[willamette-fcst] Forecast - Monday, September 22nd, 2008
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Mon Sep 22 08:14:57 PDT 2008
Daily Smoke Management Forecast
Oregon Department of Agriculture
Smoke Management Program
Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts.
...Corrected Stack Burning Areas...
Monday, September 22nd, 2008 at 9:00am.
Agricultural burning is allowed. Suggested burn times are from 1:00pm until 6:30pm.
Preparatory burning is not allowed.
Propane flaming is not allowed.
Straw stack burning is allowed, for dry stacks, from Albany northward from 1:00pm until 6:30pm.
Straw stack burning is not allowed south of Albany.
Summer finished on a damp note with most of the Willamette
Valley picking up between one-tenth and one-quarter inch of
rain overnight. Autumn officially began this mornig at
8:44am. Morning satellite imagery showed cloudy skies over
the Willamtte Valley with what appeared to be the southern
end of a dissipating cold front moving across NW Oregon.
Doppler radar showed areas of light rain over the eastern
valley with a few showers rolling onshore in the wake of the
weak cold front. The ODA surface analysis showed high
pressure building into the Central Oregon Coast with weak
onshore pressure gradients across the Willamette Valley.
A cool upper-level trough will swing over NW Oregon this
morning with a few more showers likely...mainly in the
north. It will slide east of the region this afternoon with
the flow aloft drying out and becoming northwesterly.
Showers will taper off this afternoon with a few sunbreaks.
Temperatures will be below normal with highs in the mid 60s.
Fields will need time to dry before they can be burned.
Cool air aloft will help mixing heights climb to near 5000
feet this afternoon. Transport winds will likely stay
northwesterly, in the north valley, which will allow for the
burning of dry stacks, from Albany northward. Transport
winds are forecast to become northerly this afternoon south
of Albany. The cool air mass will continue to dry overnight
with partial clearing allowing valley temperatures to drop
into the low 40s by Tuesday morning.
Light this morning, NW 5-12 Albany North...N 8-15 South of Albany this afternoon.
NW 6 this morning, NW 10 Albany north...N 10 South of Albany this afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height today will be near 5000 feet. Ventilation index 50.
Salem\'s high temperature today will be near 65.
Relative humidity drops to 50% by 4pm.
Minimum relative humidity will be near 45%.
Salem sunset tonight: 7:08pm; sunrise tomorrow: 7:01am.
A transitory ridge of high pressure is forecast to bring
some sunshine early Tuesday with middle and high clouds
increasing late, from the the next weather system, in a
westerly flow aloft. The lastest computer model guidance is
suggesting that transport winds may become favorable for
burning by late Tuesday but more likely Wednesday. The
models are generally holding off the rain until late
Wednesday, which would allow for burning Wednesday
afternoon. Damp fields may require fluffing to take
advantage of this potential burning opportunity.
An upper-level trough will keep a chance of showers in the
forecast through Thursday evening...with most of the rain in
the north valley. Another one-tenth to one-quarter of an
inch of rain is possible from late Wednesday through
Thursday...especially on the east side of the north valley.
Showers should taper off by Thursday evening. A weak
upper-level trough is forecast to approach the coastline
Friday, which may create another burning opportunity Friday
The long-range models are coming into agreement on building
a ridge of high pressure over the Pacific Northwest this
weekend. The low-level winds are forecast to become
northerly by Saturday afternoon and perhaps offshore by
Sunday, which would bring increasing amounts of sunshine and
near to above normal temperatures. That pattern would
effectively dry any remaining damp fields in preparation for
a burn opportunity around Wednesday of next week.
Tomorrow (23 Sep): Partly Cloudy. Increasing High Clouds in the Afternoon. 41/71
Wed (24 Sep): Mostly Cloudy. Increasing Chance of Light Rain. 47/71
Thu (25 Sep): Chance of Showers...Decreasing Late. 50/68
Fri (26 Sep): Mostly Cloudy. Increasing Chance of Showers. 48/73
Sat (27 Sep): Becoming Mostly Sunny in the Afternoon. 48/73
Sun (28 Sep): Sunny and Warmer. 47/77
Mon (29 Sep): Sunny and Warm. 47/79
weather at oda.state.or.us
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