[willamette-fcst] Forecast - Tuesday, January 22nd, 2008
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Tue Jan 22 11:59:43 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.
Tuesday, January 22nd, 2008 at 12:00pm.
Agricultural burning is allowed. Suggested burn times are from now until 3:00pm.
Straw stack burning is allowed from now until 3:00pm.
Under clear skies overnight, the dry air mass allowed
temperatures to rapidly cool to the lowest readings of the
winter across the Pacific Northwest. Most of Central and
Eastern Oregon was near or below zero this morning.
Meacham, in Northeast Oregon, dropped to 23 degrees below
zero for the cold spot in the state. Burns dipped to 14
below zero, Redmond bottomed out at 8 below and Pendleton
dropped to 3 above zero.
The cold air was continuing to be funneled through the
Columbia Gorge into the Willamette Valley this morning. The
Dalles, at the east end of the gorge, was just 11 degrees
this morning. At the west end of the gorge easterly winds
were gusting to near 40mph at troutdale late this morning
with temperatures still below freezing. Portland dropped to
23 this morning with calmer air in Hillsboro allowing the
temperatuture to fall to 19 degrees. Salem dipped to 23,
Corvallis and Eugene fell to 21. Below freezing
temperatures extended to the coastline this morning where
Astoria fell to 26 degrees and Newport hit 30 with east
winds gusting to near 30 mph.
Today will be a repeat of Monday with sunny skies, cool
temperatures, and strong offshore flow across the state.
Highs will climb to near 40 degrees across Western Oregon
with north to northeast winds. By late this morning
temperatures had recovered into the low to mid 30s in the
Willamette Valley and into the low 40s with easterly winds
along sections of the coast. The late-morning ODA surface
analysis showed strong high pressure centered over the
Columbia Basin of SE Washington and NE Oregon. A low
pressure center was just off the Central California
Coastline, with an associated low-pressure trough extending
northward to just off the Oregon Coast.
Mixing heights today should climb close to 2000 feet, with
enough of an offshore flow component to the transport winds
to allow for stack burning. The air mass over Oregon is
extremely dry with dew-point temperatures in the teens or
single digits west of the Cascades and single digits to
below zero across Central and Eastern Oregon. With the lack
of an insulating blanket of snow, frost sensitive crops will
continue to be in danger, from the cold temperatures, for at
least the next couple of mornings.
NNE 10-15 this afternoon.
NE 15 this afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height today will be near 1800 feet. Ventilation index 27.
Salem\'s high temperature today will be near 40.
Minimum relative humidity will be near 32%.
Salem sunset tonight: 5:06pm; sunrise tomorrow: 7:41am.
Temperatures will rapidly fall this evening under clear
skies and continued dry offshore flow. Wind-sheltered areas
of the Willamette Valley will likely drop into the upper
teens Wednesday morning. A decrease in the offshore flow,
slighly warmer air aloft, and a full day of sunshine should
help temperatures climb into the low 40s Wednesday afternoon.
Under clear skies, temperatures will rapidly fall back into
the 20s Wednesday night. A weather system is forecast to
drop southeastward from the Gulf of Alaska to just off the
Oregon Coast by Thursday afternoon. That will maintain the
surface offshore flow and keep low-level cold air in place
across Western Oregon, while increasing southwesterly flow
aloft feeds Pacific moisture over the cold dome.
This is a classic set-up for snow across Western Oregon for
Thursday afternoon. The limiting factor will be the amount
of moisture forecast to spread inland. At this time, it
appear that snowfall will be light with the greatest chance
for accumulating snow in the central and southern sections
of Western Oregon. The bulk of the moisture is expected to
stay offshore, as the system moves southward along the
Oregon Coast, then dives southeastward into Northern California.
Skies should begin to clear over the Willamette Valley
Thursday night with low-level cold air still in place across
all of Oregon. Friday appears to be a break-day from any
storm activity with mostly sunny skies and cool temperatures again.
The forecast gets very tricky after Friday with a stronger
system forecast by all the computer models to drop
southeastward from the Gulf of Alaska into the Pacific
Northwest. With low-level cold air still in place across
Western Oregon, the precipitation should at least begin as
snow near midday Saturday. How long it stays as snow will
depend on the exact track of the incoming system and is too
far out to call at this time. It appears that there will be
enough onshore flow, with the passage of the cold front
Saturday afternoon, to transition the snow to rain across
the lower elevations of Western Oregon, but the snow levels
will ramin low enough for heavy snow in the coast range and
A cold upper-level trough is forecast to move over the
region Sunday and Monday for showery conditions with very
low snow levels. Sticking snow above 500 feet, at times, is
a real possibility, with a threat of sticking snow again on
the valley floor. Another cold system may bring more rain
or snow to the region Tuesday.
Tomorrow (23 Jan): Sunny. 18/41
Thu (24 Jan): Increasing Clouds. Chance of Light Snow...Mainly South. 22/37
Fri (25 Jan): Mostly Sunny and Cool. 25/40
Sat (26 Jan): Snow...Likely Changing to Rain in the Afternoon. 28/42
Sun (27 Jan): Showers of Rain or Snow. Possible Significant Accumulations. 33/37
Mon (28 Jan): Showers of Rain or Snow. Possible Significant Accumulations. 32/37
Tue (29 Jan): Showers of Rain or Snow. Possible Significant Accumulations. 32/37
weather at oda.state.or.us
More information about the willamette-fcst