Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 212357
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
457 PM PDT Thu Sep 21 2017

.SYNOPSIS...
Drier and warmer weather starts Friday and persists into next
week as high pressure gradually builds over the region.

&&

.DISCUSSION...

Tonight through Saturday night...Water vapor imagery today showed
a moist boundary producing a swath of showers over east central
Washington. This has dissipated and been replaced by spotty
convective showers, mostly over the northern half of the area,
where mid level moisture continues to surge southwest along the
positively tilted trough. With the sun breaking through in spots
and 500 mb temperatures around -23 C some intense showers continue
to be possible this afternoon. Not enough instability exists,
though, to expect much in the way of thunderstorms. These showers
will dissipate with the loss of daytime heating. Gusty north winds
in the Okanogan Valley will remain elevated through the evening
and into Friday morning. We`ll also see temperatures dip into the
lower 30s and frost will be possible in spots overnight. As the
low slowly transits east on Friday we finally get into some drier
mid level flow which will keep us dry on Friday and into the
weekend. Winds will decrease by the evening as well. On Saturday
the upper level ridge continues to edge inland, bringing mostly
dry northerly flow for increasing temperatures and the only
possibility of showers over the ID/MT border. /bw

Sunday through Thursday...A flat ridge is over the region
initially with a pair of weak disturbances moving through the
area. Most of the moisture from these waves tracks north of the
area, but just enough to warrant a slight chance of showers for
the northern mountains and Idaho Panhandle for early next week.
These waves should also bring an abundance of mid and high level
cloud cover to the region. The ridge amplifies over the area
Wednesday and Thursday resulting in mostly clear skies and a
continued warming trend. Highs Thursday may reach the mid 70s to
near 80 which would be around 5-8 degrees above normal. JW

&&

.AVIATION...
00Z TAFS: Widely scattered showers will linger through 02z then
drier air begins to slowly work in from the north. There is a
small potential for brief MVFR cigs through 05z along with
pockets of fog in the sheltered valleys but any coverage will be
patchy and shallow and increasing north to northeast winds after
06z will lead to VFR skies. /sb

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        38  60  40  62  42  64 /  10   0  10  10  10  10
Coeur d`Alene  36  59  36  62  38  65 /  10   0  10  10  10  10
Pullman        34  58  38  60  39  63 /  10  10  10  10  10  10
Lewiston       41  64  42  66  44  69 /  10  10  10  10  10  10
Colville       36  66  36  68  38  68 /  20  10  10  10  10  10
Sandpoint      34  59  34  60  35  63 /  20   0  10  10  10  10
Kellogg        33  54  34  57  35  61 /  20  10  10  10  10  10
Moses Lake     40  68  40  69  43  71 /  10  10  10   0  10  10
Wenatchee      45  67  46  69  48  71 /  10  10  10   0  10  10
Omak           43  67  40  70  42  73 /  10  10  10   0  10  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.

&&

$$



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