[willamette-fcst] Forecast - Monday, April 7th, 2008

[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.

Issued: 
     Monday, April 7th, 2008 at 9:00am.

Burn Advisory:
     Agricultural burning is allowed.  Suggested burn times are from 8:00am until 6:00pm.
     Straw stack burning is allowed from 8:00am until 6:00pm.

Weather Discussion:
     It was a very cool and damp weekend across Washington and
     Oregon.  A strong cold front dumped between one-quarter and
     one-half inch of rain along the Washington and Oregon
     Coastal regions Saturday.  About a tenth of an inch of rain
     fell in the Willamette Valley with slightly greater amounts
     across the interior of Western Washington.  Ahead of the
     cold front, southerly winds gusted between 20 and 30 mph at
     times Saturday afternoon and evening.  Snow levels Saturday
     were at about 3000 feet over Oregon, with most high
     temperatures in the Willamette Valley only reaching the
     upper 40s (about 10 degrees below normal for this time of year).

     In the wake of the cold front, a cold upper-level trough
     brough instability showers and blustery onshore winds to
     most of Oregon Sunday.  Total rainfall amounts in the
     Willamette Valley were generally less than one-tenth of an
     inch Sunday with one-quarter to one-half inch of rain
     falling in showers along the Oregon Coast.  Snow levels were
     3-4000 feet Sunday with valley high temperatuers only
     climbing into the lower 50s.  The snow level continued to
     drop overnight and was near 1500 feet over Northern Oregon
     and 2000 feet over Southern Oregon this morning.

     Up to 8 inches of now snow fell at the ski resorts in the
     Oregon Cascades during the past 24 hours.  The Cascade
     Passes were snow-packed this morning with snow falling and
     temperatures in the mid 20s.  Cold instability showers will
     continue over Oregon today with strong onshore flow focusing
     the shower activity over the coast range and the Cascades. 
     The National Weather Service is continuing a snow advisory
     for the Cascades until 3 pm this afternoon for 4-7
     additional inches of snow.  A few rain and snow showers will
     also pop up over Central and Eastern Oregon today.

     Showers were continuing this morning across Western Oregon
     but will decrease this afternoon, as the upper-level trough
     pushes eastward to over Idaho.  Clouds held overnight
     temperatures in the 35-40 degree range.  A few sunbreaks are
     likely this afternoon, but high temperatuers will ony climb
     to near 50 degrees due to good mixing and very cold air
     aloft.  Southerly surface winds this morning will become more
     westerly, in the wake of the upper-level trough, this afternoon.

Surface Winds:
     S 10-15 G20 this morning, Becoming W 10-15 G20 this afternoon.
Transport Winds:
     SSW 20 this morning, WSW 15-20 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 4800 feet.  Ventilation index 96.
High Temperature:
     Salem\'s high temperature today will be near 50.
Humidities:
     Minimum relative humidity will be near 65%.
Sunrise/Sunset:
     Salem sunset tonight: 7:48pm; sunrise tomorrow: 6:39am.

Extended Outlook:
     Clouds from the next weather system were already within
     350 miles of the coastline this morning and will move onshore
     this evening.  That should keep valley temperatures above
     freezing overnight, in spite of the very cold air mass over the
     state.  More rain is likely across Western Oregon by early
     Tuesday morning with showers continuing through Tuesday night.

     We may get a brief break from the rain early Wednesday,
     before a weak system brings back a good chance of light rain
     Wednesday evening.  A building ridge of high pressure
     appears as if it will begin a drying and warming process
     Thursday that could last until early next week.

Tomorrow (08 Apr):  Rain Likely...Turning to Showers.  Snow Level 2000 Feet.  38/50

Wed (09 Apr):  Mostly Cloudy.  Good Chance of Light Rain Late.  35/42

Thu (10 Apr):  Mostly Cloudy.  Slight Chance of Rain Early.  37/58

Fri (11 Apr):  Mostly Sunny and Warmer.  37/64

Sat (12 Apr):  Partly Cloudy and Mild.  40/66

Sun (13 Apr):  Mostly Cloudy.  Chance of Rain.  42/63

Mon (14 Apr):  Chance of Rain and Cooler.  40/56

ODA Meteorologist
weather at oda.state.or.us