[willamette-fcst] Forecast - Tuesday, July 8th, 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: 
     Tuesday, July 8th, 2008 at 9:00am.

Burn Advisory:
_____________________________________________________________________

     ...Due to the Olympic Trials in Eugene, ODA will not be issuing
     any burning permits through July 8th....
_____________________________________________________________________

     Agricultural burning is not recommended.
     Preparatory burning is not allowed.
     Propane flaming is not allowed.
     Stack burning is not allowed.

Weather Discussion:
     A broad but flat upper-level ridge of high pressure is
     contining to build over the Pacific Northwest today.  Today
     will be another sunny and warm day across Oregon.  The early
     morning Salem sounding showed a few degrees of additional
     warming aloft, since Monday morning, with continued
     northeasterly transport winds.  Surface temperatures started
     warmer this morning than Monday morning with valley minimums
     in the 50s.  McMinnville was one of the cooler spots with a
     low of 50.  Eugene had a morning low of 54 degrees and Salem
     bottomed out at 55.

     The ODA surface analysis reflected the flat nature of the
     upper-level ridge.  Pressure gradients remainded onshore
     this morning into the Washington and the extreme Northern
     Oregon Coasts with some marine low clouds.  Northerly gradients
     prevailed across the remainder of the Oregon Coast and the
     interior of Western Oregon under sunny skies.  A thermal trough
     continued to build northward into SW Oregon.  Northerly winds
     should increase to between 10 and 20 mph across the Willamette
     Valley again this afternoon with gusts to near 30 mph in the
     south valley.  Temperatures will be at least 5 degrees warmer 
     today with highs near 90 degrees.

Surface Winds:
     N 5-15 G20 south valley this morning, N 10-20 G30 south valley this afternoon.
Transport Winds:
     NE 18 this morning, NNE 22 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 3500 feet.  Ventilation index 77.
High Temperature:
     Salem\'s high temperature today will be near 90.
Humidities:
     Relative humidity drops to 50% by 11am.
     Minimum relative humidity will be near 26%.
Sunrise/Sunset:
     Salem sunset tonight: 9:00pm; sunrise tomorrow: 5:35am.

Extended Outlook:
     The upper-level ridge will begin to flatten further, by late
     Wednesday, in response to an upper-level trough cutting
     across extreme Southern British Columbia.  That will likely
     increase the onshore flow across Western Oregon Wednesday
     night and Thursday with temperatures cooling to near normal.
     Transport winds may turn more northwesterly by Thursday
     afternoon, which would improve valley ventilation conditions
     for burning...especially north.

     A transitory ridge is forecast to turn the low-level flow
     northerly again Friday, with valley temperatures rebounding
     back into the mid 80s.  Another trough is forecast to
     increase the westerly flow aloft and turn the surface flow
     onshore again over the weekend.  A stronger trough is
     forecast to approach the coastline Monday with light showers
     possibly extending southward into Western Washington and NW
     Oregon by next Tuesday.

Tomorrow (09 Jul):  Sunny.  North Winds 10-20 mph.  55/91

Thu (10 Jul):  Mostly Sunny & Cooler.  Wind Becoming NW 10-20 in the Afternoon.  53/82

Fri (11 Jul):  Areas of Morning Clouds.  Mostly Sunny Afternoon.  50/85

Sat (12 Jul):  Mostly Sunny but Cooler.  50/80

Sun (13 Jul):  Morning Clouds.  Afternoon Clearing.  51/78

Mon (14 Jul):  Morning Clouds.  Partly Sunny.  53/78

Tue (15 Jul):  Mostly Cloudy.  Slight Chance of a Light Shower North.  53/75

ODA Meteorologist
weather at oda.state.or.us