[willamette-fcst] Forecast - Wednesday, April 7th, 2010

[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.

     This daily Willamette Valley Agricultural Weather Forecast will become a seasonal product,
     as of Friday April 16th. The last broadcast and email of this forecast will be Thursday,
     April 15th. It will return as the \"Willamette Valley Field Burning Weather Forecast,\"
     issued daily via email and broadcast on WPOZ 585, beginning Thursday July 1st.


Issued: 
     Wednesday, April 7th, 2010 at 9:00am.

Burn Advisory:
     Recommended burn times for agricultural burning are from now until 6:00pm.
     Straw stack burning is allowed from 11:00am until 5:00pm.

Weather Discussion:
     A building ridge of high pressure turned the flow aloft
     northwesterly overnight and stabilized the air mass enough
     to shut down the shower activity over western Oregon.  A
     warm front was spreading clouds across most of Washington
     and the northwestern corner of Oregon this morning.  Doppler
     radar and surface reports showed areas of light rain making
     it onto the Washington and northern Oregon coast...about as
     far south as Newport.  Some light rain was pushing over the
     northern coastal range, at mid-morning, and could make it
     into the western sections of the northern Willamette Valley.
     The warm front is forecast to lift north of the region by
     this afternoon.

     Satellite imagery showed clouds extending about as far south
     as North Bend, along the coast, and across Marion County in
     the Willamette Valley.  Skies were mostly sunny over the
     south valley at mid-morning.  Temperatures across western
     Oregon ranged from the upper 30s in the south, where skies
     were mostly clear, to the mid 40s in the north, under mostly
     cloudy skies. The ODA surface analysis showed very weak
     southeasterly pressure gradients across western Oregon with
     winds generally less than 10 mph.

     Skies should clear later today, from south to north across
     the Willamette Valley, as the offshore warm front lifts
     north of the region.  Freezing levels have jumped above 6000
     feet and will continue to rise through this afternoon. 
     Warmer air aloft and some sunshine will finally lift high
     temperatures to near normal this afternoon (low 60s). Some
     middle and high clouds will likely keep the north valley a
     few degrees cooler than the south valley.  

Surface Winds:
     SE 0-8 this morning, SSW 5-10 this afternoon.
Transport Winds:
     S 8 this morning, SSW 8 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 3000 feet.  Ventilation index 24.
High Temperature:
     Salem\'s high temperature today will be near 61.
Humidities:
     Minimum relative humidity will be near 51%.
Sunrise/Sunset:
     Salem sunset tonight: 7:48pm; sunrise tomorrow: 6:40am.

Extended Outlook:
     The break in the weather will be brief, with another strong
     cold front forecast to spread more rain onshore shortly
     after midnight.  Rain will likely spread into the Willamette
     Valley during the pre-dawn hours Thursday.  The cold front
     will also bring blustery south winds to both the coast and
     the Willamette Valley Thursday morning.  Snow levels will
     quickly drop in the wake of the cold front Thursday
     afternoon, with significant snow accumulations likely over
     the Cascade passes and in the higher elevations of the coast range.

     An upper-level trough will keep a chance of showers over the
     region Friday...mainly north.  We may get a brief break in
     the action, on Saturday, with the next weather system moving
     into the region Sunday.  Cool and showery conditions will
     likely persist through the first half of next week, with
     continued unseasonably low snow levels.

Tomorrow (08 Apr):  Rain, Windy, & Much Cooler.  Snow Level Dropping to 3000 Feet.  43/49

Fri (09 Apr):  Chance of Showers....Mainly North.  Snow Level 2-3000 Feet.  34/52

Sat (10 Apr):  Partly Cloudy.  Chance of Showers.  Snow Level Rising to 4-5000 Feet.  33/59

Sun (11 Apr):  Increasing Showers.  Cooler.  Snow Level 4000 Feet.  37/56

Mon (12 Apr):  Showers Likely.  Cooler.  Snow Level 3-4000 Feet.  36/53

Tue (13 Apr):  Showers Likely.  Continued Cool.  Snow Level 3000 Feet.  37/53

Wed (14 Apr):  Showers Likely.  Continued Cool.  Snow Level 3000 Feet.  37/53

ODA Meteorologist
weather at oda.state.or.us