The low pattern off the coast and the ridge to the east will remain in place and bring a likely repeat of thunderstorms developing and moving into the Willamette Valley this evening. Expect another hot day with temperatures near 100 degrees and reaching Fire Marshal conditions by midafternoon. However, it appears some marine air will move in later today and cool temperatures down much quicker than last evening. TODAY'S FORECAST: Hazy with variable clouds. Hot. Salem's high temperature today will be near 99 degrees (average is 83). Relative humidity: Has dropped below 40 percent and will drop to 20 - 25 percent by 4 p.m. Surface winds: Light and variable this morning and into the early afternoon. Winds increase from the SW to NW later this afternoon and evening to 5 - 15 mph. Transport winds: Light and variable during the morning becoming NW to N at 5 - 10 mph this afternoon, shifting to SW to NW at 7 - 15 mph this evening. Mixing height: Rising to near 3000 ft by 2 p.m and to 4500 - 5000 ft by 5 p.m. Salem's sunset tonight: 8:24 p.m. (Salem Airport data for Monday, Aug 4th: High 97?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: Upper level ridge moves off to the east tomorrow with an upper low off the Pacific coast combining with the low off the northern California coast. This will likely bring in more showers and thundershowers in on Tuesday. In addition, marine air moves in and brings SW to NW flow and cooler temperatures. However, with increased threat of moisture fields may get wet and not allow a burn opportunity. The upper low moves in on Wednesday bringing more rain. The low will finally exit to the east on Thursday with drying conditions Thursday afternoon and Friday. Continued onshore flow into the end of the week may provide a burn opportunity if fields dry out enough. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Nick.doc Type: application/msword Size: 34816 bytes Desc: Silverton Hills Midday Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Aug 12 08:45:16 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 12 Aug 2014 08:45:16 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT TUES AUG 12, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level low in the eastern Pacific is combining with the low off the northern California coast bringing upper and lower level southerly flow over the state. While no thunderstorms moved through the Willamette Valley last night, the area is under convective cloud cover. Currently, a line of thunderstorms are moving up from the Corvallis area now. Temperatures in the mid-Willamette Valley have only cooled slightly from yesterday morning. Morning surface chart shows low pressure still in the Willamette Valley with higher pressure to both the east and west. Current pressure gradients are +2.9 mb from Newport to Salem and -1.5 mb from Salem to Redmond. The combining upper low pattern off the coast will bring in clouds and the chance of showers and thundershowers over the region today and this evening. With more clouds over the area and some cooling aloft, temperatures will likely only reach to the mid-80s. Clouds will also limit mixing heights to most likely under 3000 ft. Despite more favorable S to SW winds today, the possibility of showers, low mixing heights and questionable gradient stacking, will likely limit burn opportunities. TODAY'S FORECAST: Mostly cloudy with possible showers or thundershowers. Salem's high temperature today will be near 85 degrees (average is 83). Relative humidity: Will drop below 60 percent by 10 a.m. and drop to 35 - 40 percent by 4 p.m. Surface winds: Light and variable favoring S to W flow. Winds SW to NW at 5 - 10 mph later this afternoon and evening. Transport winds: S to SW at 4 - 7 mph this morning becoming SW to NW at 6 - 12 mph this afternoon. Mixing height: Remaining below 2000 ft during the morning rising to near 2800 ft by 5 p.m. Salem's sunset tonight: 8:23 p.m. (Salem Airport data for Monday, Aug 11th: High 98?F; Rainfall: .00") (Maximum Ventilation Index expected today: 28) EXTENDED DISCUSSION: Upper level low will move into the state on Wednesday bringing more showers and a chance of thundershowers over the area tomorrow. The low will exit to the east on Thursday with drying conditions Thursday afternoon and Friday. Northwesterly onshore flow continuing into the end of the week may provide a burn opportunity Thursday and/or Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Nick.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Aug 12 11:48:26 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 12 Aug 2014 11:48:26 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast - Noon Update Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT TUES AUG 12, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level low in the eastern Pacific is combining with the low off the northern California coast bringing upper and lower level southerly flow over the state. Current radar imagery shows a line of thunderstorms moving toward Salem from the SSE. Currently, the event is moving through the Corvallis/Albany area. Temperatures are 13 degrees cooler at 11 a.m. than yesterday morning at this time. In addition, morning surface chart shows low pressure is moving east of the Willamette Valley and into the Cascades. Current pressure gradients are +3.1 mb from Newport to Salem and 0.0 mb from Salem to Redmond. It appears the thunderstorm will move into the Salem/Sublimity area shortly after noon and provide a tenth to three tenths of an inch of rain. Expect continued cloud cover and chance of showers or thundershowers into the evening hours. Temperatures will likely struggle to get into the 80s. TODAY'S FORECAST: Mostly cloudy with increasing showers and/or thundershowers. Salem's high temperature today will be near 80 degrees (average is 83). Relative humidity: Will range from 50 to 80 percent this afternoon. Surface winds: SE to WW at 4 - 8 mph, potentially gusty near the thunderstorm. Winds SW to NW at 5 - 10 mph later this afternoon and evening. Transport winds: S to SW at 5 - 10 mph early this afternoon becoming SW to NW at 6 - 12 mph later this afternoon and evening. Mixing height: Rising to near 2500 ft by 5 p.m. Salem's sunset tonight: 8:23 p.m. (Salem Airport data for Monday, Aug 11th: High 98?F; Rainfall: .00") (Maximum Ventilation Index expected today: 25) EXTENDED DISCUSSION: Upper level low will move into the state on Wednesday bringing more showers and a chance of thundershowers over the area. The low will slowly exit to the east on Thursday but significant drying may not occur until Friday. Northwesterly onshore flow will continue into the end of the week and may provide a burn opportunity Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Nick.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Aug 13 08:53:55 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 13 Aug 2014 08:53:55 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT WED AUG 13, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: An upper-level trough is parked over Oregon with clusters of showers and thunderstorms rotating around it. The two main areas of showers this morning are located over western Washington and SW Oregon, with mostly dry conditions sandwiched between them across NW Oregon. As the parent trough very slowly advances eastward today, the area of showers currently across SW Oregon is forecast to circulate northward. That will increase the threat of showers and thundershowers this afternoon across NW Oregon. The air aloft is cool, so daytime heating should yield high afternoon mixing heights. Onshore pressure gradients will increase, with transport winds turning generally westerly this afternoon. Burning chances will depend upon the initial dampness of fields, additional shower activity, and relative humidity levels. TODAY'S FORECAST: Mostly cloudy. Chance of showers and thundershowers. Salem's high temperature today will be near 78?F (average is 83?F). Relative humidity: Dropping below 60% by 2 p.m. and to near 50% by 5 p.m. Surface winds: SSW 2-6 mph this morning; SW 4-8 mph this afternoon. Transport winds: SSW 5-10 mph this morning; W 10-15 mph this afternoon. Mixing height: Rising to 3000 feet by 2 p.m. and to near 5000 feet by 5 p.m. Salem's sunset tonight: 8:21 p.m. (Salem Airport data for Tuesday, August 12th: High 76?F; Rainfall: .13") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: The upper-level trough is forecast to move over eastern Oregon on Thursday and Washington on Friday. The moist circulation around it should maintain mostly cloudy skies, but the threat of showers will decrease. Onshore flow and good mixing may provide burning opportunities both days, if humidity levels are low enough and fields are not too wet. A drier westerly flow aloft is forecast for Saturday through Monday, with onshore flow at the surface. Increasing amounts of sunshine will help temperatures recover to near or slightly above average. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Aug 13 11:56:19 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 13 Aug 2014 11:56:19 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:55 AM PDT WED AUG 13, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Clusters of showers and thunderstorms are rotating around an upper-level trough that extends from eastern Washington to NW California. One large area of showers currently stretches from western Washington across the NW tip of Oregon, with another area of showers extending from SW to north-central Oregon. The Willamette Valley is in a relatively dry slot between these two shower clusters. However, showers are advancing northward along the Cascades and may move over the valley later this afternoon. The air aloft is cool, so daytime heating will yield high mixing heights. Onshore pressure gradients are currently favorable for burning but will need to be monitored. Transport winds are predicted to be westerly, shower development over the Cascades will tend to decrease the onshore flow from Salem to Redmond, which is needed for smoke evacuation. Burning chances today will also depend upon dryness of fields and relative humidity levels. TODAY'S FORECAST: Mostly cloudy. Chance of showers and thundershowers. Salem's high temperature today will be near 78?F (average is 83?F). Relative humidity: Dropping to near 50% by 5 p.m. Surface winds: SW 4-8 mph. Transport winds: W 10-15 mph this afternoon. Mixing height: Rising to near 5000 feet by 5 p.m. Salem's sunset tonight: 8:21 p.m. (Salem Airport data for Tuesday, August 12th: High 76?F; Rainfall: .13") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: The upper-level trough is forecast to move over eastern Oregon on Thursday and eastern Washington on Friday. The moist circulation around it should maintain mostly cloudy skies, but the threat of showers will decrease. Onshore flow and good mixing may provide burning opportunities both days, if humidity levels are low enough and fields are not too wet. A drier westerly flow aloft is forecast for Saturday through Monday, with onshore flow at the surface. Mostly sunny skies will help temperatures recover to slightly above average. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Aug 14 08:58:37 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 14 Aug 2014 08:58:37 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT THU AUG 14, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: A slow-moving upper-level trough is keeping skies generally cloudy across most of Washington and Oregon this morning. There are some breaks in the clouds near the center of circulation, over NW Oregon, with showers across much of Washington and sections of central and SW Oregon. Daytime heating will enhance the shower activity, especially over the northern Cascades, this afternoon. Conditions may be favorable for burning again today, with cool air aloft maintaining high afternoon mixing heights. However, pressure gradients have weakened since yesterday and will need to turn more strongly onshore to allow for smoke evacuation. Transport winds should turn southwesterly to westerly this afternoon and will also need close monitoring. There is also a threat of showers, which could render fields too wet for burning or cause unwanted down-mixing of smoke. TODAY'S FORECAST: Mostly cloudy. Chance of showers and thundershowers. Salem's high temperature today will be near 80?F (average is 83?F). Relative humidity: Dropping below 60% by noon and to near 50% by 5 p.m. Surface winds: S 2-6 mph this morning; SW 5-10 mph this afternoon. Transport winds: S 4-8 mph this morning; SW 5-10 mph this afternoon. Mixing height: Rising to 3000 feet by noon and to near 6000 feet by 5 p.m. Salem's sunset tonight: 8:20 p.m. (Salem Airport data for Wednesday, August 13th: High 80?F; Rainfall: Tr.) (Maximum Ventilation Index expected today: 60) EXTENDED DISCUSSION: The upper-level trough is forecast to move over eastern Washington on Friday. The moist circulation around it should maintain mostly cloudy skies, but the threat of showers will decrease. Onshore flow and good mixing may provide another burning opportunity. A drier westerly flow aloft is forecast for Saturday through Monday, with onshore flow at the surface. Mostly sunny skies will help temperatures recover to slightly above average. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 33792 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Aug 14 11:55:45 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 14 Aug 2014 11:55:45 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT THU AUG 14, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: A slow-moving upper-level low-pressure system, centered over north-central Oregon at midday, is continuing to spin considerable shower activity across Washington and mainly just a lot of clouds across Oregon. Daytime heating will enhance the shower activity somewhat this afternoon, especially over higher terrain. High mixing heights and a predicted westerly component to the transport winds may allow for burning this afternoon. However, some fields are likely too wet (for burning), and shower development could dampen additional fields and cause smoke down-mixing. Conditions will need to be closely monitored. TODAY'S FORECAST: Mostly cloudy. Chance of showers and thundershowers. Salem's high temperature today will be near 80?F (average is 83?F). Relative humidity: Dropping to near 50% by 5 p.m. Surface winds: S 2-6 mph; becoming W 5-10 mph later this afternoon. Transport winds: SW 4-8 mph; becoming W 5-10 mph later this afternoon. Mixing height: Rising to near 6000 feet by 5 p.m. Salem's sunset tonight: 8:20 p.m. (Salem Airport data for Wednesday, August 13th: High 80?F; Rainfall: Tr.) (Maximum Ventilation Index expected today: 60) EXTENDED DISCUSSION: The upper-level trough is forecast to move over eastern Washington on Friday. The moist circulation around it should maintain mostly cloudy skies early, with afternoon clearing. Increasing onshore flow and continued high afternoon mixing heights should provide some opportunity for burning. A drier westerly flow aloft is forecast for Saturday through Monday. Mostly sunny skies will help temperatures recover to slightly above average. Weak onshore flow may provide burning opportunities early next week. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 32768 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Aug 15 08:54:03 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 15 Aug 2014 08:54:03 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT FRI AUG 15, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: The slow-moving upper-level low-pressure system that has produced mostly cloudy and "relatively" cool weather the past three days is centered over NE Oregon this morning. The moist flow around it is continuing to spread clouds across virtually all of Washington and most of northern Oregon. Radar and surface reports indicate some sprinkles across NW Oregon but no significant rainfall. The low-pressure system will continue to migrate to the north and east today, with the air mass slowly warming and drying. However, cool air aloft will yield high mixing heights again this afternoon. Light southwesterly transport winds will slowly veer to westerly, and eventually northwesterly, over the course of the day, as onshore pressure gradients slowly increase. That should make for favorable burning conditions. TODAY'S FORECAST: Cloudy early with possible sprinkles. Partial afternoon clearing. Salem's high temperature today will be near 83?F (average is 83?F). Relative humidity: Dropping to 60% by noon and to near 40% by 5 p.m. Surface winds: S 2-6 mph this morning; becoming WNW 2-6 mph this afternoon. Transport winds: SW 5 mph this morning; becoming WNW 5-10 mph this afternoon. Mixing height: Rising to 3000 feet by noon and above 5000 feet by 5 p.m. Salem's sunset tonight: 8:18 p.m. (Salem Airport data for Thursday, August 14th: High 80?F; Rainfall: Tr.) (Maximum Ventilation Index expected today: 60) EXTENDED DISCUSSION: A dry and stable westerly flow aloft should clear skies by Saturday afternoon with temperatures warming to slightly above average. A very weak upper-level trough will likely turn the flow aloft southwesterly on Sunday, which should provide additional slight warming under mostly sunny skies. The flow aloft is forecast to turn southerly by Monday, as the trough moves onshore. That may generate scattered afternoon thundershowers over the Cascades. Long-range computer models show a WNW flow aloft bringing increasing onshore flow and cooler temperatures beginning next Tuesday. That may create burning opportunities, if fields remain dry. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 33792 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Aug 15 11:45:30 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 15 Aug 2014 11:45:30 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT FRI AUG 15, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: A persistent upper-level low-pressure system, centered over SE Washington at midday, will continue to slowly migrate to the NE this afternoon. Clouds still cover most of Washington and northern Oregon, but a drier westerly flow aloft should slowly begin to clear skies this afternoon across NW Oregon. An extended period of favorable burning conditions appears likely today. Residual cool air aloft and daytime heating will combine to yield high mixing heights along with gradually increasing onshore flow. An 11 a.m. PIBAL confirmed southerly transport winds, which should slowly veer to SW, then west, and eventually WNW, over the course of the day. The next PIBAL is scheduled for noon. TODAY'S FORECAST: Partial clearing this afternoon. Salem's high temperature today will be near 80?F (average is 83?F). Relative humidity: Dropping below 65% by noon and to near 45% by 5 p.m. Surface winds: S 3-8 mph; veering to the SW then WNW 5-10 mph this afternoon. Transport winds: S 4-8 mph; veering to SW then WNW 8-14 mph this afternoon. Mixing height: Rising to above 5000 feet by 5 p.m. Salem's sunset tonight: 8:18 p.m. (Salem Airport data for Thursday, August 14th: High 80?F; Rainfall: Tr.) (Maximum Ventilation Index expected today: 70) EXTENDED DISCUSSION: A dry and stable westerly flow aloft should clear skies by Saturday afternoon with temperatures warming to slightly above average. A very weak upper-level trough will back the winds aloft to southwesterly on Sunday, which should provide additional slight warming under mostly sunny skies. The flow aloft may turn briefly southerly on Monday, as the trough gets kicked onshore by a weather system cutting across SW Canada. That may generate scattered afternoon thundershowers across SW Oregon and along the Cascades. Long-range computer models show the polar jet stream becoming more active; forcing an early autumn-like trough into the region from the Gulf of Alaska. Beginning next Tuesday, increasing onshore flow and progressively cooler air aloft may provide burning opportunities but also a chance of showers. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Aug 18 08:47:03 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 18 Aug 2014 08:47:03 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT MON AUG 18, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from 2 to 4 p.m. with a 50 acre limit. WEATHER DISCUSSION: Flat upper level ridge resides to the north of the state with a weak upper low to the south. This low has been providing thunderstorms over mainly the east side of the Cascades and will do so again today. Satellite picture shows clear skies with the marine layer penetrating into the Coast Range this morning. Some wildfire smoke has drifted up from California again but is not nearly smoky as has been in previous weeks. Morning sounding shows low level wind flow from the NNE at 10 - 15 mph up to about 5000 ft. Morning surface chart shows high pressure to the north and low pressure south. Current pressure gradients are +2.6 mb from Newport to Salem and -0.5 mb from Salem to Redmond. Upper level ridge will gradually weaken today as well as the low to the south. Expect one more day of hot weather before cooling begins tomorrow. Mixing will slowly lift this morning into the afternoon with maximum mixing height of about 4000 ft today. Pressure gradients should become a little more favorable this afternoon but afternoon thunderstorm development along the Cascades will be problematic for burning. In addition, wind appears it will maintain a northerly flow through the day with a weak influx of marine not arriving until evening. TODAY'S FORECAST: Sunny and hot with some haze from wildfire smoke. Salem's high temperature today will be near 92 degrees (average is 82). Relative humidity: Will drop below 60 percent around 10 a.m. and drop to 30 - 35 percent by 4 p.m. Surface winds: N at 4 - 8 mph this morning increasing to N at 8 - 15 mph this afternoon and NNW at 8 - 12 mph this evening. Transport winds: N to NNE at 8 - 12 mph this morning becoming northerly at 10 - 15 mph this afternoon and NNW to N at 10 - 15 mph this evening. Mixing height: Rising to 2500 ft around 11 a.m., rising to 3000 ft by 2 p.m. and 4000 ft by 5 p.m. Salem's sunset tonight: 8:13 p.m. (Salem Airport data for Sunday, Aug 17th: High 92?F; Rainfall: .00") (Maximum Ventilation Index expected today: 60) EXTENDED DISCUSSION: Upper level trough drops southward over the state tomorrow bringing in cooler air aloft and at the surface as a minor marine push moves into the Willamette Valley on Tuesday. Expect afternoon winds NW'erly at 10 - 15 mph. Cooler, NW'erly flow will remain over the region through Wednesday and Thursday before turning more northerly on Friday. High temperatures lower into the 80s on Tuesday and into the 70s through the remainder of the week. Following the Tuesday marine push, expect some morning low clouds with afternoon clearing. No rain is expected. Burning opportunities should be favorable most of the extended period. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Nick.doc Type: application/msword Size: 34816 bytes Desc: Silverton Hills AM Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Aug 18 11:51:17 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 18 Aug 2014 11:51:17 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast - Noon Update Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT MON AUG 18, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from 2 to 4 p.m. with a 50 acre limit. WEATHER DISCUSSION: Flat upper level ridge resides to the north of the state with a weak upper low to the south. This low has been providing thunderstorms over mainly the east side of the Cascades and will do so again today. Currently, skies are clear with the marine layer mostly along the coast. Some wildfire smoke has drifted up from California but is not nearly as smoky as has been in previous weeks. Morning surface chart shows high pressure to the northwest and low pressure to the south. Current pressure gradients are +2.9 mb from Newport to Salem and -0.6 mb from Salem to Redmond. Upper level ridge will gradually weaken today as well as the low to the south. Expect one more day of hot weather before cooling begins tomorrow. Mixing will slowly lift into the afternoon with maximum mixing height of about 4000 ft today. Pressure gradients should become a little more favorable this afternoon but later afternoon thunderstorm development along the Cascades will be problematic for burning. In addition, wind appears it will maintain a northerly flow through the day with a weak influx of marine air not arriving until evening. TODAY'S FORECAST: Sunny and hot with some haze from wildfire smoke. Salem's high temperature today will be near 92 degrees (average is 82). Relative humidity: Will drop to 30 - 35 percent by 4 p.m. Surface winds: N at 8 - 15 mph this afternoon and NNW at 8 - 12 mph this evening. Transport winds: Northerly at 10 - 15 mph this afternoon and NNW to N at 10 - 15 mph this evening. Mixing height: Rising to 3000 ft around 2 p.m. and 4000 ft by 5 p.m. Salem's sunset tonight: 8:13 p.m. (Salem Airport data for Sunday, Aug 17th: High 92?F; Rainfall: .00") (Maximum Ventilation Index expected today: 60) EXTENDED DISCUSSION: Upper level trough drops southward over the state tomorrow bringing in cooler air aloft and at the surface as a minor marine push moves into the Willamette Valley on Tuesday. Expect afternoon winds NW'erly at 10 - 15 mph. Cooler, NW'erly flow will remain over the region through Wednesday and Thursday before turning more northerly on Friday. High temperatures lower into the 80s on Tuesday and into the 70s through the remainder of the week. Following the Tuesday marine push, expect some morning low clouds with afternoon clearing. No rain is expected. Burning opportunities should be favorable most of the extended period. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Nick.doc Type: application/msword Size: 34816 bytes Desc: Silverton Hills Midday Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Aug 19 08:53:52 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 19 Aug 2014 08:53:52 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT TUE AUG 19, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: A dry cold front moved across NW Oregon early this morning and had pushed east of The Dalles by mid-morning. Marine low clouds blanket most of the coastline and are banked up against the coast range. However, they have not penetrated into the Willamette Valley. Increasing onshore flow is cooling the air aloft and will lead to more seasonal temperatures today. Favorable burning conditions are likely today. Cooling aloft and daytime heating should yield high afternoon mixing heights, and increasing onshore flow will maintain a significant westerly component to the transport winds. The lack of marine clouds this morning will also help to maintain favorable pressure gradient-stacking. However, onshore flow may strengthen enough late this afternoon to begin inhibiting smoke plume development. TODAY'S FORECAST: Partly cloudy and cooler. Salem's high temperature today will be near 85?F (average is 82?F). Relative humidity: Dropping below 60% by 11 a.m. and to near 40% by 5 p.m. Surface winds: W 4-8 mph this morning; NW 5-15 mph this afternoon. Transport winds: WNW 10 mph this morning; NW 10-18 mph this afternoon. Mixing height: Rising to 3000 feet near 11 a.m. and above 5000 feet by 2 p.m. Salem's sunset tonight: 8:11 p.m. (Salem Airport data for Monday, August 18th: High 93?F; Rainfall: .00") (Maximum Ventilation Index expected today: 120) EXTENDED DISCUSSION: A cool NW flow aloft will continue through the week, with a gradually strengthening upper-level trough over the Pacific Northwest. Temperatures should generally cool to 5-10 degrees below average with varying amounts of morning marine clouds and partly cloudy afternoons. Additional burning opportunities are likely, with generally NW transport winds and good afternoon mixing. However, pressure gradient-stacking may become more of an issue, as the marine layer deepens across the valley. There is also a risk of light showers later in the week. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Aug 19 11:48:30 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 19 Aug 2014 11:48:30 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT TUE AUG 19, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Westerly flow aloft directed a dry cold front, with mainly middle and high clouds, across NW Oregon early this morning. Skies have cleared across the interior of NW Oregon, with marine low clouds persisting along the northern and central coast. Cooler air aloft will knock 5-8 degrees off of today's valley high temperatures, compared to Monday, even with sunny skies. Onshore pressure gradients are increasing and favorably "stacked" to keep smoke elevated. An 11 a.m. PIBAL showed light westerly winds in the mixing layer; sheering to the NNW at and above the mixing height of approximately 3000 feet. Another PIBAL is scheduled for noon. Favorable onshore pressure gradients should persist today with good afternoon mixing and predominantly NW transport winds. Low-level winds may strengthen enough later this afternoon to inhibit good vertical plume development. TODAY'S FORECAST: Sunny but cooler. Salem's high temperature today will be near 85?F (average is 82?F). Relative humidity: Dropping to near 40% by 5 p.m. Surface winds: W 2-6 mph; becoming NW 5-15 mph this afternoon. Transport winds: W 5 mph; becoming NW 8-18 mph this afternoon. Mixing height: Above 3000 feet; rising to near 5000 feet by 2 p.m. Salem's sunset tonight: 8:11 p.m. (Salem Airport data for Monday, August 18th: High 93?F; Rainfall: .00") (Maximum Ventilation Index expected today: 120) EXTENDED DISCUSSION: A cool NW flow aloft will continue through the week, as an upper-level trough slowly strengthens over the Pacific Northwest. Temperatures should generally cool to about 5-10 degrees below average with varying amounts of morning marine clouds and partly cloudy afternoons. The combination of high afternoon mixing heights and NW transport winds should provide additional burning opportunities. Pressure gradient-stacking may be an issue at times, as the marine layer deepens across the valley. There is also a risk of light showers later in the week. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Aug 20 08:54:07 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 20 Aug 2014 08:54:07 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:50 AM PDT WED AUG 20, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from 11 a.m. until 1 p.m. with a 50 acre limit. WEATHER DISCUSSION: A moderate marine push into western Oregon overnight produced a fairly solid deck of marine low clouds across the Willamette Valley this morning, with areas of light drizzle. The cooler and moist marine air will knock about 10 degrees off of valley high temperatures today, even with afternoon clearing. Mixing heights and transport winds should be favorable for burning again today. However, negative pressure gradient-stacking, this morning, will need to be balanced by daytime heating, before smoke will stay elevated. That is not likely to happen until at least mid-afternoon. Like yesterday, low-level winds may strengthen enough late this afternoon to inhibit good vertical plume development. TODAY'S FORECAST: Cloudy this morning with areas of light drizzle. Afternoon clearing. Salem's high temperature today will be near 79?F (average is 82?F). Relative humidity: Dropping below 60% by 11 a.m. and to near 35% by 5 p.m. Surface winds: NW 5-10 mph this morning; NW 5-15 mph this afternoon. Transport winds: NW 10 mph this morning; NW 10-18 mph this afternoon. Mixing height: Rising to near 3000 feet at 11 a.m.; to 5000 feet by 2 p.m. Salem's sunset tonight: 8:10 p.m. (Salem Airport data for Tuesday, August 19th: High 89?F; Rainfall: .00") (Maximum Ventilation Index expected today: 110) EXTENDED DISCUSSION: A cool NW flow aloft will continue through the week, as an upper-level trough slowly strengthens over the Pacific Northwest. Temperatures should remain a few degrees below average with varying amounts of morning marine clouds. The combination of high afternoon mixing heights and NW transport winds may provide additional burning opportunities. However, gradient-stacking will continue to be a limiting factor for burning. There is also an increased risk of light showers by Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Aug 20 11:53:45 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 20 Aug 2014 11:53:45 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT WED AUG 20, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from now until 1 p.m. with a 50 acre limit. WEATHER DISCUSSION: Marine low clouds began to clear late this morning and will give way to progressively more sunshine this afternoon. However, cooler air aloft will likely cap valley high temperatures in the upper 70s. Mixing heights and transport winds should be favorable for burning again this afternoon, but negative pressure gradient-stacking will need to be balanced by daytime heating. That is unlikely before 2 p.m. Today's first PIBAL is scheduled for 1 p.m. Like yesterday, low-level winds may strengthen enough later this afternoon to inhibit good vertical plume development. TODAY'S FORECAST: Becoming partly cloudy this afternoon. Salem's high temperature today will be near 79?F (average is 82?F). Relative humidity: Dropping to near 35% by 5 p.m. Surface winds: NW 5-10 mph; becoming NW 10-15 mph late this afternoon. Transport winds: NW 10 mph; becoming NW 15 mph late this afternoon. Mixing height: Rising to near 5000 from 2 p.m. through 5 p.m. Salem's sunset tonight: 8:10 p.m. (Salem Airport data for Tuesday, August 19th: High 89?F; Rainfall: .00") (Maximum Ventilation Index expected today: 100) EXTENDED DISCUSSION: A cool NW flow aloft will continue through the week, as an upper-level trough slowly strengthens over the Pacific Northwest. Temperatures should remain a few degrees below average with varying amounts of morning marine clouds. The combination of high afternoon mixing heights and NW transport winds may provide burning opportunities; limited primarily by gradient-stacking. There is also a threat of light showers by Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 33792 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Aug 21 08:58:04 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 21 Aug 2014 08:58:04 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT THU AUG 21, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from 11 a.m. until 1 p.m. with a 50 acre limit. WEATHER DISCUSSION: Northwesterly flow aloft is spreading some high clouds across NW Oregon this morning. Low-level onshore flow is weaker, compared to yesterday morning, with only patchy marine clouds in the Willamette Valley. That allowed valley temperatures to drop into the upper 40s and low 50s. An upper-level disturbance will slide southward along the British Columbia coastline today, turning the flow aloft more westerly and increasing the low-level onshore flow. Cooling aloft will combine with daytime heating to lift mixing heights to at or above 6000 feet by late this afternoon with WNW transport winds likely providing very favorable burning conditions. A significant "Marine Push" is expected tonight with areas of drizzle possible Friday morning throughout the valley. TODAY'S FORECAST: Mostly sunny. Salem's high temperature today will be near 79?F (average is 82?F). Relative humidity: Dropping below 60% by 11 a.m. and to near 35% by 5 p.m. Surface winds: NW 3-6 mph this morning; WNW 5-10 mph this afternoon. Transport winds: NW 5-10 mph this morning; WNW 10-15 mph this afternoon. Mixing height: Rising to near 3000 feet at 11 a.m.; to 6000 feet by 5 p.m. Salem's sunset tonight: 8:08 p.m. (Salem Airport data for Wednesday, August 20th: High 79?F; Rainfall: .00") (Maximum Ventilation Index expected today: 100) EXTENDED DISCUSSION: An upper-level trough will move over the region on Friday. After areas of morning drizzle, expect partial afternoon clearing with a threat of showers. High temperatures will likely remain in the 70s. The upper-level trough is forecast to move east of the state over the weekend with a dry northwesterly flow aloft clearing skies and warming temperatures back into the mid to upper 80s. Expect continued dry weather with a slight cool-down early next week. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Aug 21 11:53:59 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 21 Aug 2014 11:53:59 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT THU AUG 21, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is allowed from now until 1 p.m. with a 50 acre limit. WEATHER DISCUSSION: Middle and high clouds continue to stream across northern Oregon at midday, in response to an increasing northwesterly flow aloft. An upper-level disturbance, sliding southward along the British Columbia coastline, will slowly turn the flow aloft more westerly this afternoon; setting up quite favorable burning conditions. Mixing heights will rise to above 3000 feet, once surface temperatures warm into the low-70s and should rise to near 5000 feet by 2 p.m. An 11 a.m. PIBAL showed light SW winds below about 3000 feet; abruptly veering to NW above that level. Winds are expected to turn more westerly at all transport levels this afternoon. A significant surge of marine air into the valley tonight should be sufficient to evacuate any residual smoke. TODAY'S FORECAST: Mostly sunny. Salem's high temperature today will be near 79?F (average is 82?F). Relative humidity: Dropping to near 35% by 5 p.m. Surface winds: WNW 5-10 mph. Transport winds: WNW 10-15 mph this afternoon. Mixing height: Rising above 5000 feet from 2 p.m. through 6 p.m. Salem's sunset tonight: 8:08 p.m. (Salem Airport data for Wednesday, August 20th: High 79?F; Rainfall: .00") (Maximum Ventilation Index expected today: 100) EXTENDED DISCUSSION: An upper-level trough will move over the region on Friday. After areas of morning drizzle, expect partial afternoon clearing with a threat of showers. High temperatures will likely remain in the 70s. The upper-level trough is forecast to move east of the state over the weekend with a dry northwesterly flow aloft clearing skies and warming temperatures back into the mid to upper 80s. The updated long-range guidance is now building a fairly strong upper-level ridge over the region early next week, which would warm valley temperatures back into the 90s with generally north to NE transport winds. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Aug 22 08:45:35 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 22 Aug 2014 08:45:35 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT FRI AUG 22, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: A "Marine Push" is in progress across western Oregon...initiated by a cool but relatively dry upper-level trough that came onshore overnight and will remain over Washington and Oregon today. Low clouds cover most of the Willamette Valley at mid-morning and will likely continue to expand in coverage and depth, before giving way to partly cloudy skies this afternoon. With a cool upper-level trough over the region, daytime heating will allow mixing to the top of the marine layer this afternoon, which is about 6000 feet deep. However, the air mass may become unstable enough to trigger thunderstorm development over the Cascades. The deep marine layer should also create some gradient-stacking issues, and transport winds will maintain a significant northerly component. TODAY'S FORECAST: Cloudy this morning with possible areas of drizzle. Partly cloudy this afternoon. Risk of afternoon thunderstorms over the Cascades. Salem's high temperature today will be near 79?F (average is 82?F). Relative humidity: Dropping below 60% by 11 a.m. and to near 35% by 5 p.m. Surface winds: Light this morning; NNW 5-12 mph this afternoon. Transport winds: N 3-6 mph this morning; NNW 10-15 mph this afternoon. Mixing height: Rising to near 3000 feet at noon; to 6000 feet by 5 p.m. Salem's sunset tonight: 8:06 p.m. (Salem Airport data for Thursday, August 21st: High 82?F; Rainfall: .00") (Maximum Ventilation Index expected today: 100) EXTENDED DISCUSSION: The upper-level trough currently over the region is forecast to move over the Rockies this weekend. A dry northwesterly flow aloft will clear skies and warm temperatures back into the mid-80s. A strengthening upper-level ridge may warm valley temperatures into the low-90s by the middle of next week, with generally north to NE transport winds. The ridge is expected to give way to a fairly strong upper-level trough late next week, which could provide burning opportunities. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Aug 22 11:49:02 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 22 Aug 2014 11:49:02 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT FRI AUG 22, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: A cool but relatively dry upper-level trough moved onshore last night, initiating a moderate "marine push" and driving low clouds across much of the Willamette Valley early this morning. Skies had cleared significantly by midday, but the upper-level trough will remain over the region today. With cool air aloft, mixing depths should expand to the top of the marine layer, about 6000 feet, once surface temperatures warm into the mid-70s. However, the air mass may become unstable enough for shower and thundershower development, especially over the Cascades, which can cause unwanted down-mixing of smoke. In addition, increasing NNE winds, just above the mixing layer, may inhibit late-day smoke evacuation. TODAY'S FORECAST: Partly cloudy and cooler this afternoon. Risk of afternoon showers or thunderstorms, mainly over the Cascades. Salem's high temperature today will be near 79?F (average is 82?F). Relative humidity: Dropping to near 35% by 5 p.m. Surface winds: NE 4-7 mph; backing to NNW 5-12 mph this afternoon. Transport winds: NNE 5-8 mph; backing to NNW 10-15 mph this afternoon. Mixing height: Rising to near 6000 feet by 5 p.m. Salem's sunset tonight: 8:06 p.m. (Salem Airport data for Thursday, August 21st: High 82?F; Rainfall: .00") (Maximum Ventilation Index expected today: 100) EXTENDED DISCUSSION: The upper-level trough over the region is forecast to move eastward, to over the Rockies, this weekend. A dry northwesterly flow aloft will clear skies and warm temperatures back into the low-to-mid-80s with mostly north winds. A building upper-level ridge may warm valley temperatures to near 90?F by next Tuesday, with north to NE transport winds. The ridge should give way to increasing southwesterly flow aloft next Wednesday through Friday, which will begin a cooling trend and possibly provide burning opportunities. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Aug 25 08:47:43 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 25 Aug 2014 08:47:43 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT MON AUG 25, 2014 BURN ADVISORY: Fire Marshal conditions are possible this afternoon due to humidity's below 30 percent and wind gusts exceeding 15 mph. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level ridge is nosing into the state today as a trough exits to the east. Skies are clear over the area with marine low clouds remaining along the coast with no inland penetration. Morning sounding shows low level wind flow from the NNE to E at 5 - 15 mph up to 5000 ft. Morning surface chart shows high pressure to the north and low pressure to the south. Current pressure gradients are +1.1 mb from Newport to Salem and -1.6 mb from Salem to Redmond. Upper level ridge will gradually move into the region today bringing northerly flow and warmer temperatures. Mixing will remain below 2500 ft this morning but heating during the late morning to early afternoon will break the inversion and lift the mixing height above 5000 ft by 2 p.m. Surface high pressure will remain to the north with a thermal trough remaining over the southern part of the state. This will likely keep gradients negatively stacked and not make for good burning conditions. TODAY'S FORECAST: Sunny and very warm. Salem's high temperature today will be near 89 degrees (average is 81). Relative humidity: Will drop below 60 percent around 9 a.m. and drop below 30 percent by 3 p.m. Surface winds: N to NE at 5 - 10 mph this morning increasing to N to NNE at 10 - 18 mph this afternoon. Transport winds: NNE to NE at 8 - 15 mph this morning becoming N to NNE at 13 - 18 mph this afternoon and evening. Mixing height: Rising to 2500 ft around noon, rising above 5000 ft by 2 p.m. Salem's sunset tonight: 8:01 p.m. (Salem Airport data for Sunday, Aug 24th: High 85?F; Rainfall: .00") (Maximum Ventilation Index expected today: 100+) EXTENDED DISCUSSION: Upper level ridge builds over the state on Tuesday then flattens and remains in place until the end of the week. Expect clear skies and fairly hot afternoon temperatures, reaching into the lower to mid-90s. Low-level wind flow will likely remain northerly through Thursday with maybe a weak influx of marine air during the early evening hours. Burn opportunities look limited until Friday when a trough approaches and potentially brings a marine push Friday afternoon. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Nick.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills AM Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Mon Aug 25 11:48:27 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Mon, 25 Aug 2014 11:48:27 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast - Noon Update Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT MON AUG 25, 2014 BURN ADVISORY: Fire Marshal conditions are possible this afternoon due to humidity's below 30 percent and wind gusts exceeding 15 mph. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level ridge is nosing into the state today as a trough exits to the east. Skies are clear over the area with marine low clouds dissipating and moving away from the coast. Morning surface chart shows high pressure to the north with the thermal trough building up from the south. Current pressure gradients are +1.4 mb from Newport to Salem and -2.0 mb from Salem to Redmond. Upper level ridge will gradually move into the region today bringing northerly flow and warmer temperatures. Mixing will lift above 5000 ft by 2 p.m. Surface pressure pattern remains on track with high pressure remaining to the north and the thermal trough building northward. This will likely keep gradients negatively stacked and not make for good burning conditions. TODAY'S FORECAST: Sunny and very warm. Salem's high temperature today will be near 89 degrees (average is 81). Relative humidity: Will drop below 30 percent by 3 p.m. Surface winds: N to NNE at 10 - 18 mph this afternoon. Transport winds: N to NNE at 13 - 18 mph this afternoon and evening. Mixing height: Rising above 5000 ft by 2 p.m. Salem's sunset tonight: 8:01 p.m. (Salem Airport data for Sunday, Aug 24th: High 85?F; Rainfall: .00") (Maximum Ventilation Index expected today: 100+) EXTENDED DISCUSSION: Upper level ridge builds over the state on Tuesday then flattens and remains in place until the end of the week. Expect clear skies and fairly hot afternoon temperatures, reaching into the low to mid-90s. Low-level wind flow will likely remain northerly through Thursday with maybe a weak influx of marine air during the early evening hours. Burn opportunities look limited until Friday when a trough approaches and potentially brings a marine push Friday afternoon. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Nick.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Aug 26 08:47:20 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 26 Aug 2014 08:47:20 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:45 AM PDT TUE AUG 26, 2014 BURN ADVISORY: Fire Marshal conditions may be reached this afternoon due to humidity's below 30 percent and temperature reaching 95 degrees. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level ridge continues to build over the state today. Skies are clear this morning with marine low clouds along the coast with little inland penetration. Morning sounding shows low level wind flow from the NNE to NE at 5 - 15 mph up to 3000 ft, and light and variable above. A thermal trough is extending into the Willamette Valley with pressure gradients +1.6 mb from Newport to Salem and -3.0 mb from Salem to Redmond. Upper level ridge will continue to build into the region today and gradually flatten later today and tonight. Mixing will remain below 2500 ft this morning but heating during the late morning to early afternoon will break the inversion and lift the mixing height above 5000 ft by 4 p.m. Thermal trough will likely remain over the Willamette Valley with onshore gradient increasing from the coast to the valley and offshore gradient decreasing from the valley to central Oregon. Expect continued northerly flow today with a light marine air influx most likely moving in during the early evening. Burn opportunities will be marginal at best. TODAY'S FORECAST: Sunny and very warm. Salem's high temperature today will be near 93 degrees (average is 81). Relative humidity: Has dropped below 60 percent and will drop below 30 percent by 2 p.m. Surface winds: N to NE at 3 - 8 mph this morning increasing to northerly at 6 - 12 mph this afternoon. Transport winds: N to NNE at 5 - 12 mph this morning becoming generally northerly at 5 - 10 mph this afternoon and NW to NNW at 8 -15 mph this evening. Mixing height: Rising to 2500 ft around noon, rising above 5000 ft by 4 p.m. Salem's sunset tonight: 8:00 p.m. (Salem Airport data for Monday, Aug 25th: High 92?F; Rainfall: .00") (Maximum Ventilation Index expected today: 60) EXTENDED DISCUSSION: Flat upper level ridge will remain over the state on Wednesday and Thursday before an upper level trough approaches the state Thursday night and Friday. Expect clear skies and very warm afternoon temperatures. It's possible that marine air will move into the Willamette Valley Thursday afternoon and give a possible burn opportunity but the main marine push is still likely to be on Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Nick.doc Type: application/msword Size: 35328 bytes Desc: Silverton Hills AM Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Tue Aug 26 11:48:24 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Tue, 26 Aug 2014 11:48:24 -0700 Subject: [willamette-fcst] Willamette Valley Field Burning Forecast - Noon Update Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:45 AM PDT TUE AUG 26, 2014 BURN ADVISORY: Fire Marshal conditions may be reached this afternoon due to humidity's below 30 percent and temperature reaching 95 degrees. Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Upper level ridge continues to build over the state today. Late morning surface map shows the thermal trough remaining in the Willamette Valley with pressure gradients +2.0 mb from Newport to Salem and -2.9 mb from Salem to Redmond. Surface winds are mostly light northerly. Temperatures today are a couple degrees above yesterday's temperatures at this time. Upper level ridge will gradually flatten tonight and tomorrow. Mixing height will lift to 2500 ft by noon with heating breaking the temperature inversion this afternoon and lifting the mixing height above 5000 ft. Thermal trough will likely remain over the Willamette Valley with onshore gradient increasing from the coast to the valley and offshore gradient decreasing from the valley to central Oregon. Expect continued northerly flow today with a light marine air influx moving in during the early evening. TODAY'S FORECAST: Sunny and very warm. Salem's high temperature today will be near 93 degrees (average is 81). Relative humidity: Will drop below 30 percent around 1 p.m. Surface winds: Northerly at 6 - 12 mph this afternoon, turning NW'erly at 8 - 15 mph early this evening. Transport winds: Northerly at 5 - 10 mph this afternoon and NW to NNW at 8 -15 mph this evening. Mixing height: Rising above 5000 ft by 4 p.m. Salem's sunset tonight: 8:00 p.m. (Salem Airport data for Monday, Aug 25th: High 92?F; Rainfall: .00") (Maximum Ventilation Index expected today: 60) EXTENDED DISCUSSION: Flat upper level ridge will remain over the state on Wednesday and Thursday before an upper level trough approaches the state Thursday night and Friday. Expect clear skies and very warm afternoon temperatures. It's possible that marine air will move into the Willamette Valley Thursday afternoon and give a possible burn opportunity but the main marine push is still likely to be on Friday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Nick Yonker ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Nick.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Nick.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Aug 27 08:57:29 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 27 Aug 2014 08:57:29 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT WED AUG 27, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: The strong upper-level ridge over Oregon is beginning to flatten, as weak weather systems move across SW Canada. That has turned the winds above 8000 feet from northeasterly to westerly. However, below 8000 feet, this morning's sounding over Salem looks almost identical to Tuesday morning. Valley temperatures are also very similar to 24 hours ago. A surface thermal trough is over western Oregon this morning, with onshore flow from Newport to Salem and offshore flow from Redmond to Salem. Like yesterday, warm air aloft will keep mixing heights under 3000 feet until surface temperatures reach about 87?F (around 2 p.m.). One possible change today is that the thermal trough may shift east of the Cascades this afternoon; allowing some marine air to seep into the Willamette Valley. If that happens, it would cap high temperatures in the low 90s (a few degrees cooler than on Tuesday) and could turn transport winds northwesterly. TODAY'S FORECAST: Sunny and warm. Salem's high temperature today will be near 91?F (average is 81?F). Relative humidity: Dropping below 50% by 11 a.m. and to near 25% by 5 p.m. Surface winds: N 3-6 mph this morning; N-NW 4-10 mph this afternoon. Transport winds: NNE 4-8 mph this morning; N-NW 5-10 mph this afternoon. Mixing height: Rising to near 3000 feet at 2 p.m.; to 4000 feet by 5 p.m. Salem's sunset tonight: 7:58 p.m. (Salem Airport data for Tuesday, August 26th: High 95?F; Rainfall: .00") (Maximum Ventilation Index expected today: 40) EXTENDED DISCUSSION: The upper-level ridge will further flatten on Thursday with increasing westerly flow above about 6000 feet. That should force the surface thermal trough into eastern Oregon with increasing onshore flow cooling Willamette Valley temperatures back into the mid-80s. Transport winds may turn northwesterly enough to provide an afternoon burning opportunity. A strengthening west-southwesterly flow aloft will significantly increase the onshore flow on Friday, with morning marine clouds likely and valley temperatures cooling into the upper 70s. Cooling aloft will improve mixing. If morning marine clouds are not too persistent, creating poor gradient-stacking conditions, onshore transport winds will be favorable for burning. An upper-level trough is forecast to move across Oregon Friday night with a cool NW flow aloft on Saturday. This system looks mostly dry, but some morning drizzle or a few light showers are possible, with temperatures cooling to the mid-70s. A mostly dry northwesterly flow aloft is forecast to continue through early next week, with varying amounts of morning clouds, afternoon sunshine, and slightly below average temperatures. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34816 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Wed Aug 27 11:57:42 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Wed, 27 Aug 2014 11:57:42 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:55 AM PDT WED AUG 27, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: The strong upper-level ridge over Oregon is flattening in response to weather systems cutting across SW Canada. That has turned the winds aloft light westerly. However, with clear skies and a surface thermal trough over western Oregon, temperatures are close to where they were 24 hours ago. Transport winds were northeasterly this morning and will be monitored with PIBALS this afternoon. Like yesterday, warm air aloft will keep mixing heights under 3000 feet until surface temperatures reach about 87?F (around 2 p.m.). A possible eastward shift of the thermal trough, into central Oregon, could turn transport winds light northwesterly this afternoon. If that happens, it would likely cap temperatures a few degrees cooler than on Tuesday and could provide a limited burning opportunity. TODAY'S FORECAST: Sunny and warm. Salem's high temperature today will be near 91?F (average is 81?F). Relative humidity: Dropping to near 25% by 5 p.m. Surface winds: NNW 3-6 mph; increasing to 5-10 mph this afternoon. Transport winds: possibly becoming NNW 5-12 mph this afternoon. Mixing height: Rising to near 3000 feet at 2 p.m.; to 4000 feet by 5 p.m. Salem's sunset tonight: 7:58 p.m. (Salem Airport data for Tuesday, August 26th: High 95?F; Rainfall: .00") (Maximum Ventilation Index expected today: 40) EXTENDED DISCUSSION: The upper-level ridge will further flatten on Thursday with increasing westerly flow above about 6000 feet. That should force the surface thermal trough into eastern Oregon with increasing onshore flow cooling Willamette Valley temperatures back into the mid-80s. Transport winds may turn northwesterly enough to provide an afternoon burning opportunity. A strengthening west-southwesterly flow aloft will significantly increase the onshore flow on Friday, with morning marine clouds likely and valley temperatures cooling into the upper 70s. Cooling aloft will improve mixing. If morning marine clouds are not too persistent, creating poor gradient-stacking conditions, onshore transport winds will be favorable for burning. An upper-level trough is forecast to move across Oregon Friday night with a cool NW flow aloft on Saturday. This system looks mostly dry, but some morning drizzle or a few light showers are possible, with temperatures cooling to the mid-70s. A mostly dry northwesterly flow aloft is forecast to continue through early next week, with varying amounts of morning clouds, afternoon sunshine, and slightly below average temperatures. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34816 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Aug 28 08:56:41 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 28 Aug 2014 08:56:41 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT THU AUG 28, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: The strong upper-level ridge over Oregon is continuing to flatten in response to weather systems cutting across SW Canada. Westerly winds aloft have increased since yesterday; finally forcing the surface thermal trough into central Oregon. Onshore flow is slowly increasing across NW Oregon this morning. Marine clouds cover much of the coast and have made their way up the Columbia River into the Portland area. The sounding over Salem this morning showed several degrees of cooling below 6000 feet, but skies have remained mostly clear across the central and southern Willamette Valley. Expect mostly sunny skies today, with the southern edge of a dry cold front likely dragging some middle and high clouds across NW Oregon in the afternoon. With cooler air aloft, mixing heights should climb to near 3000 feet around noon, when surface temperatures reach 80?F, and to near 5000 feet by late this afternoon. Increasing onshore flow may turn transport winds enough northwesterly to create a burning opportunity. TODAY'S FORECAST: Mostly sunny but cooler. Salem's high temperature today will be near 85?F (average is 81?F). Relative humidity: Dropping to 50% around 11 a.m. and to near 35% by 5 p.m. Surface winds: NNW 3-6 mph this morning; NNW 5-10 mph this afternoon. Transport winds: N 5-10 mph this morning; NNW 8-15 mph this afternoon. Mixing height: Rising to near 3000 feet at noon and to 5000 feet by 5 p.m. Salem's sunset tonight: 7:56 p.m. (Salem Airport data for Wednesday, August 27th: High 93?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: Marine clouds may penetrate into much of the Willamette Valley Friday morning, with some negative pressure-gradient-stacking. A stronger dry cold front is forecast to approach the coastline Friday afternoon, with a strengthening west-southwesterly flow aloft. Additional cooling aloft and increasing WNW transport winds should make for very favorable burning conditions, once onshore pressure gradients are "balanced out." An upper-level trough is forecast to move across Oregon Friday night with a cool NW flow aloft Saturday through Monday. This pattern looks mostly dry, but some morning drizzle or a light shower can't be ruled out. The main impact will be temperatures cooling to the mid-70s and good ventilation. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34816 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Thu Aug 28 11:54:04 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Thu, 28 Aug 2014 11:54:04 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:50 AM PDT THU AUG 28, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: A flattening upper-level ridge is allowing weather systems that have been sweeping across SW Canada to get progressively closer to Oregon. One such system will bring some high clouds to NW Oregon today. West winds aloft are increasing, with the surface thermal trough over central Oregon. Cooling aloft will yield higher mixing heights today, and increasing onshore flow should make for favorable pressure gradients to keep smoke elevated. However, transport winds were NNE this morning and may not turn enough onshore to allow for much burning. The first PIBAL is scheduled for noon. TODAY'S FORECAST: Mostly sunny but cooler. Salem's high temperature today will be near 85?F (average is 81?F). Relative humidity: Dropping to near 35% by 5 p.m. Surface winds: NNE 4-8 mph; possibly NNW 5-10 mph this afternoon. Transport winds: NNE 5-10 mph; possibly NNW 8-15 mph this afternoon. Mixing height: Rising to near 5000 feet by 5 p.m. Salem's sunset tonight: 7:56 p.m. (Salem Airport data for Wednesday, August 27th: High 93?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: Marine clouds may penetrate into much of the Willamette Valley Friday morning, with some negative pressure-gradient-stacking. A stronger dry cold front is forecast to approach the coastline Friday afternoon, with a strengthening west-southwesterly flow aloft. Additional cooling aloft and increasing WNW transport winds should make for very favorable burning conditions, once onshore pressure gradients are "balanced out." An upper-level trough is forecast to move across Oregon Friday night with a cool NW flow aloft Saturday through Monday. This pattern looks mostly dry, but some morning drizzle or a light shower can't be ruled out. The main impact will be temperatures cooling to the mid-70s and good ventilation. Another dry weather system may bring favorable burning conditions around the middle of next week. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Aug 29 08:57:00 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 29 Aug 2014 08:57:00 -0700 Subject: [willamette-fcst] Silverton Hills AM Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 8:55 AM PDT FRI AUG 29, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: The upper-level ridge responsible for the sunny and warm weather this week is breaking down. A weak weather system pushed high clouds across the region Thursday afternoon; increasing the onshore flow and cooling maximum temperatures from the 90s back into the 80s. This morning's sounding over Salem showed continued cooling below 5000 feet; an indication that the marine layer is deepening. Low clouds are more extensive across NW Oregon this morning but do not completely cover the Willamette Valley. Another, slightly stronger, weather system is already spreading clouds across western Washington and the NW tip of Oregon, with some light rain falling on the northern Washington coast. This system will bring increasing middle and high clouds to the region this afternoon, with high temperatures likely falling back into the upper 70s. Very favorable conditions for burning are likely today. Additional cooling aloft and frontal forcing will promote good lifting of smoke plumes with minimal down-mixing. Transport winds should slowly veer from southwesterly late this morning to westerly in the early afternoon and northwesterly in the late afternoon. The limiting factor today will be getting enough surface heating to establish good mixing and to lower the relative humidity enough for burning. That could happen as early as 11 a.m. TODAY'S FORECAST: Areas of morning clouds; increasing middle and high clouds in the afternoon. Salem's high temperature today will be near 78?F (average is 81?F). Relative humidity: Dropping below 65% by 11 a.m. and to below 50% by 2 p.m. Surface winds: SW 2-6 mph a.m.; W 5-10 mph early p.m.; NW 10 mph late p.m. Transport winds: SW 5 mph a.m.; W 10 mph early p.m.; NW 15 mph late p.m. Mixing height: Rising to near 3000 feet by noon and to 5000 feet by 2 p.m. Salem's sunset tonight: 7:54 p.m. (Salem Airport data for Thursday, August 28th: High 87?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: A mostly dry upper-level trough is forecast to move across Oregon tonight, which will aid in evacuating any smoke through the Cascades. A cool NW flow aloft will set up Saturday through Monday. This pattern looks mostly dry, but some morning drizzle or light showers can't be ruled out, especially on Saturday. The main impact will be below average temperatures, with highs staying in 70s. Another mostly dry weather system may bring favorable burning conditions next Tuesday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills AM Forecast_Pete.doc Type: application/msword Size: 34816 bytes Desc: Silverton Hills AM Forecast_Pete.doc URL: From willamette-fcst at listsmart.osl.state.or.us Fri Aug 29 11:57:52 2014 From: willamette-fcst at listsmart.osl.state.or.us (Willamette Valley Field Burning Forecast) Date: Fri, 29 Aug 2014 11:57:52 -0700 Subject: [willamette-fcst] Silverton Hills Midday Forecast_Pete.doc Message-ID: SILVERTON HILLS FIELD BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 11:55 AM PDT FRI AUG 29, 2014 BURN ADVISORY: Agricultural burning is not recommended. Prep burning is not allowed. WEATHER DISCUSSION: Moring low clouds are giving way to increasing middle and high clouds. An approaching weather system is currently bringing sprinkles to NW Washington and will spread more middle and high clouds across the region this afternoon. Increasing onshore flow and cooling aloft will likely combine to hold high temperatures below 80?F. Conditions have become very favorable for burning. An 11 a.m. PIBAL revealed mostly westerly transport winds. Cooling aloft and frontal forcing will promote good lifting of smoke plumes with minimal down-mixing. WSW transport winds should slowly veer to the NW by late afternoon. Transport winds will continue to be closely monitored today. TODAY'S FORECAST: Increasing middle and high clouds this afternoon and evening. Salem's high temperature today will be near 78?F (average is 81?F). Relative humidity: Dropping below 50% by 2 p.m. Surface winds: W 5-10 mph; veering to NW 10 mph late this afternoon. Transport winds: W 10 mph; veering to NW 15 mph late this afternoon. Mixing height: Rising to near 5000 feet by 2 p.m. Salem's sunset tonight: 7:54 p.m. (Salem Airport data for Thursday, August 28th: High 87?F; Rainfall: .00") (Maximum Ventilation Index expected today: 75) EXTENDED DISCUSSION: An upper-level trough is forecast to move across Oregon tonight, which will aid in the evacuation of smoke. A cool NW flow aloft will set up Saturday through Monday. Areas of morning drizzle are possible Saturday with a chance of light showers. Precipitation totals will range from nothing to just a few hundredths of an inch. Sunday and Monday look dry, with morning clouds giving way to partly sunny afternoons. Temperatures will top out in the mid-70s Saturday, then slowly warm to the upper-70s by Monday. An approaching weak weather system may bring favorable burning conditions next Tuesday. The National Weather Service's digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text Notes: 1. Mixing height, as used here, is the lowest height at which the potential temperature exceeds the potential temperature at the surface. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 2. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 3. Ventilation Index is the height of the mixing layer (ft) times the transport wind speed (mph) divided by 1000. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. This forecast is provided under an agreement between the Oregon Department of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For information contact ODA at 503-986-4701. To add/remove your email address from this list, please go to: http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst Pete Parsons ODF Meteorologist -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Silverton Hills Midday Forecast_Pete.doc Type: application/msword Size: 34304 bytes Desc: Silverton Hills Midday Forecast_Pete.doc URL: