[willamette-fcst] Forecast - Tuesday, July 17th, 2007
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Tue Jul 17 08:31:08 PDT 2007
Daily Smoke Management Forecast
Oregon Department of Agriculture
Smoke Management Program
Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts.
Tuesday, July 17th, 2007 at 9:00am.
Agricultural burning is not recommended.
Preparatory burning is not allowed.
Propane flaming is not allowed.
Stack burning is not allowed.
A strong uppper-level low pressure area, centered about 400
miles west of the Oregon Coast, is spreading clouds and
light rain across Western Oregon and Western Washington this
morning. The moist southerly flow aloft will continue to
circulate showers into the region today under cloudy skies.
The morning ODA surface analysis showed weak onshore
gradients across Washington and Oregon, with gradient
stacking east of Salem. This pattern is not conducive to
good ventilation, in the Willamette Valley, even with mixing
heights near 5000 feet this afternoon.
The upper-level low pressure area is forecasat to slowly
move to near the Southern Oregon Coast by late Wednesday,
which will continue the southerly flow aloft of moist and
increasingly unstable air over Oregon. Therefore, cool and
damp conditions will persist through Wednesday.
Var 3 this morning, WNW 5-10 this afternoon.
SW 3 this morning, SSW 7 this afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height today will be near 5000 feet. Ventilation index 35.
Salem\'s high temperature today will be near 74.
Minimum relative humidity will be near 51%.
Salem sunset tonight: 8:54pm; sunrise tomorrow: 5:43am.
An upper-level trough of low pressure is forecast, by
computer models, to be directly over Western Oregon Thursday
morning, which should continue the showers across the
region. It is expected to lift northeastward, into Eastern
Washington, Thursday afternoon, with showers tapering
off in the Willamette Valley.
Another upper-level low pressure area is forecast to set up
camp over the Eastern Pacific, beginning Friday, with an
unseasonably strong jet stream directing a series of weather
systems into Southern British Columbia. The first of these
weather fronts may extend far enough south to bring showers
to Western Oregon Friday afternoon. It appears that the jet
stream will move just far enough northward, over the
weekend, for drier and warmer weather to return to the
region, with southwesterly flow aloft and weak onshore flow
at the surface.
Tomorrow (18 Jul): Cloudy and Cool with Showers. Chance of a Thunderstorm. 59/74
Thu (19 Jul): Morning Showers. Becoming Partly Cloudy. 58/76
Fri (20 Jul): Increasing Clouds. Chance of Showers Late. 55/79
Sat (21 Jul): Partly Cloudy. 58/82
Sun (22 Jul): Mostly Sunny. 58/85
Mon (23 Jul): Mostly Sunny. 58/88
Tue (24 Jul): Mostly Sunny. 60/85
weather at oda.state.or.us
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