[willamette-fcst] Forecast - Monday, January 25th, 2010

[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, January 25th, 2010 at 9:00am.

Burn Advisory:
     Recommended burn times for agricultural burning are from now to 3:00pm.
     Stack burning is not allowed.

            ...The rules for stack burning have changed...

     In 2010, a total of 1000 acres can be stack-burned in the
     Willamette Valley.  Pre-registration is now required, and
     stack burning permits must be obtained from an ODA staff member

Weather Discussion:
     A fairly potent storm system dumped from one-half to one
     inch of rain across western Oregon Sunday.  Snow levels were
     just low enough for the precipitation to fall as snow over
     the Cascade passes, where up to a foot of new snow fell. 
     The rain and snow tapered off overnight.  Cloudy skies and
     occasional light rain held western Oregon temperatures
     mostly in the low to mid 40s overnight.

     Skies remained cloudy over the state this morning with a
     moist southwesterly flow aloft.  Doppler radar and surface
     reports showed bands of very light rain continuing to come
     onshore an rotate across western Oregon.  ODOT road cameras
     showed snow showers over the Cascade passes, with the
     freezing level over Salem measured this morning near 5000
     feet.  The ODA surface analysis showed  south-southeasterly
     pressure gradients across western Oregon with surface winds
     generally in the 5-10 mph range.

     Skies will stay mostly cloudy today across all of Oregon
     today, with continued moist southwesterly flow aloft.  A
     split-flow pattern in the jet stream will direct a weather
     system into mainly southern and southeastern Oregon later
     today and tonight, with most of the rain staying south and
     east of the Willamette Valley.  However, there will continue
     to be a chance for light rain, at times, across the valley. 
     Snow levels should stay low enough for a few more inches of
     snow over the Cascade passes today, especially south, where
     precipitation will be the heaviest.  South winds will likely
     warm afternoon temperatures into the lower 50s, across the
     Willamette Valley, and provide good ventilation.

Surface Winds:
     S 5-12 this morning, S 5-12 this afternoon.
Transport Winds:
     S 12 this morning, S 12 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 2000 feet.  Ventilation index 24.
High Temperature:
     Salem\'s high temperature today will be near 53.
Humidities:
     Minimum relative humidity will be near 66%.
Sunrise/Sunset:
     Salem sunset tonight: 5:10pm; sunrise tomorrow: 7:38am.

Extended Outlook:
     Rain showers will taper off, from west to east, across the
     state on Tuesday.  A transitory ridge of high pressure will
     bring dry weather Wednesday and most of Thursday, with the
     next weather system coming onshore Thursday night.  That
     looks to be yet another mild storm, with the snow level
     rising to at or above 6000 feet.  A weak cold front should
     push through the region by Friday, lowering the snow level
     back to near the Cascade passes.

Tomorrow (26 Jan):  Mostly Cloudy.  Slight Chance of Showers.  Snow Level 4000 Feet.  38/50

Wed (27 Jan):  Partly Sunny.  Snow Level Rising to 5-6000 Feet.  35/50

Thu (28 Jan):  Increasing Clouds and Mild.  Snow Level 6-7000 feet.  35/52

Fri (29 Jan):  Rain Turning to Showers.  Snow Level Dropping to 4500 Feet.  37/50

Sat (30 Jan):  Chance of Showers.  Snow Level 4000 Feet.  37/49

Sun (31 Jan):  Mostly Cloudy.  Snow Level 3500 Feet.  35/50

Mon (01 Feb):  Mostly Cloudy.  Chance of Showers.  Snow Level 4000 Feet.  36/50

ODA Meteorologist
weather at oda.state.or.us