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Area forecast discussion 
National Weather Service Spokane Washington
1021 am PDT Wednesday Sep 17 2014

Synopsis...
another warm day is in store for the inland northwest with
afternoon temperatures in the 80s. A weak cold front will move
through Washington and Idaho on Thursday. The front will push
temperatures closer to normal and bring the potential for widely
scattered showers on Thursday. A high pressure ridge will return
Friday and promote warm and dry weather through the weekend.



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Discussion...
today through Thursday night...the weather pattern will become
more unsettled across the inland northwest as the ridge of high
pressure gets nudged to the east by an approaching upper trough.
Regional radar imagery shows some light returns moving northeast
across western Washington this morning. The trajectory is more north than
east so shower activity is expected to remain close to the Cascade
crest today although there may be some sprinkles for the Wenatchee
area and the Okanogan Highlands today. The energy associated with
this system is splitting, with the bulk of it remaining in the
southern stream as a low closes off and drifts south along the
West Coast. The secondary northern stream will eventually slide
east tonight, bringing some showers to the northern mountains. The
better chance for showers and even a few thunderstorms will be
across the eastern half of the forecast area on Thursday. The
north-south orientation of the trough will allow the very warm air
to remain in place today. Max temperatures will be close to
tuesdays readings, which are about 10m degrees above seasonal
normals. A cold front will move through late in the day Thursday
bringing cooler conditions but the timing will mean one more day
of above normal temps. Breezy conditions will develop behind the
front with gusts to around 25 mph across the basin. Drier air
behind the front will limit any lingering showers to the Idaho
Panhandle Thursday night. /Kelch

Friday through sunday: the models are in very good agreement
Friday through the weekend...developing a Rex block type feature
over the western U.S. Some residual mid-level moisture in the
northwest flow may produce a small chance for showers over the
mountains of the north Idaho Panhandle and Cascade crest on Friday.
However, model soundings suggest warming and drying aloft will
limit precipitation chances to the morning hours. Increasing 500mb
heights Friday afternoon into the weekend will shunt the storm
track well north of the region. Above average temperatures will
return by Saturday. Afternoon readings in the upper 70s to mid 80s
will be common Saturday, and Sunday will likely feature mid 80s to
upper 80s. The last weekend on the official Summer calendar will
actually feel like Summer. Fall officially arrives on Monday the
22nd with the autumn equinox. /Gkoch

Monday through wednesday: this is shaping up to be a transition
period for the region as a trough system will begin to press into
the region from the Gulf of Alaska. The ridge pattern will linger
over the region Monday through Tuesday. This will allow for
precip free period. By late Tuesday, the ridge begins to breakdown
and moisture begins to push over the Cascades area. The precip
will continue to cross the inland northwest into through
Wednesday. Winds are expected to become breezy as the trough
moves through the region. Temperatures are expected to decrease
to near season normals. /Jdc

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Aviation...
18z tafs: high pressure shifts east and the southwest flow brings
moisture and energy up from the south today. A cold front will
move through the forecast area Thursday. Middle and high level
clouds will thicken with a slight chance of showers for the
Cascades. A few sprinkles may slip by eat after 06z Thursday.
Some smoke from near wildfires may lower visible toward MVFR
conditions around puw and lws Wednesday morning. Otherwise look
for VFR, dry conditions. /Mjf

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Preliminary point temps/pops...
Spokane 84 58 80 56 76 51 / 10 10 20 10 10 0
Coeur D'Alene 85 55 80 55 76 50 / 10 10 30 30 10 0
Pullman 86 54 80 53 76 49 / 10 10 20 10 10 0
Lewiston 91 62 86 59 82 56 / 10 0 20 20 10 0
Colville 85 54 81 51 80 47 / 10 20 30 20 10 0
Sandpoint 80 49 75 51 73 46 / 10 10 30 30 20 10
Kellogg 83 54 76 53 72 50 / 10 10 30 30 20 0
Moses Lake 88 59 85 56 84 52 / 10 10 10 10 0 0
Wenatchee 87 64 82 61 83 58 / 10 20 20 10 0 0
Omak 88 60 82 55 82 49 / 10 20 30 20 10 0

&&

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

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