[willamette-fcst] Forecast - Tuesday, February 2nd, 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.

Issued: 
     Tuesday, February 2nd, 2010 at 9:00am.

Burn Advisory:
     Recommended burn times for agricultural burning are from 12:00pm to 3:00pm.
     Stack burning is not allowed.

Weather Discussion:
     El Nino conditions in the tropical Pacific Ocean led to an
     unusually mild January across northwestern Oregon.  January,
     2010 was one of the top 5 warmest on record for Astoria,
     Portland, Salem, and Eugene, with the monthly average
     temperature about 5 degrees above normal.  Rainfall for the
     month was above normal along the coast...tapering off to
     near-normal in the Willamette Valley.

     February is also off to a mild start, and will likely remain
     that way.  El Nino usually brings mild Februarys to the
     Pacific Northwest with below normal precipitation and
     mountain snowfall.

     In the short-term...a transitory ridge of high pressure
     stabilized the atmosphere overnight across western Oregon,
     leading the areas of dense fog formation in the Willamette
     Valley by early this morning.  Visibilities remained less
     than one-quarter of a mile across much of the valley at
     mid-morning. Temperatures were in the low to mid 40s with
     light winds.

     Satellite imagery showed a rather compact weather system
     centered about 400 miles off the southern Oregon Coast this
     morning.  The associated cloud-shield was inching slowly
     eastward towards the coastline at mid-morning.  Some clouds
     and light showers were also spreading northward into extreme
     southwestern Oregon.

     Clouds will slowly increase, over the top of the fog deck,
     from southwest to northeast, across western Oregon today. 
     Surface winds will remain very light offshore, with
     transport winds becoming more southerly by this afternoon. 
     Rain will likely spread across much of southwestern Oregon
     this afternoon and across the remainder of western Oregon
     tonight and Wednesday.  The snow level will remain in the
     4-5000 foot range, with a few inches of snow likely over the
     Cascade passes tonight through Wednesday.

Surface Winds:
     NNE 0-5 this morning, NNE 3-7 this afternoon.
Transport Winds:
     SE 5 this morning, S 5 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 1500 feet.  Ventilation index 8.
High Temperature:
     Salem\'s high temperature today will be near 51.
Humidities:
     Minimum relative humidity will be near 71%.
Sunrise/Sunset:
     Salem sunset tonight: 5:22pm; sunrise tomorrow: 7:29am.

Extended Outlook:
     Wednesday looks wet across all of western Oregon, with
     steady rain tapering off to showers by late in the day. 
     Temperatures will remain mild, with valley highs near 50
     degrees.  Several inches of snow are likely in the Cascades,
     with the snow level just below the passes.  A weak ridge
     will likely bring some brief drying Wednesday night, before
     another weather system brings more rain and higher elevation
     snow onshore Thursday.

     Showers will continue into Friday, with an El Nino jet
     stream pattern once again directing the bulk of the next
     weather system, on Saturday, into California.  It appears as
     if we may slowly dry out by early next week, with continued
     mild temperatures.

Tomorrow (03 Feb):  Rain Turning to Showers.  Snow Level 3500 Feet.  40/49

Thu (04 Feb):  Rain Developing and Mild.  Snow Level Rising to 4500 Feet.  38/50

Fri (05 Feb):  Mostly Cloudy.  Chance of Showers.  Snow Level 4000 Feet.  39/55

Sat (06 Feb):  Rain Developing...Mainly South.  Snow Level 4000 Feet.  38/51

Sun (07 Feb):  Decreasing Chance of Showers.  Snow Level 4000 Feet.  37/51

Mon (08 Feb):  Mostly Cloudy.  Slight Chance of Showers.  Snow Level 4000 Feet.  37/52

Tue (09 Feb):  Partly Sunny.  36/54

ODA Meteorologist
weather at oda.state.or.us