[willamette-fcst] Forecast - Thursday, October 1st, 2009

[Willamette Valley Ag/Burning Forecast]

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 Scheduled for Monday, October 5th, at 9:00am...

NOON UPDATE

Issued: 
     Thursday, October 1st, 2009 at 12:00pm.

Burn Advisory:
     Agricultural burning is allowed.  Suggested burn times are from now until 5:00pm.
     Propane flaming is allowed from now until 5:00pm.
     Straw stack burning is allowed from now until 5:00pm.

Weather Discussion:
     A weak warm front was pushing onto the Washington Coast late
     this morning. Satellite imagery showed cloudy skies covering
     most of western Washington and extreme northwestern Oregon. 
     Spotty light rain was falling mainly over northern sections
     of western Washington.  No rain was being reported over
     Oregon, although some possible sprinkles were showing up on
     Doppler radar near the north coast.  Astoria picked up .03
     inches of rain between 5am and 11am with .01 inches falling
     as far south and east as Scappoose.

     Mainly just middle and high clouds extended as far south and
     east as the Willamette Valley, with considerable filtered
     sunshine.  Skies were mostly sunny along the central and
     south coast as well as over southwestern Oregon.  Midday
     temperatures had warmed into the upper 50s and low 60s across
     western Oregon. Winds were from the SSE at less than 10 mph.

     The air mass is still cold, for early October.  The freezing
     level, early this morning, over Salem was just 6700 feet. 
     However, some warming aloft and filtered sunshine this
     afternoon should combine to lift Willamette Valley
     temperatures into the mid 60s.  That is still about 5
     degrees below average but a good half-dozen degrees warmer
     than Wednesday afternoon.

     A weak cold front is forecast to push across western
     Washington this evening and southeastward across the
     Willamette Valley overnight.  Clouds will be on the increase
     along the a chance of light rain.  Total rainfall amounts,
     from the cold front, are forecast to be very light...ranging
     from little or nothing to around one-tenth of an inch.

Surface Winds:
     SSE 5-10 mph...becoming SSW 5-10 late this afternoon.
Transport Winds:
     SW 10 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 3500 feet.  Ventilation index 35.
High Temperature:
     Salem\'s high temperature today will be near 66.
Humidities:
     Minimum relative humidity will be near 48%.
Sunrise/Sunset:
     Salem sunset tonight: 6:52pm; sunrise tomorrow: 7:12am.

Extended Outlook:
     In the wake of the weak cold front, forecast to move
     southeastward across the Willamette Valley early Friday,
     another quite strong and cool upper-level trough will drop
     into the Pacific Northwest.  Showers will likely increase
     across Washington and northern Oregon Friday, with scattered
     showers over all of Oregon Saturday. Snow levels will drop
     to as low as 3000 feet Saturday, with minor snow
     accumulations over the Cascade passes possible.

     The upper-level trough is forecast shift east of the
     Cascades Sunday, with the showers tapering off across
     western Oregon.  The trough will progress eastward, into
     Idaho, Monday, with a drier, but continued cool,
     north-northeasterly flow aloft developing.  An upper-level
     ridge is forecast to slowly build into the coastline next
     week, with dry and progressively warmer early-autumn weather.

Tomorrow (02 Oct):  Mostly Cloudy.  Increasing Chance of Showers From North to South.  47/63

Sat (03 Oct):  Showers Likely.  Slight Chance of T-Storms.  Snow Level 3-4000 Feet.  43/59

Sun (04 Oct):  Mostly Cloudy and Cool. Decreasing Chance of Showers.  41/63

Mon (05 Oct):  Patchy AM Fog or Low Clouds...Mostly Sunny in the Afternoon.  39/67

Tue (06 Oct):  Patchy AM Fog....Sunny and Warmer.  42/73

Wed (07 Oct):  Patchy AM Fog...Sunny and Warm.  43/75

Thu (08 Oct):  Patchy AM Fog...Sunny and Warm.  44/78

ODA Meteorologist
weather at oda.state.or.us