[willamette-fcst] Forecast - Thursday, November 5th, 2009

[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.

NOON UPDATE

Issued: 
     Wednesday, November 4th, 2009 at 12:00pm.

Burn Advisory:
     Agricultural burning is allowed.  Suggested burn times are from now until 3:00pm.
     Straw stack burning is allowed from now until 3:00pm.

Weather Discussion:
     Visible satellite imagery showed a few remaining pockets of
     fog in the southern Willamette Valley late this morning,
     otherwise just high clouds were streaming over the region in
     a southwesterly flow aloft.  After locally starting out near
     the freezing mark this morning, Willamette Valley
     temperatures ranged from the mid 40s, where fog was
     persisting in the south valley, to the mid 50s across most
     of the north valley.

     The late morning ODA surface analysis continued to show
     easterly pressure gradients across western Oregon, with
     easterly winds blowing through the coast range passes to the
     beaches.  East winds were continuing to gust over 30 mph at
     the western end of the Gorge, with light and variable winds
     across most of the Willamette Valley.

     The few remaining areas of morning valley fog will give way
     to high and mid-level clouds, in the afternoon, with
     increasing southwesterly flow aloft over Washington and
     Oregon. Valley highs will range from the mid 50s south,
     where the morning fog was more persistent, to the low 60s in
     the north.  Ventilation conditions will slowly improve this
     afternoon, as southeasterly transport winds beging to
     increase.

Surface Winds:
     ESE 3 this afternoon.
Transport Winds:
     SSE 6 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 1700 feet.  Ventilation index 10.
High Temperature:
     Salem\'s high temperature today will be near 63.
Humidities:
     Minimum relative humidity will be near 40%.
Sunrise/Sunset:
     Salem sunset tonight: 4:56pm; sunrise tomorrow: 6:56am.

Extended Outlook:
     The upper-level ridge is forecast to continue shifting
     eastward on Thursday, with the first of several potent
     weather systems forecast to come onshore by the afternoon. 
     The first cold front is forecast to push across western
     Oregon Friday morning.  Precipitation will turn showery
     Friday afternoon, with the snow level dropping to around to
     Cascade passes.

     A colder system is forecast to come onshore Saturday, with
     locally heavy rain and mountain snows...followed by slow
     drying on Sunday.  A warmer system is forecast to come
     onshore late Monday, with snow levels likely lifting above
     the Cascade passes.  A cool upper-level trough will drop the
     snow level back below the passes Tuesday and Wednesday.

Thu (05 Nov):  Increasing Clouds.  Rain Developing in the Afternoon.  South Winds.  40/60

Fri (06 Nov):  Rain Turning to Showers.  Snow Level Dropping to 4-5000 feet.  48/54

Sat (07 Nov):  Rain.  Possibly Heavy Mountain Snow.  Snow Level 3-4000 Feet.  44/51

Sun (08 Nov):  Decreasing Showers.  Snow Level 4000 Feet.  42/54

Mon (09 Nov):  Rain Developing Late.  Snow Level Risning to 5-6000 Feet.  40/56

Tue (10 Nov):  Showers.  Snow Level 3-4000 Feet.  40/54

Wed (11 Nov):  Showers.  Snow Level 3000 Feet.  40/53

ODA Meteorologist
weather at oda.state.or.us