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Jefferson County Smoke Management Program The Jefferson County Smoke Management Program is a cooperative effort of Jefferson County Seed Growers and the Jefferson County Rural Fire Protection District, committed to a safe, controlled agricultural field burning season that insures public safety and minimizes, to the greatest degree possible, impacts of smoke on the communities of Central Oregon.
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Forecast InformationJEFFERSON COUNTY FIELD-BURNING FORECAST OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE 10:05 AM PDT FRI SEP 23, 2011 ------------- FINAL FORECAST FOR THE 2011 FIELD-BURNING SEASON ------------- WEATHER DISCUSSION: The first day of autumn will bring a continuation of summer-like weather across the state. A persistent upper-level ridge of high pressure remains centered over the Rockies with a warm and dry southwesterly flow aloft over Oregon. The weak frontal system that spread middle and high clouds across north-central Oregon on Thursday dissipated overnight. Satellite imagery this morning shows a broad band of clouds, associated with a strong southwesterly jet stream, extending from northern Vancouver Island, British Columbia to about 450 miles west of the northern Oregon coast. With the exception of areas of wildfire smoke, skies are sunny from the Cascades eastward. This morning’s Madras aircraft sounding was nearly identical to Thursday morning; showing a very warm air mass and continued southwesterly winds aloft. At the surface, a weak thermal trough remains over southwestern Oregon with high pressure centered over southeastern Oregon. Pressure-gradients across central Oregon are very week and winds are light. The offshore frontal system is forecast to remain nearly stationary today. Sunny skies and warm air aloft will help high temperatures climb a degree or two above Thursday’s readings and to more than 10 degrees above normal. Like yesterday, south-southwesterly transport winds should make for favorable afternoon burning conditions; allowing for remaining fields to get burned. TODAY’S FORECAST: Sunny and unseasonably warm. Madras’ forecast high temperature: 89 degrees Transport winds: SSW 6-10 mph this morning; SSW 10-15 mph this afternoon. Surface winds: SE 3-5 mph this morning; becoming N 4-8 mph this afternoon.
THREE-HOURLY DATA:
11 a.m. 2 p.m. 5 p.m. 8 p.m. Temperature: 72 86 88 72 Relative Humidity: 27% 16% 15% 28% Mixing Height: 1500 3200 3500 1200 Transport Wind Direction: 190 200 210 360 Transport Wind Speed: 8 10 14 10 Surface Wind Direction: 160 200 360 010 Surface Wind Speed: 4 5 6 5
EXTENDED DISCUSSION: The flow aloft, and at transport level, will become more southerly, on Saturday, as an upper-level trough digs offshore. The southerly flow will act to depress mixing heights. Computer models are showing a slow-moving frontal system finally making it onshore Saturday night with light rain likely spreading into central Oregon by midday Sunday. Up to one-tenth of an inch of rain is possible Sunday with a stronger front bringing more than one-tenth of an inch of rain on Monday. Long-range models are inconsistent after that time, but drier weather is likely for the middle of next week.
The National Weather Service’s digital forecast is available at: http://forecast.weather.gov/MapClick.php?lat=44.68&lon=-121.14861&site=pdt&unit=0&lg=en&FcstType=tex |
