[willamette-fcst] Forecast - Tuesday, February 24th, 2009

Willamette Valley Ag/Burning Forecast willamette-fcst at listsmart.osl.state.or.us
Tue Feb 24 09:02:59 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: 
     Tuesday, February 24th, 2009 at 9:00am.

Burn Advisory:
     Agricultural burning is allowed.  Suggested burn times are from now until 4:00pm.
     Straw stack burning is allowed from now until 4:00pm.

Weather Discussion:
     A Pacific cold front moved across western Oregon Monday
     afternoon and was followed by a secondary cold front
     overnight.  The combination of storms dropped from about
     one-half to one-and-a-quarter inches of rain across mot of
     western Oregon.  It was a little drier over extreme
     southwestern Oregon, but heavier rain fell there over the
     weekend.  The bottom line is that all of western Oregon
     fianlly got a good soaking rain, after a quite dry January
     and first half of February.

     In addition, a fairly intense low-pressure area moved to
     near the northern Washington coast early this
     morning...producing fairly strong southerly winds from the
     central Washington Coast south along the Oregon Coast. 
     Hoquiam, Washington had a peak gust early this morning of 46
     mph with gusts to near 50 mph along the extreme northern
     Oregon Coast, at Clapsop Spit. Garibaldi had a peak gust of
     47 mph, and capre Mears (1421 feet near Tillamook) had a
     gust of 64 mph.  Blustery winds and bursts of heavy rain
     swept across the Willamette Valley overnight.  The Salem
     Airport had a peak gust of 46 mph.

     The mid-morning ODA surface analysis showed southerly
     pressure gradients beginning to relax a bit across western
     Washington and Oregon, with a weakening low-pressure center
     just off the northern Washington Coast.  South winds were
     still gusting to 35 mph along the northern Oregon Coast, at
     Astoria, and to near 20 mph in the Willamette Valley.  The
     rainy and windy conditions kept overnight temperatures above
     40 degrees along the coast and across the Willamette Valley.
     Mid-morning readings were in the mid to upper 40s.

     Satellite imagery showed generally cloudy skies across
     Washington and most of western Oregon.  There were some
     breaks in the clouds across central and eastern Oregon. 
     Doppler radar continued to show a few showers moving across
     northwestern Oregon, in a strong southewesterly flow aloft. 
     The air aloft cooler overnight with the snow level dropping
     to about 3500 feet early this morning.  Snow was falling
     over the Cascade passes this morning with 4 inches of new
     snow at Government Camp, on Mt. Hood.  The higher elevations
     on Mt. Hood picked up heavy snow overnight, with Timberline
     Lodge getting 15 inches of new snow.

     The flow aloft is forecast to turn more westerly this
     afternoon, which should enhance snow shower activity over
     the Cascades.  Snow advisories are in effect there for up to
     12 inches of new snow above 3500 feet by Wednesday morning. 
     The coast and western valleys will continue to see scattered
     rain showers today and tonight with slowly decreasing winds.
     Valley highs will be in the low to mid 50s.  Lows tonight
     should, once again, remain above 40 degrees.

Surface Winds:
     S 10-20 G30 this morning, SW 10-20 G25 this afternoon.
Transport Winds:
     SW 30 this morning, SW 25 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 4000 feet.  Ventilation index 120.
High Temperature:
     Salem\'s high temperature today will be near 53.
Humidities:
     Minimum relative humidity will be near 69%.
Sunrise/Sunset:
     Salem sunset tonight: 5:53pm; sunrise tomorrow: 6:56am.

Extended Outlook:
     A cold upper-level low-pressure system is forecast to drop
     southward, from southern British Columbia, to just off the
     Washington Coast Wednesday.  That will increase the
     precipitation and winds across the region with snow levels
     lowering to near 3000 feet by Wednesday night.  Another foot
     of snow could fall in the Cascades late Wednesday into
     Thursday, as snow levels drop to 1000 feet or lower.  The
     coastal range passes may also see sticking snow Thursday, as
     the very cold upper-level low-pressure system swings
     onshore.  Some wet snow is also possible in the higher hills
     around the Willamette Valley on Thursday.

     The upper-level low-pressure system is forecast to move east
     of the Cascades Thursday night with showers tapering off and
     skies clearing.  That will allow for much colder overnight
     temperatures.  Valley minimums will likely drop to near or
     below freezing.  A transitory ridge of high pressure may
     bring a mostly dry day Friday, with a touch of sunshine.

     The next weather system is forecast to develop further
     offshore, with increasing southwesterly flow aloft briefly
     lifting snow levels to near or above the Cascade passes
     Saturday afternoon.  That system is forecast to move onshore
     with rain and blustery winds Saturday night and Sunday, with
     snow returning to the mountains.  Showers will continue
     Monday and Tuesday with low snow levels.

Tomorrow (25 Feb):  Showers Increasing in the Afternoon.  Snow Level 3500 Feet.  42/52

Thu (26 Feb):  Showers.  Snow Level 1000 Feet or Lower.  37/47

Fri (27 Feb):  Partly Sunny and Cool.  Slight Chance of a Shower.  31/52

Sat (28 Feb):  Increasing Clouds.  Chance of PM Rain.  Snow Level 5000 Feet.  38/53

Sun (01 Mar):  Rain.  Snow Level Dropping to 3000 Feet.  40/52

Mon (02 Mar):  Showers.  Snow Level  Near 3000 Feet.  39/50

Tue (03 Mar):  Showers.  Snow Level near 2000 Feet.  37/50

ODA Meteorologist
weather at oda.state.or.us



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