[willamette-fcst] Forecast - Wednesday, February 13th, 2008
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Wed Feb 13 17:47:33 PST 2008
Daily Smoke Management Forecast
Oregon Department of Agriculture
Smoke Management Program
Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts.
Wednesday, February 13, 2008 at 4:45 pm.
Burn Advisory For Thursday, February 14, 2008:
Agricultural burning is not recommended.
Stack burning is not allowed.
A cold upper-level trough brought cooler conditions and a
few showers to Washington and Oregon today...mainly over the
mountains. Snow levels dropped to 1500 feet over Northern
Oregon and 2500 feet over Southern Oregon this morning. The
Northern Oregon Cascades received a few new inches of snow
overnight with flurries being reported as of late this
afternoon. Pass temperatures stayed in the mid to upper 20s
this afternoon with the snow level only rising to about 2000
feet. The freezing level was measured over Salem this
afternoon at just 3100 feet.
Rainfall in the valley since Tuesday evening ranged from a
trace in Eugene to a few hundredths of an inch...with the
greatest amounts in the Portland area. Up to one-quarter of
an inch of rain fell along the Northern coast. Doppler
radar showed scattered light showers continuing over
Northwest Oregon late this afternoon with valley
temperatures generally in the mid and upper 40s.
Northwesterly flow aloft will turn more northerly this
evening. That showers should rapidly taper off, with
clearing skies, after sunset. Most of the valley will drop
to near or below the freezing mark overnight with areas of
fog forming by Thursday morning.
After a cool and locally foggy start Thursday, an
upper-level ridge will quickly build over the region for a
mostly sunny and warmer afternoon. Temperatures will climb
to near normal and freezing levels will rebound to 5-6000
feet by late afternoon. Subsidence, due to the building
ridge, will warm the air aloft and make for poor ventilation
conditions over the valley. Clear skies and light winds
Thursday night will allow temperatures to drop below
freezing across much of Western Oregon.
Var 0-5 Thursday morning, N 5-10 Thursday afternoon.
N 5 Thursday morning, N 10 Thursday afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height Thursday will be near 1800 feet. Ventilation index 18.
Salem\'s high temperature Thursday will be near 50.
Minimum relative humidity will be near 52%.
Salem sunrise Thursday: 7:15 am; sunset Thursday: 5:38 pm.
A very weak front will ride over the top of the ridge of
high pressure and slide across Southern British Columbia and
Washington Friday. Some clouds will likely make it
southward into Oregon, with continued onshore flow, but it
is unlikey that rain will make it this far south. Freezing
levels will rise to near 8000 feet by Friday afternoon, and
valley temperatures will climb into the low to mid 50s.
A massive ridge of high pressure is forecast to build over
the region this weekend, which will direct storm activity
northward into Central British Columbia and bring
spring-like weather to Oregon and Washington. Freezing
levels will be near 9000 feet with increasing low-level
offshore flow leading to near record high temperatures by Sunday.
The strong upper-level ridge will shift eastward, over the
Rockies, early next week. That will allow a series of
progressively stronger Pacific storms to move into the
region. Rain should return by Tuesday afternoon with an
even stronger system forcast to bring more rain and mountain
snow late Wednesday into Thursday.
The February update to the Seasonal Climate Forecast is
available on the ODA website. You can view it by going to
and clicking on: ODA\'s Seasonal Climate Forecast in either
PowerPoint or Adobe PDF format. The current outlook goes
through May, 2008.
Tomorrow (14 Feb): Areas of Morning Fog...Becoming Mostly Sunny. 29/50
Fri (15 Feb): Partly Cloudy. 29/54
Sat (16 Feb): Sunny and Mild. 35/55
Sun (17 Feb): Sunny with Near-Record Warmth. 35/60
Mon (18 Feb): Increasing Clouds & Mild. Chance of Light Rain Late. 36/57
Tue (19 Feb): Rain Likely By Afternoon. Snow Level Near 6000 Feet. 38/54
Wed (20 Feb): Chance of Showers Early...Rain Late. Snow Level 5000 Feet. 39/54
Thu (21 Feb): Rain Likely & Cooler. Snow Level 3000 Feet. 38/48
weather at oda.state.or.us
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