[willamette-fcst] Forecast - Wednesday, February 4th, 2009
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Wed Feb 4 08:59:32 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.
Issued:
Wednesday, February 4th, 2009 at 9:00am.
Burn Advisory:
Agricultural burning is not recommended.
Stack burning is not allowed.
Weather Discussion:
Willamette Valley temperatures climbed into the mid and
upper 50s Tuesday afternoon with Aurora hitting 60 degrees.
Offshore winds helped coastal temperatures soar to 70
degrees at Tillamook and Newport. It was also very mild in
the mountains Tuesday, with Timberline Lodge topping out at
55 degrees. The freezing level was at 11,000 feet Tuesday
afternoon. East of the Cascades, Redmond and Klamath Falls
both had highs Tuesday of 62 degrees. However, some valley
locations stayed in the mid and upper 40s.
Fair skies and light winds overnight allowed temperatures to
drop below freezing across much of the Willamette Valley by
early this morning, with minimums in the upper 20s common.
The exception was near the western end of the Comumbia
Gorge, where brisk easterly winds kept the low-level air
stirred up, and minimum temperatures stayed near 40 degrees.
Offshore pressure gradients were still in place this
morning across the state. Easterly winds were gusting at
high as 30-40 mph at times from Troutdale to Corbett. Winds
were light in the Willamette Valley, but easterly winds were
blowing around 10 mph along the coast at Newport.
A strong upper-level ridge of high pressure will continue
the dry and mild weather today across the region. The
freezing level was between 10,000 and 11,000 feet over
western Oregon. The Salem sounding showed a strong
low-level temperature inversion from the surface, where
temperatures were near freezing, up to 2500 feet, where
temperatures were in the upper 50s. That will make for very
poor ventilation conditions again today, with mixing heights
below 1000 feet.
Satellite imagery showed areas of fog in the southern
Willamette Valley and the valleys of southwestern Oregon.
Dry offshore flow kept fog from forming across most of the
north valley overnight. Middle and high clouds covered most
of the state, in response to an upper-level low pressure
system off the California coast. That will result in some
filtering of the sunshine this afternoon, which should cap
temperatures a few degrees cooler than on Tuesday. Valley
highs will be generally in the low to mid 50s with light
winds. Middle and high clouds should continue to increase
overnight, with areas of fog forming...mainly in the central
and south valley. Temperatures should not be quite as
chilly overnight with minimums close to the freezing mark.
Surface Winds:
Var 0-5 this morning, N 0-5 this afternoon.
Transport Winds:
N 4 this morning, N 4 this afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height today will be near 700 feet. Ventilation index 3.
High Temperature:
Salem\'s high temperature today will be near 54.
Humidities:
Minimum relative humidity will be near 52%.
Sunrise/Sunset:
Salem sunset tonight: 5:25pm; sunrise tomorrow: 7:26am.
Extended Outlook:
Major changes in the weather pattern are in store, beginning
Thursday, across the Pacific Northwest. A weather system,
dropping southeastward from the Gulf of Alaska, will combine
forces with the upper-level low pressure system, off the
California coast, and bring mostly cloudy skies with
increasing showers to western Oregon Thursday afternoon
through Friday. The freezing level should drop to near 6000
feet Thursday afternoon, and down to 4000 feet Friday, with
improving ventilation conditions. Overnight minimums will
be warmer, but daytime highs will progressively cool.
A transitory ridge will likely bring a dry and farily mild
day to the region Saturday with a stronger weather system
bringing rain and mountain snow on Sunday. Showers will
continue into Monday with very low snow levels. A warm
front may spread light rain back across northwestern Oregon
by Tuesday afternoon with a cold front bringing increasing
rain and mountain snow again Wednesday.
Tomorrow (05 Feb): Mostly Cloudy. Chance of PM Showers. 33/50
Fri (06 Feb): Mostly Cloudy. Scattered Showers. Snow Level 3000 Feet. 38/48
Sat (07 Feb): Partly Cloudy and Mild. Freezing Level 5-6000 Feet. 34/51
Sun (08 Feb): Rain with Mountain Snow. Snow Level Dropping to 2000 Feet. 34/46
Mon (09 Feb): Decreasing Showers. Show Level 1500 Feet. 35/46
Tue (10 Feb): Increasing Chance of Rain. Snow Level Rising to 3500 Feet. 33/46
Wed (11 Feb): Rain and Mountain Snow. Snow Level 3000 Feet. 36/46
ODA Meteorologist
weather at oda.state.or.us
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