[willamette-fcst] Forecast - Friday, November 6th, 2009

Fri Nov 6 09:00:31 PST 2009

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: 
     Friday, November 6th, 2009 at 9:00am.

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

Weather Discussion:
     a strong cold front moved onshore Thursday afternoon and
     across western Oregon Thursday evening.  It brought quite
     strong southerly winds to the Oregon Coast and blustery
     conditions to the Willamette Valley.  Southerly winds
     between 40 and 50 mph were common along the entire coastal
     strip with some much stronger gusts.  Garibaldi, on the
     north coast, recorded a gust to 91 mph shortly after 5 p.m.
     Thursday, with a gust of 89 mph recorded at the Sea Lion
     Caves, on the central coast, around 6 p.m.  Southerly wind
     gusts to 80 mph were reported at Tillamook Head and
     Waldport.  Cape foulweather recored a 78 mph gust.  Blustery
     south winds moved into the Willamette Valley Thursday
     evening, with gusts around 30 mph common.

     Rainfall amounts were also impressive, with most of the
     coastline getting just over an inch of rain.  Some of the
     Cascade foothills also picked up over an inch, with most of
     the Willamette Valley getting between one-third and
     two-thirds of an inch.  A cool upper-level trough followed
     the cold front onshore overnight, with numerous showers and
     even a few thunderstorms...mainly along the coast.

     The cold front was pusing into Idaho at mid-morning.  Colder
     air aloft had dropped the freezing levels over Salem and
     Medford to 5200 feet and 5900 feet by 5 a.m. this morning. 
     ODOT road comeras showed the rain had changed to snow over
     the Cascades passes, with pass temperatures near 30 degrees.
      Showers will continue today, along with blustery southwest
     winds.  There is a slight chance of a thunderstorm.  Heavy
     snow is expected over the Cascade passes.  Valley highs will
     only climb into the low to mid 50s.

Surface Winds:
     SW 10-20 G25 this morning, SW 7-17 G20 this afternoon.
Transport Winds:
     SW 22 this morning, S 20 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 2000 feet.  Ventilation index 44.
High Temperature:
     Salem\'s high temperature today will be near 54.
Humidities:
     Minimum relative humidity will be near 69%.
Sunrise/Sunset:
     Salem sunset tonight: 4:53pm; sunrise tomorrow: 6:59am.

Extended Outlook:
     Another cold front is forecast to come onshore Saturday
     afternoon and evening.  Snow levels will likely remain in
     the 3-4000 foot range, with an additional foot of snow
     possible over the Cascade passes.  BLustery and wet weather
     will continue along the coast and in the Willamette Valley. 
     Showers will taper off Sunday, as a weak and transitory
     upper-level ridge moves across the region.  with snow levels
     lifting to around 5000 feet.

     The next weather system is forecast to come onshore around
     midday Monday.  Ahead of it, snow levels will lift to around
     6000 feet.  The cold front should bring another round of
     soaking rains to western Oregon Monday night.  A cool
     upper-level trough will bring showery conditions Tuesday. 
     The snow level is forecast to drop below 4000 feet, with
     accumulating snow likely over the mountain passes.  The
     upper-level trough is forecast to weaken, and push east of
     the region, by late Wednesday, with a drier northwesterly
     flow aloft developing.

     The long-range models are showing show an upper-level ridge
     building into the coastline just strongly enough to keep
     Thursday and Friday dry, with areas of morning valley fog. 
     Another wet weather system is forecast to come onshore next
     weekend.

Sat (07 Nov):  Increasing Rain.  Heavy Mountain Snow Likely.  Snow Level 3-4000 Feet.  44/52

Sun (08 Nov):  Mostly Cloudy.  Decreasing Chance of Showers.  Snow Level 4000 Feet.  40/55

Mon (09 Nov):  Increasing Clouds. Rain be Evening.  Snow Level Rising to 6000 Feet.  39/55

Tue (10 Nov):  Showers with Mountain Snow.  Snow Level 3-4000 Feet.  45/52

Wed (11 Nov):  Decreasing Showers.  Snow Level 3000 Feet.  41/52

Thu (12 Nov):  Areas of AM Fog.  Partly Sunny.  38/54

Fri (13 Nov):  Areas of AM Fog.  Partly Sunny.  39/52

ODA Meteorologist
weather at oda.state.or.us