[willamette-fcst] Forecast - Thursday, February 11th, 2010
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Thu Feb 11 12:08:57 PST 2010
Daily Smoke Management Forecast
Oregon Department of Agriculture
Smoke Management Program
Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts.
Thursday, February 11th, 2010 at 12:00pm.
Recommended burn times for agricultural burning are from now to 3:30pm.
Straw stack burning is allowed from now until 3:30pm.
...The rules for stack burning have changed. Stack burning permits must
be obtained from ODA Smoke Management Personnel...
Increasing southerly winds sent Willamette Valley temperatures climbing into the upper 40s
by midnight, last night, and into the low 50s early this morning. Satellite imagery showed
a one large band of clouds covering most of Oregon...extending westward into another,
developing, cloud-shield a couple hundred miles offshore. Only spotty areas of light rain
and high elevation snow were falling across the state at midday. ODOT road cameras showed
wet pavement over the Cascade passes, with the snow level around 6000 feet.
The developing offshore system has a fair amount of moisture associated with it, but the
split-flow jet stream pattern will act to shear it apart, as it approaches the coastline
this evening. A surface low pressure center was developing about 300 miles off of the
southern Oregon coast late this morning, with a warm front advancing out ahead of it
towards Washington and Oregon. Moderate southeasterly pressure gradients were producing
south wind gusts around 30 mph on the southern Oregon Coast and 20 mph on the central
coast late this morning. Southeasterly winds were in the 5-15 mph range across the
The low pressure center is forecast to track close enough to the coastline later today
to bring strong southerly winds to much of the Oregon Coast. The National Weather Service
has issued high wind warnings, along the Oregon Coast, for possible southerly winds
gusting to around 70 mph, from later this afternoon until about midnight. Southerly winds
will also increase later this afternoon in the Willamette Valley, with gusts of 35-40 mph
possible by this evening. Rain will also be on the increase today, with snow levels likely
staying above the passes. Mild southerly winds will lift temperatures into the mid 50s.
SSE increasing to 12-25 G35 late this afternoon. Gusts to 40 mph possible this evening.
S 35 this afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height today will be near 2500 feet. Ventilation index 88.
Salem\'s high temperature today will be near 56.
Minimum relative humidity will be near 69%.
Salem sunset tonight: 5:35pm; sunrise tomorrow: 7:17am.
When the offshore cold front moves inland late tonight, snow levels will drop to near
the Cascade passes. 3-6 inches of snow are possible, at pass level, before the
precipitation tapers off Friday morning. The brisk southerly winds across western
Oregon will rapidly taper off overnight, with the steady rain turning to showers.
A colder weather system is forecast to spread more rain onshore around midday Friday.
The snow level will likely stay near or slightly below the Cascade passes. Southeasterly
winds will not be as brisk with this system but should provide good ventilation conditions.
A transitory ridge of high pressure should dry things out Saturday, especially south, as a
warm front brushes by to our north. Afternoon temperatures could become quite mild
Saturday with some sunbreaks possible. A weak cold front will likely bring some light rain
Sunday, with snow levels likely remaining above the Cascade passes. Another warm front
may bring some sprinkles to northern sections Monday, with skies staying mostly cloudy
Tuesday. An upper level ridge is forecast to bring spring-like conditions next Wednesday
Fri (12 Feb): Increasing Rain in the Afternoon. Snow Level Dropping to 4000 Feet. 46/54
Sat (13 Feb): Chance of Light North. Mostly Cloudy South. Snow Level 6000 Feet. 44/58
Sun (14 Feb): Mostly Cloudy and Mild. Chance of Light Rain. Snow Level 5500 Feet. 41/53
Mon (15 Feb): Chance of Light Rain...Mainly North. Snow Level 6000 Feet. 39/54
Tue (16 Feb): Mostly Cloudy. Snow Level 5000 Feet. 37/54
Wed (17 Feb): Areas of AM Fog. Becoming Partly Sunny & Mild in the Afternoon. 36/57
Thu (18 Feb): Mostly Sunny and Spring-Like. 38/62
weather at oda.state.or.us
More information about the willamette-fcst