[willamette-fcst] Forecast - Thursday, January 8th, 2009
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Thu Jan 8 12:01:10 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.
NOON UPDATE
Issued:
Thursday, January 8th, 2009 at 12:00pm.
Burn Advisory:
Agricultural burning is allowed. Suggested burn times are from now until 3:00pm.
Straw stack burning is allowed from now until 3:00pm.
Weather Discussion:
Many rivers in western Washington are flooding today, due to
recent heavy rain and melting snow. Some northwest Oregon
rivers also well above flood stage, especially the Wilson,
Trask and Nehalem rivers, near Tillamook. Most rivers have
crested and should drop to near or below flood stage by
Friday night. Numerous flood warnings are still in effect
across the region.
The latest flood warnings can be accessed at:
http://www.wrh.noaa.gov/pqr/
The latest river levels and forecasts are at:
http://ahps2.wrh.noaa.gov/ahps2/index.php?wfo=pqr
The strong Pacific storm that brought heavy rain and strong
winds to western Washington and northwestern Oregon, over
the past two days, finally pushed east of the region this
morning. The cold front was pushing into Idaho at midday.
Morning rains had tapered off across eastern Oregon, but it
was still windy with westerly gusts of 25-40 mph common.
Steady rain turned showery this morning west of the Cascades
with some sunbreaks.
Brisk southerly winds held temperatures up in the low 50s
across western Oregon overnight, with cooler
west-southwesterly winds ushering cooler air onshore this
morning. Most areas west of the Cascades recorded their
high temperatures for today shortly after midnight. Midday
temperatures were mostly in the upper 40s. Temperatures
will likely hold steady for the next few hours and then fall
off quickly this evening, as skies begni to clear.
The cold front had pushed east of Salem by the time the
morning sounding was taken. It showed considerable cooling
aloft, with the upper level winds shifting from
southwesterly to westerly. The freezing level over Salem
had dropped from 8000 feet Wednesday afternoon to only 4600
feet early this morning. Heavy rain had turned to snow over
the northern and central Cascade passes by mid-morning.
ODOT cameras showed packed snow at Government Camp and
Santiam Pass and new roadside snow along Willamette Pass.
Pass temperatures were near 30 degrees at midday with snow showers.
The lowering snow levels and decreasing rain will help to
ease the flooding west of the Cascades, which has been most
significant across western Washington, and to a lesser
degree in extreme northwestern Oregon. Near-record flooding
is occuring near Chehalis, Washington, where Interstate 5 is
closed due to high water. Hwy 101 is also closed from mile
post 64 to 65 near Tillamook due to high water.
The latest Oregon road conditions are at:
http://167.131.0.179/Pages/RCmap.asp?curRegion=0&mainNav=RoadConditions
Lees Camp, on highway 6 in the northern Oregonm coastal
range, has received 4.8 inches of rain in the past 24 hours
and 6.7 inches of rain in the past 48 hours. The Astoria
airport has received 4.01 inches of rain in the past 24
hours and nearly 5 inches in the past 48 hours. Rainfall
have also been very impressive across western Washington.
3-7+ inches of rain have falled in the past 48 hours from
Kelso (just over 3.5 inches), to Olympia (more than 6
inches), to Shelton (more than 7 inches). In contrast,
rainfall amounts taper off quickly, as you move south and
east into the Willamette Valley, where 48-hour rainfall has
been generally from one-half to one inch.
Cooler air aloft will drop the snow level to near 2500 feet
by this evening with the showers decreasing and becoming
mainly focused on the western slopes of the coast range and
Cascades. 3-6 inches of snow is possible over the Cascade
passes, with the greatest amounts in the north. Showers
will taper off tonight, as an upper-level ridge of high
pressure begins building over the region. Partial clearing
and colder air aloft will allow valley temperatures to fall
into the low to mid 30s by Friday morning with areas of fog.
Surface Winds:
W 10-20 this afternoon.
Transport Winds:
W 20 this afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height today will be near 2500 feet. Ventilation index 50.
High Temperature:
Salem\'s high temperature today will be near 51.
Humidities:
Minimum relative humidity will be near 75%.
Sunrise/Sunset:
Salem sunset tonight: 4:49pm; sunrise tomorrow: 7:49am.
Extended Outlook:
After areas of morning valley fog, some sunbreaks are likely
Friday. Westerly flow aloft will allow another Pacific storm
to slide into western Washington Saturday. Some rain could
make it south into northwestern Oregon late in the day. The
upper-level ridge is forecast to amplify Sunday with the
flow aloft becoming northwesterly and drying out.
The ridge is forecast to move over the region early next week
with dry weather expected and freezing levels rising to more
than 10,000 feet. Ventilation conditions will become stagnant.
Some easterly outflow from the Columbia Gorge will help to
clear skies in the north valley, but the south valley may
have fairly persistent fog much of next week.
Tomorrow (09 Jan): Areas of AM Fog. Becoming Partly Sunny. 34/46
Sat (10 Jan): Areas AM Fog. Mostly Cloudy. Increasing Chance of Light Rain North. 32/46
Sun (11 Jan): Mostly Cloudy. Chance of Sprinkles North. 34/48
Mon (12 Jan): Areas of AM Fog. Partly Sunny. 33/50
Tue (13 Jan): Areas of AM Fog...Mainly South. Partly Sunny. 34/51
Wed (14 Jan): Areas of AM Fog...Mainly South. Partly Sunny. 34/51
Thu (15 Jan): Areas of AM Fog...Mainly South. Partly Sunny. 34/51
ODA Meteorologist
weather at oda.state.or.us
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