[willamette-fcst] Forecast - Wednesday, June 10th, 2009
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Wed Jun 10 09:07:50 PDT 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.
...Next Update Not Scheduled Until Thursday, June 11th, at 9:00am...
Wednesday, June 10th, 2009 at 9:00am.
Agricultural burning is allowed. Suggested burn times are from 11:00am until 7:00pm.
Straw stack burning is allowed from 11:00am until 7:00pm.
Western North America is under a split-flow jet stream
pattern, with one branch of strong winds aloft being
directed over the top of a ridge of high pressure, in the
northern Gulf of Alaska, and then diving southeastward into
Montana. A weaker southern branch is undercutting the Gulf
of Alaska Ridge and sending weak upper-level troughs into
the the west coast of the United States.
An upper-level trough approached the central and southern
Oregon coastline Tuesday, triggering the development of
mumerous afternoon and evening showers and thunderstorms
across Oregon. The storms were slow-moving, due to farily
light winds aloft, and produced locally heavy rainfall.
Burns received over one-half inch of rain Tuesday evening
with up to three-quarters of an inch reported near Bend, in
Low-level onshore flow, into western Oregon, helped to keep
shower and thunderstorm development confined mainly from the
Cascades eastward Tuesday. However, some of the showers
continued through the night, with southeasterly flow aloft
bringing them northwestward over the northern Willamette
Valley this morning. Some sprinkles fell this morning as
far south as Salem with light rain reported in McMinnville,
Aurora, and Hillsboro.
Satellite imagery showed generally cloudy skies over all of
Oregon at mid-morning. Doppler radar showed a band of light
rain stretching from near Redmond, in central Oregon,
northwestward to over the northern Willamette Valley. The
areas of rain were decreasing in intensity, with the cool
morning air helping to stabilize the atmosphere. The ODA
surface analysis showed the thermal trough had shifted
eastward, into Idaho, with low-level onshore flow now
extending across most of Oregon. That will slightly
stabilize the air mass over Oregon today, with the strongest
afternoon shower and thundershower development shifting east
of the state.
Mid-morning temperatures were mostly in the mid to upper 50s
across western Oregon, under cloudy skies. Light rain was
still falling over parts of the extreme northern Willamette
Valley. Skies were partly to mostly cloudy over central and
eastern Oregon with temperatures ranging from the low 50s,
with light rain in Redmond, to the mid 60s in Hermiston and
With a weak upper-level trough maintaining southerly to
southeasterly flow aloft over Oregon today, daytime heating
will, once again, destabilize the air mass enough for some
showers to develop...mainly from the Cascades eastward.
There may also be a few thunderstorms. Southeasterly flow
aloft could swing some showers northwestward into the
Willamette Valley tonight, much like last night. Continued
onshore flow will keep skies mostly cloudy today west of the
Cascades with Willamette Valley high temperatures only
climbing to near or slightly below normal.
S 3-6 this morning, SW 5-10 this afternoon.
SW 5 this morning, W 10 this afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height today will be near 4000 feet. Ventilation index 40.
Salem\'s high temperature today will be near 70.
Minimum relative humidity will be near 55%.
Salem sunset tonight: 8:58pm; sunrise tomorrow: 5:25am.
Little change in the weather pattern is expected through
this week with a series of weak upper-level troughs
continuing to bring mostly cloudy skies to western Oregon
with a chance of showers and even a slight chance of
thundershowers. A weak ridge should bring some drying early
next week. Onshore flow will hold temperatures near or
slightly below normal across western Oregon through at least
Sunday with some warming early next week.
Tomorrow (11 Jun): Mostly Cloudy. Chance of Light Showers. 52/70
Fri (12 Jun): Mostly Cloudy. Chance of Showers. Slight Chance of T-Storms. 53/71
Sat (13 Jun): Mostly Cloudy. Chance of Showers. Slight Chance T-Storms. 52/70
Sun (14 Jun): Mostly Cloudy. Slight Chance of Showers. 52/71
Mon (15 Jun): Morning Clouds. Becoming Partly Sunny. 50/74
Tue (16 Jun): Morning Clouds. Becoming Mostly Sunny. 50/75
Wed (17 Jun): Mostly Sunny. 50/77
weather at oda.state.or.us
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