[willamette-fcst] Forecast - Wednesday, April 2nd, 2008

Wed Apr 2 10:09:01 PST 2008

Daily Smoke Management Forecast

Oregon Department of Agriculture
Smoke Management Program
Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts.

NOON UPDATE

Issued: 
     Wednesday, April 2, 2008 at 12:00 pm.

Burn Advisory:
     Agricultural burning is allowed.  Suggested burn times are from now until 5:30 pm.
     Stack burning is not allowed.

Weather Discussion:
     An unseasonably cold northerly flow aloft continues over the
     Pacific Northwest today.  A weak upper-level disturbance
     brought some clouds to NE Oregon early this morning, before
     pushing southeastward to over Idaho.  The remainder of
     Oregon was under mostly clear skies this morning.

     The dry and cold air mass lead to near record cold
     temperatures once again this morning.  Astoria set a new
     record low of 29 degrees (old record 30 set in 1980). 
     Eugene tied their record low of 27 degrees (previously set
     in 1980).  For the second day in-a-row, Salem missed a
     record low by 1 degree with a low of 27 (Salem\'s low
     temperature Tuesday was 28).  Hillsboro and McMinnville both
     dropped to 28 degrees...just missing their record lows. 

     A multitude of record lows were broken yesterday morning
     across Eastern Washington and Eastern Oregon, and I expect
     that more records were broken this morning. Redmond tied
     their April monthly record low Tuesday morning with 10
     degrees.  Meacham, in NE Oregon, significantly undercut
     their daily record low of 11 degrees, set in 1999, with a
     low Tuesday of 5.  The Dalles also set a new daily record
     low Tuesday morning with 25 degrees (the old record was 28
     degrees back in 1982).  It was slightly warmer in Meacham
     this morning with a low of 15 degrees.  Redmond and Rome
     fell to 14, Baker City and Burns fell to 17, and Klamath
     Falls dropped to 18.  The Dalles tied their record low this
     morning with 25 degrees (previously set in 1948), and
     Pendleton set a new record daily low temperature record with
     19 degrees (previously 20 in 1999).

     The sounding over Salem this morning showed some warming and
     drying aloft, so skies should stay sunny all day over
     Western Oregon.  The late-morning ODA surface analysis
     showed northerly gradients across the state with valley
     locations generally reporting north winds around 10 mph. 
     Northerly transport winds are not conducive to good valley
     ventilation, so stack burning is not allowed again today.

     Midday temperatures had warmed into the mid 40s across the
     valley and should warm into the upper 50s this afternoon
     under sunny skies.  Mostly sunny skies will also prevail
     over Central and Eastern Oregon this afternoon with highs
     generally in the 50s.

Surface Winds:
     N 10-15 G20 south valley this afternoon.
Transport Winds:
     NNE 15 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 4000 feet.  Ventilation index 60.
High Temperature:
     Salem\'s high temperature today will be near 59.
Humidities:
     Minimum relative humidity will be near 33%.
Sunrise/Sunset:
     Salem sunset tonight: 7:42pm; sunrise tomorrow: 6:48am.

Extended Outlook:
     Thursday should be the warmest day of the week from the
     Willamette Valley eastward across the state, as the
     upper-level ridge pushes over Washington and Oregon. 
     Northerly surface flow will turn onshore late in the day, as
     a weak thermal trough moves inland and then east of the
     Cascades.  The dry air mass and fair skies will allow
     morning minimums to dip near or below the freezing mark
     across the Willamette Valley Thursday morning with afternoon
     highs warming into the low to mid 60s.

     Clouds will increase Thursday night, as a weather system
     pushes through the upper-level ridge and approaches the west
     coast.  That should keep minimum temperatures above freezing
     Friday morning.  Afternoon temperatures in the valley will
     be about 10 degrees cooler than on Thursday with highs in
     the low to mid 50s.  Rain will likely move onshore by late
     Friday morning and spread across the state in the afternoon.
     The snow level should drop to about 4000 feet by Friday
     evening with accumulating snow possible over the Cascade
     Passes and in the mountains of NE Oregon.

     A weak transitory ridge is forecast to bring some drying and
     warming early Saturday with another weather system moving
     onshore late in the day.  The long-range models are coming
     into agreement on a fairly strong trough near the west coast
     for early next week. That means more rain, mountain snow,
     and below normal temperatures for Oregon...but we are used
     to that by now.

Tomorrow (03 Apr):  Mostly Sunny.  29/63

Fri (04 Apr):  Showers Likely.  Snow Level Dropping to 4000 Feet.  35/54

Sat (05 Apr):  Mostly Cloudy.  Rain Likely Late.  Snow Level 4000 Feet.  35/54

Sun (06 Apr):  Rain Turning to Showers.  Snow Level 4000 Feet.  38/53

Mon (07 Apr):  Rain Likely.  Snow Level Dropping to 2500 Feet.  38/53

Tue (08 Apr):  Showers Likely.  Chance T-Storms with Hail. Snow Level 2000 Feet.  37/52

Wed (09 Apr):  Mostly Cloudy.  Chance of Showers.  Snow Level 3-4000 Feet.  34/57

ODA Meteorologist
weather at oda.state.or.us