Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 171124
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
424 AM PDT Tue Sep 17 2019

.SYNOPSIS...
Cool, wet fall weather will persist through mid week as a pair of
weather systems slowly make their way across the Inland Northwest.
A wet storm will arrive today with widespread rain and continued
showery weather into Wednesday. Aside from a few showers over
the Idaho Panhandle, drier, breezy and more seasonal weather
is expected Thursday through Saturday. A return of to unsettled
is expected by Sunday.

&&

.DISCUSSION...

Today through Wednesday night: Considerably cooler and unsettled
interval as large upper level trof of low pressure influences
Eastern Washington and North Idaho. Upper level jet stream bounding
the outer edges of the large trof are positioned overhead this
afternoon allowing for some gusty south and southwest winds today
and mainly during the afternoon that may precede the rain or
accompany it for a spell. Otherwise, this trof gets reinforced with
a closed low circulation dropping down from the northwest and
nesting in the upper level trof that parks a considerable cold pool
of air reflected in 500mb temps in the -20 to -22 range overhead
Wednesday that will steepen lapse rates and allow for the mention of
slow moving, and potentially training, surface based showers and
thunderstorms Wednesday afternoon and early evening. With this in
mind have highlighted the potential hazards of lightning, downpours,
and localized flooding for Wednesday in social media posts.
Lingering low level moisture from past and expected rainfall will
allow for some late night and early morning fog in the more
favorable areas such as the northern valleys.

Thursday through Friday: The upper trough axis will very slowly
move eastward over Idaho on Thursday, and toward the Continental
Divide on Friday. With cyclonic flow aloft remaining over the
region, a few showers will be possible during this timeframe,
favoring far eastern WA and into Idaho. A few showers will also be
possible along the Cascade crest. High temperatures will likely
remain in the 60s to low 70s across the region, or roughly 5 to 10
degrees cooler than normal.

Saturday: Saturday will bring the best chance of widespread drier
weather as the eastern Pacific ridge builds into the region.
Can`t rule out an isolated shower over the Idaho Panhandle though.
While temperatures should warm a couple of degrees over
Thursday/Friday, they will still remain below normal.

Sunday through Tuesday: Unsettled weather is likely to return
early next week as the next weather system arrives, flattening the
upper ridge. Forecast confidence remains low in the timing and
strength details for next week, as ensemble members diverge
significantly.
Dang

&&

.AVIATION...
12Z TAFs: Low cigs are expected to linger over KGEG/KSFF/KCOE
this morning, with remaining sites mostly VFR this morning.
The next weather system is bringing  light showers to the
Cascades this morning and should bring rain to KEAT and KMWH
late this morning. KEAT cigs could approach MVFR Tuesday
evening. The rain will reach the Spokane area sites later in this
afternoon but conditions should remain VFR.  /Pelatti


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        63  47  62  43  65  45 /  40  80  60  30  10  10
Coeur d`Alene  63  47  61  42  64  43 /  20  70  70  30  20  10
Pullman        64  44  62  41  62  41 /  20  70  60  40  40  20
Lewiston       69  53  68  50  67  51 /  20  70  70  50  40  20
Colville       64  40  64  35  70  38 /  60  90  70  30  10   0
Sandpoint      61  46  59  41  64  42 /  20  70  80  30  20  10
Kellogg        61  50  59  45  62  46 /  20  60  70  40  40  30
Moses Lake     63  45  68  44  72  46 /  80  60  30  30   0   0
Wenatchee      60  51  64  50  69  52 /  90  70  40  20   0   0
Omak           61  49  63  45  70  48 /  90  90  50  20   0   0

&&

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

&&

$$


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