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Area forecast discussion 
National Weather Service Spokane Washington
1106 am PST Sat Dec 20 2014

Synopsis...
a more active weather pattern will continue into early next week.
Another wet and robust weather system will bring snow to the
mountains with mainly rain for the valleys today and tonight.
Temperatures are expected to remain above average through early
next week...before dropping down toward normal values by Christmas
day.




&&

Discussion...
morning update: messy forecast pattern. A warm front is draped
across the region this morning and impulses riding along it will
bring occasional rain and snow. Short-range guidance, such as the
hrrr and hi-res NAM, have been showing one wave of precipitation
pushing across the region from mid-morning to early afternoon,
followed by brief break, before another broader wave of
precipitation comes in from mid to later afternoon into this
evening. That precipitation comes with the mid-level shortwave
riding in on the nose of the jet stream, before things begin to
dry out from the west overnight into Sunday morning so that by
afternoon the main precipitation will be near the Cascades crest
and over Idaho, particularly the central Panhandle mountains,
through the Blue Mountains.

Winter weather advisories remain in place for the Cascade
mountains and valleys, with the most significant snows expected
both near the crest and north of Lake Chelan. This is where some
of the colder air remains, though even the most guidance that
keeps snow levels lowest tends to bring them up a bit through this
afternoon into tonight. Places like the Methow Valley, including
areas near Twisp, have reported around 4 inches of snow so far and
spots could pick up another 4 to 6 inches through this evening,
with locally higher amounts in the higher terrain, before the
rates start to wane as the drier air comes in overnight into
Sunday morning.

Winds are expected to increase with this system, especially
overnight into Sunday when drier air and mixing comes with the
mid-level disturbance riding that jet. Right now this is not
prime timing for thinking any wind highlights will be needed. But
it will be monitored. /J. Cote'

&&

Aviation...
18z tafs: periods of mainly rain expected around taf sites from
mid morning to early afternoon and again from late afternoon into
tonight, before precipitation starts to wane from the west
overnight into Sunday. Look for MVFR/IFR conditions. Winds are
expected to increase later this evening into Sunday. We will have
to monitor for possible llws, if the atmosphere fails to mix
effectively this evening into Sunday morning. /J. Cote'




&&

Preliminary point temps/pops...
Spokane 41 40 47 34 40 32 / 90 100 30 30 20 10
Coeur D'Alene 39 37 46 33 40 31 / 90 90 40 50 30 20
Pullman 43 40 51 38 45 34 / 90 100 80 50 20 10
Lewiston 44 42 56 41 49 36 / 80 100 70 70 20 10
Colville 38 35 41 29 37 29 / 100 100 20 30 10 20
Sandpoint 37 35 41 32 37 30 / 90 100 60 60 30 20
Kellogg 38 35 43 34 38 30 / 90 100 90 90 40 20
Moses Lake 42 41 50 35 44 34 / 90 80 10 10 10 10
Wenatchee 38 37 46 35 42 33 / 90 90 30 20 10 20
Omak 37 34 40 29 37 29 / 100 80 10 10 10 10

&&

Otx watches/warnings/advisories...
Idaho...none.
Washington...Winter Weather Advisory until 11 PM PST this evening for east
slopes northern Cascades.

&&

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