[willamette-fcst] Forecast - Monday, September 14th, 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.

Issued: 
     Monday, September 14th, 2009 at 9:00am.

Burn Advisory:
     Agricultural burning is not recommended.
     Preparatory burning is not allowed.
     Propane flaming is allowed from 12:00pm until 5:00pm.
     Stack burning is not allowed.

Weather Discussion:
     Southerly flow aloft brought lots of clouds and some light
     showers to western Oregon overnight. Some sections of the
     Willamette Valley picked up a couple of hundredths of an
     inch of rain in the pre-dawn hours this morning. An
     upper-level trough will swing across northern
     California...into Nevada today. The southerly flow aloft
     will slowly become more southwesterly and begin to dry out.

     Visible satellite imagery showed considerable clouds over
     the northern and central WIllamette Valley at mid-morning
     with mostly clear skies along much of the coast and over
     southwestern Oregon.  Skies should gradually clear this
     afternoon over the Willamette Valley. Cool air aloft will
     keep high temperatures from climbing above the mid 70s, with
     the warmest readings likely in the sotuh valley. Daytime
     heating should lift mixing heights to around 4000 feet by
     late this afternoon.  Southerly transport winds this morning
     are forecast to become southwesterly by late this afternoon,
     which may allow for limited open burning. 

Surface Winds:
     SE 5-10 this morning, SSW 5-10 this afternoon.
Transport Winds:
     S 8 this morning, SW 10 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 4000 feet.  Ventilation index 40.
High Temperature:
     Salem\'s high temperature today will be near 74.
Humidities:
     Minimum relative humidity will be near 51%.
Sunrise/Sunset:
     Salem sunset tonight: 7:24pm; sunrise tomorrow: 6:51am.

Extended Outlook:
     A transitory upper-level ridge is forecast to move over the
     region Tuesday and then east of the region with increasing
     southerly flow aloft Wednesday.  A cold front is forecast to
     move onshore Wednesday night...possibly bringing some light
     showers as far south and east as the Willamette Valley.  A
     weak westerly flow aloft is forecast for Thursday, which
     should allow for some clearing in the afternoon.

     Another weak cold front is forecast to push mainly north of
     the region Friday night and Saturday.  It does not appear as
     if this system will be strong enough to bring any
     precipitation as far south as the Willamette Valley, but it
     bring enough onshore flow to produce some clouds with
     seasonal temperatures.  A stronger upper-level ridge is
     forecast to warm temperatures well above normal by early
     next week.

Tomorrow (15 Sep):  Mostly Sunny & Warmer.  54/85

Wed (16 Sep):  Increasing Clouds in the Afternoon.  Chance of Showers Late.  55/78

Thu (17 Sep):  Mostly Cloudy AM...Afternoon Clearing.  54/77

Fri (18 Sep):  Mostly Sunny.  52/80

Sat (19 Sep):  Partly Cloudy.  54/77

Sun (20 Sep):  Sunny and Warmer.  54/85

Mon (21 Sep):  Sunny and Very Warm.  55/90

ODA Meteorologist
weather at oda.state.or.us