[willamette-fcst] Forecast - Monday, July 14th, 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, July 14th, 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:
     An upper level ridge of high pressure will shift slowly
     eastward today.  Surface pressure charts show the thermal
     trough from the central valley of California, extending
     northward into the Rogue Valley then weakly into the south
     end of the Willamette Valley. Pressure gradients as of 8am
     included:  Newport to Salem, 0.1 mb onshore; Salem to
     Redmond, 1.0 mb offshore; and Eugene to Medford, 2.4 mb
     northerly.  Obviously the Medford Draw is dominating.  

     Surface reports show low level flow is generally northerly
     and computer models indicate this trend continuing.   Warm
     air aloft will limit mixing heights and it looks like the
     maximum will struggle to reach about 3000 feet this
     afternoon.


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 3000 feet.  Ventilation index 45.
High Temperature:
     Salem\'s high temperature today will be near 89.
Humidities:
     Relative humidity drops to 50% by 9.
     Minimum relative humidity will be near 25%.
Sunrise/Sunset:
     Salem sunset tonight: 8:56pm; sunrise tomorrow: 5:41am.

Extended Outlook:
     The axis of the upper level ridge will be well to the east
     of the area tomorrow and a trough of low pressure aloft will
     be movinging into the Pacific Northwest.  As the trough
     nears, more cool marine air will move into the interior
     valleys west of the Cascades.  The trasition to a more
     onshore flow could give a burn opportunity tomorrow or
     possibly Wednesday, depending on timing.  After midweek the
     ridge of high pressure should slowly rebuild with warmer
     temperatures returning.


Tomorrow (15 Jul):  Sunny.  53/84

Wed (16 Jul):  Partly Cloudy.  51/80

Thu (17 Jul):  Partly Cloudy.  49/82

Fri (18 Jul):  Sunny.  51/83

Sat (19 Jul):  Sunny.  52/83

Sun (20 Jul):  Sunny.  53/82




ODA Meteorologist
weather at oda.state.or.us