[willamette-fcst] Forecast - Monday, November 16th, 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, November 16th, 2009 at 9:00am.

Burn Advisory:
     Agricultural burning is allowed.  Suggested burn times are from now until 2:30pm.
     Straw stack burning is allowed from now until 2:30pm.

Weather Discussion:
     Most of the rain stayed north of the region over the weekend
     with generally less than one-tenth of an inch falling in the
     Willamette Valley.  After a mostly dry Saturday, a warm
     front brought some very light rain at times to the
     Willamette Valley on Sunday, with high temperatures
     recovering to near-normal.  The north coast received between
     one-third and three-quarters of an inch of rain, but only
     sprinkles fell on the central and south coast, and across
     the southwestern interior.

     Oregon is in the warm-sector of an impressive storm system
     this morning.  Satellite imagery showed the leading edge of
     a broad band of clouds extending from southern British
     Columbia, across Washington and western Oregon this morning.
     The solid cloud-shield extended several hundred miles
     offshore.  Doppler radar showed rain across all of western
     Washington and extending south into extreme northwestern
     Oregon.  Some sprinkles were also making it over the
     Cascades, into east-central Washington.

     A strengthening surface low-pressure area was headed for the
     northern tip of Vancouver Island, British
     Columbia...generating strong southerly pressure-gradients,
     ahead of the cold front, across western Washington and
     western Oregon.  Southerly winds were gusting to between 50
     and 65 mph from the southern Washington Coast to the central
     Oregon Coast and 25-35 mph across the interior of western
     Washington and northwestern Oregon...including the
     Willamette Valley.  Those southerly winds were ushering mild
     air across the region, with the freezing levels over Salem
     and Medford were measured at 7800 and 11,100 feet
     respectively this morning.  Western Oregon temperatures were
     in the low to mid 50s this morning.

     The offshore cold front will not make much eastward progrees
     today, as waves of low-pressure form along it and make their
     way towards Vancouver Island.  That will maintain the mild
     but brisk southerly winds today and tonight across western
     Washington and western Oregon.  The National Weather Service
     has issued a high wind warning, through tonight, for the
     Oregon Coast, where southerly winds will continue to gust
     over 60 mph and may locally top out as high as 90 mph
     tonight across exposed headlands on the north coast.  The
     Willamette Valley will have a blustery but mild day, with the
     bulk of the rain holding off until tonight, as the cold
     front finally makes it closer to the coastline.

Surface Winds:
     S 15-25 G35 this morning, S 15-25 G35 this afternoon.
Transport Winds:
     S 40 this morning, S 40 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 2000 feet.  Ventilation index 80.
High Temperature:
     Salem\'s high temperature today will be near 57.
Humidities:
     Minimum relative humidity will be near 40%.
Sunrise/Sunset:
     Salem sunset tonight: 4:42pm; sunrise tomorrow: 7:13am.

Extended Outlook:
     The strong cold front is forecast to slowly sweep across
     western Oregon Tuesday morning, with significant rain and
     blustery conditions expected in the Willamette Valley.  The
     steady rain will likely turn showery Tuesday afternoon, with
     southerly winds turning more southwesterly and decreasing. 
     The snow level will start out near 6000 feet, Tuesday
     morning, and rapidly drop to near 2500 feet, in the wake of
     the cold front, by Tuesday night.

     Showers will continue through most of Wednesday, with
     another weather system forecast to increase the rain and
     wind across western Oregon Thursday.  Snow levels will climb
     back to near or above the Cascade passes by Thursday
     afternoon, as the cold front nears the coastline.  Rain will
     turn to showers Friday, with the cold front likely pushing
     east of the Cascades by evening.  The snow level will drop
     back to around 2500 feet by Friday night.

     Showers will continue Saturday, with yet another weather
     system forecast to come onshore Saturday night.  Showers
     will taper off Sunday with a possible dry day Monday, as a
     ridge of high pressure begins building over the region.

Tue (17 Nov):  Rain and Blustery South Winds.  Snow Level Dropping to 2500 Feet Late.  47/51

Wed (18 Nov):  Showers.  Snow Level 2500-3000 Feet.  38/49

Thu (19 Nov):  Increasing Rain and Blustery.  Snow Level Rising to 4-5000 Feet.  42/51

Fri (20 Nov):  Rain Turning to Showers.  Snow Level Dropping to 2500 Feet.  41/49

Sat (21 Nov):  Showers.  Snow Level 2500-3000 Feet.  39/48

Sun (22 Nov):  Rain Turning to Showers.  Snow Level near 3000 Feet.  42/49

Mon (23 Nov):  Partly Sunny.  40/51

ODA Meteorologist
weather at oda.state.or.us