[willamette-fcst] Forecast - Friday, March 12th, 2010
Willamette Valley Ag/Burning Forecast
willamette-fcst at listsmart.osl.state.or.us
Fri Mar 12 12:14:34 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.
Friday, March 12th, 2010 at 12:00pm.
Recommended burn times for agricultural burning are from now until 4:00pm.
Stack burning is not allowed.
A strong cold front stalled just off the Oregon coast overnight,
with an active warm front moving northward, down the Willamette
Valley, early this morning. Rainfall totals, from this storm, have
exceeded 1.5 inches along the coast, with Astoria setting a daily record
with 1.41 inches of rain on Thursday. About one-half of an inch of rain
fell across the Willamette Valley Thursday evening, with another quarter
of an inch falling this morning.
Strong south winds pounded the coastline overnight, with gusts of 75 mph
at Cape Mears and 72 mph at Cape Foul Weather. Garibaldi recorded a gust
of 71 mph. Cannon Beach had gusts to 60 mph. In the north coastal range,
Mt. Hebo recorded a gust of 82 mph at about 4:30 a.m. In the Willamette
Valley, southerly winds gusted to 39 mph at Salem and to 38 mph at
McMinnville early this morning.
The warm front moved through the north valley earlier this morning, with
temperatures climbing into the low 50s across much of the valley. Doppler
radar showed the steady rainfall had shifted east of the north valley by
mid-morning. However, a wave forming along the cold front, just off the
southern Oregon coast, was delaying the eastward progress of the southern
flank of the storm. Rain was continuing to fall late this morning from the
southern Willamette Valley southward across most of southwestern Oregon.
The late-morning ODA surface analysis showed that southerly pressure-gradients
had strengthened considerably across central and eastern Oregon, where wind
gusts between 35 and 45 mph were common. Meanwhile, the southerly gradients
were slowly relaxing west of the Cascades, but it was still a bit blustery in
some locations. Salem was still getting gusts to about 25 mph, with gusts over
30 mph along the coastline. Late-morning temperatures ranged from the low 40s,
with rain, in Eugene, to the low 50s, with some sunbreaks, in Astoria.
The snow level was near 5000 feet earlier this morning, but ODOT road cameras
showed the rain had changed to snow over the Cascade Passes by midday, with snow
beginning to accumulate on road surfaces. There will be a break in the steady
precipitation, from north to south, across western Oreogn this afternoon. The
north valley has already seen the rainfall let up. A cold upper-level trough will
bring showers to western Oregon later this afternoon and evening, with
snow levels continuing to drop. Expect wintry driving conditions over the
Cascade passes from now through early Saturday.
SW 10-20 G25 this afternoon.
SW 22 this afternoon.
Atmospheric Ventilation Conditions:
Maximum mixing height today will be near 3500 feet. Ventilation index 88.
Salem\'s high temperature today was 53. The afternoon high will be near 49.
Minimum relative humidity will be near 67%.
Salem sunset tonight: 6:14pm; sunrise tomorrow: 6:28am.
A cold upper-level trough, with much lower snow levels, is
forecast to swing over the region tonight and Saturday. A
weak upper-level ridge will move onshore Saturday evening
and clear skies across western Oregon. That will lead to
cool overnight temperatures Saturday night. However, a warm
front may bring enough middle and high clouds into the region
to hold minimums above the freezing mark. The upper-level
ridge may be just strong enough to deflect precipitation
from the warm front north of Oregon, but there is a chance of
light rain across the northwest corner of the state Sunday.
The warm front will push north, into western Washington, on
Monday, with a mild southwesterly flow aloft returning
spring-like conditions to western Oregon. The warm-up will
be short-lived, with a cold front sweeping onshore, with
more rain and cooler temperatures, Tuesday. A weak
upper-level trough will keep a chance of showers over mainly
the northern half of western Oregon on Wednesday, as the
flow aloft turns more westerly.
The long-range computer models have been all over the board
with their projections, beginning the middle of next week,
with the latest guidance building a ridge of high pressure
over the west coast for a return to warmer weather. Some of
the long-range guidance, however, drop a quick cold trough
over the region, so the forecast beyond next Wednesday is
still very much in question. I will broad-brush it for now
and and lean temperatures towards climatological normals.
Sat (13 Mar): Showers Decreasing Late. Snow Level 1500 Feet...Rising to 2500 Feet. 37/51
Sun (14 Mar): Mostly Cloudy North...Chance of Light Rain. Partly Cloudy South. 33/58
Mon (15 Mar): Considerable High Clouds and Mild. 38/63
Tue (16 Mar): Rain Likely and Cooler. 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): Partly Cloudy. 37/57
Fri (19 Mar): Partly Cloudy. 37/58
weather at oda.state.or.us
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