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Area forecast discussion 
National Weather Service Spokane Washington
353 am PST Sat Feb 6 2016

Synopsis...
today will be breezy with rain and snow showers over the
mountains of the Idaho Panhandle and over the Cascades. Strong
high pressure will build over the Pacific northwest Sunday
bringing dry weather and light winds. Mild high pressure is
expected for the first half of the week. The chance for light rain
will return Thursday, Friday, and Saturday.



&&

Discussion...

Today: a narrow band of precipitation (along a quick moving
frontal system) will impact the Idaho Panhandle early this
morning. As of 2 am, moderate snow was falling over the mountains
of Shoshone County above 3500 feet. Dot cameras at Lookout Pass
showed accumulations on Interstate 90 at 4700 feet. The most
significant snow at Lookout Pass will occur between now and
sunrise with 2 to 4 inches expected before snow decreases to snow
showers by mid morning. Post frontal snow showers will also occur
over the northern Cascades early this morning. Westerlies of 45 to
55kts at 700mb will push some of these convective bands as far
east as plain, Mazama, Twisp, and upper portions of Lake Chelan.
However, accumulations this morning should be an inch or less
given the mild temps and transient nature of these showers. Even
web cameras at Stevens Pass suggest the snow is having a tough
time accumulating so the Winter Weather Advisory for the east
slopes of the northern Cascades will be cancelled.

Breezy southwest winds will make it feel chilly today despite
above average temperatures. A few wind sensors gusted into the
40-45mph range with the passage of the cold front early this
morning, but the gustiness has abated a bit over the Palouse, West
Plains, and upper Columbia Basin. Our surface pressure gradients
will relax through the day today, but we may see a resurgence of
gusts to 35 mph around mid morning following sunrise. By early
evening, winds region-wide should be 5 mph or less as surface high
pressure quickly becomes established under a building upper ridge.

Tonight and sunday: our upper ridge will have a good deal of mid
and upper level moisture associated with it tonight into Sunday.
Looking at model soundings from the GFS and NAM, it is tough to
tell how thick clouds will be tonight into Sunday. The sounding
carry a good deal of moisture, but don't saturate suggesting
transient bands of clouds. A bit of very light precipitation is
depicted by the NAM and GFS Sunday afternoon and evening over the
Cascades, Okanogan Highlands, and northeast Washington mountains.
A 20-30 percent chance of light rain and snow has been added to
the forecast with Little Mountain snow accumulation expected.
/Gkoch

Sunday night through friday: models continue to show an upper
ridge building Monday and Tuesday. This will lead to strengthening
temperature inversions with areas of low clouds and patchy fog
forming in the valleys. Above the inversion mostly clear skies and
mild conditions will occur in the mountains as 850mb temperatures
rise into the 5-10c range. The Palouse, Lewiston area, possibly
extending west towards Ritzville will benefit from easterly
downslope boundary layer winds which keeps these areas out of the
low clouds with very mild temps in the lower to mid 50s. A few
record highs are possible. The ridge begins to weaken on Wednesday
however mild temperatures will continue. Thursday and Friday an
upper trough begins to approach the Washington and Oregon coast.
Models disagree with the details of when the next round of
potential precipitation arrives so did not make many changes.
Prevailing southwest flow however should result in a continuation
of mild temperatures and high snow levels when precip does arrive.
Jw

&&

Aviation...
12z tafs: strong mixing behind a departing cold front will
disperse the low clouds that have plagued the region for days. VFR
conditions are expected at the taf sites today and most of
tonight. There may be a bit of fog development in the sheltered
areas of northeast Washington and north Idaho overnight into
Sunday morning, but that is at the outer portions of this 24 hour
taf. /Gkoch

&&

Preliminary point temps/pops...
Spokane 40 28 40 30 45 31 / 10 0 10 10 0 0
Coeur D'Alene 40 26 39 31 46 32 / 20 0 10 10 0 0
Pullman 42 30 44 34 50 35 / 0 0 10 10 0 0
Lewiston 50 32 50 37 52 36 / 0 0 10 10 0 0
Colville 39 27 36 30 41 31 / 10 0 10 10 0 0
Sandpoint 39 27 36 30 41 32 / 30 10 10 10 0 0
Kellogg 36 26 37 31 45 32 / 60 10 10 10 0 0
Moses Lake 46 29 43 29 45 31 / 0 0 10 10 0 0
Wenatchee 42 29 38 30 41 31 / 0 0 10 10 0 0
Omak 40 26 34 29 37 29 / 0 0 10 10 0 0

&&

Otx watches/warnings/advisories...
Idaho...none.
Washington...none.

&&

$$

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