[willamette-fcst] Forecast - Friday, January 9th, 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.

...Next Update 9 a.m. Wednesday, January 14th, 2009...

NOON UPDATE

Issued: 
     Friday, January 9th, 2009 at 12:00pm.

Burn Advisory:
     Agricultural burning is not recommended.
     Stack burning is not allowed.

Weather Discussion:
     Many rivers in western Washington are still flooding today,
     due to recent heavy rain and melting snow.  Most rivers in
     northwest Oregon have crested and are now below flood stage.
     However, flood warmings remain in effect for the Nehalem
     River, which was still above flood stage late this morning.
     It crested at 10 am today and is forecast to slowly fall to
     flood stage by around 7 pm tonight.  Some minor flooding will
     continue in Clatsop and Tillamook Counties.  Flood warnings
     have been dropped for the Luckiamute River, near Suver, which
     was slightly below flood stage late this morning.

     The latest flood warnings can be accessed at:
     http://www.wrh.noaa.gov/pqr/

     The latest river levels and forecasts are at:
     http://ahps2.wrh.noaa.gov/ahps2/index.php?wfo=pqr

     The strong Pacific storm that brought heavy rain and strong
     winds to western Washington and northwestern Oregon, Tuesday
     and Wednesday, pushed east of the region yesterday with
     showers tapering off overnight.  Lowering snow levels and
     drier conditions have helped ease the flooding across the
     region.  Significant flooding is still occuring near
     Chehalis, Washington, where northbound Interstate 5 remained
     closed due to high water.

     The latest Oregon road conditions are at:
     http://167.131.0.179/Pages/RCmap.asp?curRegion=0&mainNav=RoadConditions

     Cooler air aloft dropped the freezing level to just 2700
     feet over Salem this morning.  Partial clearing overnight
     helped Willamette Valley temperatures drop to near 30
     degrees with areas of fog forming...mainly in the central
     and south valley. Eugene fell to an icy 29 degrees this
     morning with fog reducing visibilities at times to less than
     one-quarter of a mile.

     The late-morning ODA surface analysis showed high pressure
     over western Oregon with weak pressure gradients and very
     light winds.  Warming aloft today will trap cool and moist
     air near the surface, so fog and low clouds will have a
     tough time breaking up in portions of the Willamette Valley.
     McMinnville and Hillsboro still had fog at midday with
     temperatures in the mid 30s.

     Some sunshine had warmed temperatures into the low 40s in Portland
     and Salem.  Low clouds were holding the temperature in Eugene in
     the middle 30s. Afternoon highs today will range from near 40, in
     cloudy/foggy areas, to the mid 40s where the sun is able to break
     out.  Ventilation conditions will be poor, due to increasing 
     low-level temperature inversions and light transport winds.

Surface Winds:
     Var 0-5 this afternoon.
Transport Winds:
     SE 4 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 1000 feet.  Ventilation index 4.
High Temperature:
     Salem\'s high temperature today will be near 45.
Humidities:
     Minimum relative humidity will be near 68%.
Sunrise/Sunset:
     Salem sunset tonight: 4:50pm; sunrise tomorrow: 7:49am.

Extended Outlook:
     Westerly flow aloft will allow another Pacific storm to
     slide into western Washington Saturday.  Some light rain
     could make it south into northwestern Oregon late by in the
     day...continuing into Sunday.  An upper-level ridge is
     forecast to amplify, just off the coastline, Sunday with the
     flow aloft becoming northwesterly and drying out by Sunday night.

     The ridge is forecast to move over the region next week with
     dry weather and freezing levels rising to more than 10,000
     feet.  Ventilation conditions will continue to be stagnant.
     Easterly outflow will increase, from the Columbia Gorge, by
     Wednesday, which will help to clear skies in the north
     valley.  However, south valley locations may have fairly
     persistent fog much of next week.

Sat (10 Jan):  Areas AM Fog.  Mostly Cloudy.  Increasing Chance of Light Rain North.  30/45

Sun (11 Jan):  Mostly Cloudy.  Chance of Sprinkles North.  34/48

Mon (12 Jan):  Areas of AM Fog.  Partly Sunny.  35/50

Tue (13 Jan):  Areas of Fog...Mainly South.  Partly Sunny.  34/51

Wed (14 Jan):  Areas of Fog...Mainly South.  Mostly Sunny North.  34/51

Thu (15 Jan):  Areas of Fog...Mainly South.  Mostly Sunny North.  34/51

Fri (16 Jan):  Areas of Fog...Mainly South.  Mostly Sunny North.  34/51

ODA Meteorologist
weather at oda.state.or.us