[willamette-fcst] Forecast - Wednesday, May 7th, 2008
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Wed May 7 15:40:25 PDT 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, May 7, 2008 at 4:45 pm.
Burn Advisory For Thursday, May 8, 2008:
Agricultural burning is allowed. Suggested burn times are from 8:00am until 6:30pm.
Straw stack burning is allowed from 8:00am until 6:30pm.
A thick marine layer surged into the Willamette Valley last
night in response to a dry but fairly cool upper-level
trough that moved across the region. The air mass cooled
considerably with the freezing level over Salem dropping
from 9000 feet Morning to just 4200 feet this morning. Low
clouds were extensive today across Western Oregon with areas
of drizzle. Only the extreme southern coast and
Southwestern Oregon saw sunshine.
The late-afternoon visible satellite picture showed some
breaks in the low clouds beginning to appear...mainly over the
coastal range. Temperatures were 5-10 degrees cooler today in
the valley with afternoon readings struggling to reach the mid
50s under cloudy skies.
High clouds from another weak disturbance, in the
northwesterly flow aloft, were showing up nicely on infrared
satellite imagery this afternoon, as they moved over NW
Oregon. That will help maintain the strong onshore flow
across the state overnight. Skies were mostly sunny east of
the cascades today, but cool west winds at 15-30 mph kept
temperatures in the 50s and 60s. Ontario, near the Idaho
border, was the warm spot in the state this afternoon at 71
The marine low clouds will break up this evening across
Western Oregon...only to thicken up again by Thursday
morning with areas of drizzle. Temperatures may locally
fall into the upper 30s overnight, but low 40s will be
common. East of the Cascades, fair skies will combine with
a cool air mass to allow temperatures to locally drop below
the freezing mark in wind-sheltered valleys.
Another dry but cool upper-level trough is foreast to move
onshore Thursday and across Oregon Thursday night. That
will likely keep generally cloudy skies over Western Oregon
with strong onshore flow at the surface holding temperatures
mostly in the 50s. The trough may be strong enough to
produce a few sprinkles around the state...mainly over the
mountains. The snow level will remain near 4000 feet but
little in the way of precipitation is expected.
WNW 5-8 Thursday morning, NW 8-15 Thursday afternoon.
NW 8 Thursday morning, NW 10-15 Thursday afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height Thursday will be near 5000 feet. Ventilation index 40.
Salem\'s high temperature Thursday will be near 58.
Minimum relative humidity will be near 45%.
Salem sunset tonight: 8:26pm; sunrise Thursday: 5:51am.
After a cool start to the day Friday, a weak ridge of high
pressure should bring partly sunny and warmer weather Friday
afternoon with temperatures recovering to near normal across
the Willamette Valley. A weak cold front is forecast to
approach the coastline Saturday with a chance of light rain
moving onshore by late afternoon. Temperatures will likely
climb above normal, ahead of the front, Saturday and then
drop back below normal with a chance of showers Sunday.
Showers are forecast to taper off Monday, as the upper-level
trough pushes east of the region. A warm front is forecast
to bring clouds and perhaps light rain as far south as
Northwestern Oregon Tuesday, but that may be the last threat
of rain for awhile...
The long-range computer models are still indicating the
possibility of much warmer and dry weather for the latter
half of next week...extending into the following weekend.
We could be in for a taste of summer-like weather with
strong offshore surface flow and Willamette Valley
temperatures shooting well into the 80s by next Friday.
Thu (08 May): Chance of AM Drizzle. Slight Chance Showers. Snow Level 4000 Feet. 40/58
Fri (09 May): Becoming Partly Cloudy. 37/64
Sat (10 May): Increasing Clouds. Chance of Light Rain Late...Mainly North. 40/69
Sun (11 May): Chance of Showers and Cooler. Snow Level Dropping to 3-4000 Feet. 43/58
Mon (12 May): Mostly Cloudy. Chance of a Shower Early...Afternoon Clearing. 40/63
Tue (13 May): Chance of Light Rain North. Partly Cloudy South. 45/65
Wed (14 May): Becoming Mostly Sunny and Warmer. 46/72
Thu (15 May): Sunny and Very Warm. 49/80
weather at oda.state.or.us
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