Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 201906
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
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...
ID...None.
WA...Winter Weather Advisory until 11 PM PST this evening for East
     Slopes Northern Cascades.

&&

$$




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