[willamette-fcst] Forecast - Thursday, March 11th, 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: 
     Thursday, March 11th, 2010 at 9:00am.

Burn Advisory:
     Recommended burn times for agricultural burning are from now until 4:00pm.
     Straw stack burning is allowed from now until 4:00pm.

Weather Discussion:
     In case you haven\'t noticed, the weather has taken a turn
     for the worse.  After two months of mostly benign weather,
     stormy conditions have returned to the Pacific Northwest. 
     Satellite imagery showed clouds from an impressive frontal
     system covering all of Washington and Oregon this morning. 
     Doppler radar showed precipitation stretching from the coast
     to the Cascades, with not much spill-over into central and
     eastern Oregon yet.  The snow level has risen to about 4000
     feet this morning, with ODOT road cameras showing the snow
     staring again over the Cascade passes.

     This storm is also bringing blustery conditions to western
     Oregon this morning.  The ODA surface analysis showed
     southerly gradients continuing to increase, with the frontal
     system stalling just offshore.  Southerly winds were gusting
     between 40 and 50 mph along the northern and central coast. 
     Clapsop Spit recorded a gust to 51 mph, and Cape Mears had a
     gust of 49 mph.  In the coatal range, Mt. Hebo had a gust to
     63 mph.  Strong south winds have also made their way into
     the Willamette Valley this morning.  Salem has seen gusts to
     37 mph.

     The frontal system is forecast to stall near the coastline
     today, so rainy and blustery conditions will persist
     throughout the day along the coast and in the Willamette
     Valley.  Some light rain could also push into the interior
     of southwestern Oregon.  Rainfall totals have been generally
     about one-tenth of an inch or less, so far this morning. 
     However, significant rain is likely today from the coast
     range westward and in sections of the northern Willamette
     Valley.  Cloudy skies and rain will hold valley highs near
     50 degrees, even though the freezing level will be slightly
     above 5000 feet. 

Surface Winds:
     S 15-25 G35 this morning, S 12-22 G32 this afternoon.
Transport Winds:
     S 30 this morning, SSW 25 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 2500 feet.  Ventilation index 75.
High Temperature:
     Salem\'s high temperature today will be near 51.
Humidities:
     Minimum relative humidity will be near 61%.
Sunrise/Sunset:
     Salem sunset tonight: 6:13pm; sunrise tomorrow: 6:30am.

Extended Outlook:
     A low-pressure area is forecast to form a wave along the
     frontal zone tonight, keeping it stalled near the coastline.
     Southerly winds could become quite strong along the coast
     tonight, where the National Weather Service has issued a
     High Wind Watch for possible gusts to around 60 mph.  The
     cold front is forecast to finally move inland, across
     western Oregon, around midday Friday.  That will increase
     the rain and wind across the Willamette Valley.

     A cold upper-level trough, with much lower snow levels, is
     forecast to swing over the region Friday afternoon through
     early Saturday.  A weak upper-level ridge may be just strong
     enough to deflect a warm front north of the region on 
     Sunday.  Oregon should be under the influence of a mild
     southwesterly flow aloft on Monday, with the next weather
     system forecast to bring more rain onshore Tuesday afternoon.
     More stormy and cool weather is forecast for later next week.

Fri (12 Mar):  Rain and Windy...Turning Showery. Snow Level Dropping Below 2500 Feet.  45/52

Sat (13 Mar):  Decreasing Showers.  Snow Level 1000 Feet Early...Rising to 2500 Feet.  36/54

Sun (14 Mar):  Cool Start...Becoming Partly Sunny and Warmer.  33/59

Mon (15 Mar):  Increasing High Clouds and Mild.  37/63

Tue (16 Mar):  Rain Likely Developing.  Snow Level Above 5000 Feet..Dropping Late.  42/57

Wed (17 Mar):  Decreasing Chance of Showers.  Snow Level 3-4000 Feet.  38/55

Thu (18 Mar):  Chance of Rain and Mountain Snow.  Snow Level 3000 Feet.  37/53

ODA Meteorologist
weather at oda.state.or.us