[willamette-fcst] Forecast - Friday, July 11th, 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: 
     Friday, July 11th, 2008 at 9:00am.

Burn Advisory:
     Agricultural burning is not recommended.
     Preparatory burning is not allowed.
     Propane flaming is not allowed.
     Stack burning is not allowed.

Weather Discussion:
     Upper level ridge continues to dominate the area weather. 
     This keeps the air mass fairly stable but allows daytime
     temperatures to rise above normal throughout the Willamette
     Valley. The thermal trough edged northward from California
     to the southern Oregon coast.  Doesn\'t appear that the
     trough will hold its position and is forecast to slip
     inland, into the western valleys by mid day.  Result is that
     slightly offshore low-level flow this morning gives way to
     northerly winds through the afternoon.

     The morning surface analysis shows a direct north to south
     pressure gradient, and northerly wind flow will thus be
     fairly brisk during the afternoon.  Air quality looks fairly
     good this morning but the winds will tend to concentrate any
     generated pollutants in the south end of the valley.

Surface Winds:
     N 7-12 this morning, N 13-18 this afternoon.
Transport Winds:
     NNE 12-18 this morning, N 15-20 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 4300 feet.  Ventilation index 65.
High Temperature:
     Salem\'s high temperature today will be near 90.
Humidities:
     Relative humidity drops to 50% by 9.
     Minimum relative humidity will be near 19%.
Sunrise/Sunset:
     Salem sunset tonight: 8:58pm; sunrise tomorrow: 5:38am.

Extended Outlook:
     Upper ridge remains locked over the Pacific Northwest
     through the weekend.  By early next week, a minor
     disturbance pushes through the ridge.  This will increase
     the onshore flow somewhat and may tend to turn the low-level
     wind flow slightly more northwesterly.  Disturbance looks
     weak enough that precipitation in the interior looks
     unlikely.  The coast and Coast Range may see a little
     precipitation but in the Willamette Valley the impact will
     be predominately increased morning clouds.  

     Temperatures will cool as the marine air flow into the
     Willamette Valley increases.  Daytime temperatures are still
     likely to be slightly above normal.


Tomorrow (12 Jul):  Sunny.  49/90

Sun (13 Jul):  Partly Cloudy.  52/88

Mon (14 Jul):  Partly Cloudy.  53/82

Tue (15 Jul):  Partly Cloudy.  52/80

Wed (16 Jul):  Partly Cloudy.  51/82

Thu (17 Jul):  Partly Cloudy.  52/81

Fri (18 Jul):  Mostly Sunny.  53/83


ODF Meteorologist for
ODA Meteorologist
weather at oda.state.or.us