[willamette-fcst] Forecast - Monday, February 9th, 2009
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Mon Feb 9 09:01:30 PST 2009
Daily Smoke Management Forecast
Oregon Department of Agriculture
Smoke Management Program
Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts.
Monday, February 9th, 2009 at 9:00am.
Agricultural burning is allowed. Suggested burn times are from now until 3:30pm.
Straw stack burning is allowed from now until 3:30pm.
A Pacific cold front dropped between one and two-tenths of
an inch of rain along the coast Sunday with lighter amounts
inland. Snow levels dropped to about 2000 feet Sunday
afternoon, with about 1-3 inches of new snow falling in the
Cascades. Cloudy skies held Willamette Valley highs in the
mid to upper 40s Sunday, after a mostly sunny Saturday with
highs in the low to mid 50s.
The cold front pushed east of the Cascades Sunday night with
clearing skies and a cool air mass allowing temperatures to
drop below freezing across most of western
Oregon...including along the coast. Hillsboro was one of
the colder spots, in the Willamette Valley, droping at least
down to 26 degrees. McMinnville and Eugene both dipped to
28. Along the coast, Astoria fell to 30 degrees and
tempertures fell to the freezing mark as far south as North
Bend and Brookings. Meanwhile, cloudy skies and areas of
very light snow kept central and eastern Oregon temperatures
mostly in the 20s overnight, with a few areas dropping in
Satellite and Radar showed an impressive line of showers,
associated with an upper-level trough, just moving onto the
coastline at mid-morning. The air mass with these showers is
quite cold, and Astoria was even reporting light snow with
temperatures in the low 30s. The upper-level trough, and
associated showers, will move across western Oregon later
this morning through early this afternoon. The snow level
will be between 500 and 1000 feet, but wet snow could mix to
the valley floor at times. High temperatures will only
climb into the low to mid 40s. A transitory ridge of high
pressure will bring some partial clearing overnight with
temperatures, once again, dropping to near or below the
freezing mark across most of western Oregon.
The Salem sounding this morning showed significant cooling
from near the surface to 30,000 feet, with southerly
low-level winds becoming northwesterly above about 2000
feet. The freezing level was measured at just 2100 feet.
Ventilation conditions across western Oregon should be good
today, as the upper-level trough moves onshore. Low-level
winds are southerly this morning but are forecast to turn
more westerly, in the wake of the upper-level trough, later
S 5-10 this morning, WSW 5-12 this afternoon.
S 10 this morning, W 12 this afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height today will be near 3000 feet. Ventilation index 36.
Salem\'s high temperature today will be near 43.
Minimum relative humidity will be near 62%.
Salem sunset tonight: 5:32pm; sunrise tomorrow: 7:20am.
Another cold Pacific storm is forecast to spread clouds and
precipitation back onshore Tuesday morning. The air mass
will initially be quite cold, so the precipitation will
begain as snow down to very low elevations...perhaps even on
the valley floors. The low-pressure center is forecast drop
southward, off the Oregon Coast, late Tuesday. That will
keep the low-level winds offshore and maintain very low snow
levels across all of western Oregon...especially near the
The National Weather Service has issues a Winter Storm
Watch, for possible significant snow Tuesday, in the coastal
range, the Columbia Gorge, the Cascade foothills (above 1000
feet), and for the Cascades. Wet snow could fall on the
valley floors, but significant accumulations are not
expected at the very lowerest elevations. This system will
need to be watched closely for the potetial to produce
sticking snow even at sea level, especially in the extreme
northern Willamette Valley, due to the persistent offshore
flow, from the Columbia Gorge, keeping the low-level air
The rain and snow should taper off late Tuesday, as the
low-pressure center moves inland into northern California.
A few showers or flurries are still possible into
Wednesday...especially in the south valley. Wednesday
morning temperatures will be near freezing with afternoon
highs warming a few degrees from Tuesday. The next system
is forecast to take more of a southerly track, mainly into
northern California, with some light rain and snow possibly
spreading as far north as about Portland Thursday night and
Friday. Some drying is expected Saturday, under a cold
northerly flow aloft.
Tomorrow (10 Feb): Rain/Snow Mix. Significant Snow Above 1000 Feet. 31/42
Wed (11 Feb): Decreasing areas of light Rain/Snow. Partial PM Clearing. 32/46
Thu (12 Feb): Increasing Clouds. Chance of Rain/Snow Mix. 32/45
Fri (13 Feb): Mostly Cloudy. Chance of Rain/Snow Mix. 32/45
Sat (14 Feb): Gradual Clearing and Cool. 30/47
Sun (15 Feb): Mostly Sunny and Cool. 28/48
Mon (16 Feb): Mostly Sunny and Cool. 28/48
weather at oda.state.or.us
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