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000
FXUS66 KOTX 122241
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
341 PM PDT Fri Apr 12 2024

.SYNOPSIS...
The upcoming weather into the weekend will feature a few chances
of mostly mountain showers and thunderstorms with a warming
trend. High temperatures for much of the area will climb into the
70s over the weekend. A cold front will bring a return of cooler
and showery weather early next week. Cold front passage will bring
windy conditions Sunday night through Monday.

&&

.DISCUSSION...

Tonight through Saturday night: An upper level low`s positioning off
the Northern California and Oregon coast is allowing for diffluent
flow aloft and low level southerly flow of moisture along with some
instability this afternoon and tonight. Disturbances rotating around
the outer edges of this low will work their way north and
northeast. As such a minor mention of showers and thunderstorms
remains in place over the far southeast roughly south and east of a
line from Ritzville to Couer d`Alene to Clark Fork this afternoon
and tonight. After tonight and through Saturday night the upper
level offshore low is positioned further south near California and
in such a manner as to promote pumping up of an extremely negatively
tilted upper level ridge over Eastern Washington and North Idaho
which will suppress upward motion. In addition a good amount, but
not all, of the moisture will be diverted into Oregon. Thus this
suppression of upward motion and decrease in moisture should result
in a generally dry forecast with some cloud cover overhead Saturday
coupled with a decreasing cloud cover trend Saturday night. The
earlier mentioned persistent southerly flow will promote a warming
trend through the weekend.
/Pelatti

Sunday through Friday: Sunday will be warm, dry, and increasingly
breezy in the afternoon as a cold front advances toward the Inland
Northwest. Recent forecasts indicate a slower progression of the
cold front, but surface pressure gradients suggest breezy
conditions will develop Sunday afternoon. There`s a slight chance
(20%) of thunderstorms in southeastern Washington and the southern
Panhandle Sunday afternoon as a trough from California sends a
disturbance our way. These storms could produce small hail, gusty
outflow winds, and brief heavy downpours. Winds will intensify
with the passage of the cold front Monday morning, and the
continuous influx of cold air will maintain windy conditions for
much of the day. Exposed ridgetops in the Cascades and the
Waterville Plateau face a 20-40% chance of experiencing gusts
exceeding 45 mph Monday afternoon. Monday will remain dry,
increasing the risk of grass fires. Blowing dust may become an
issue in the Columbia Basin and Waterville Plateau due to the
gusty winds.

After the cold front passes, snow levels will drop sharply,
bringing the possibility of light snowfall down to valley floors
by Tuesday morning. Minimal to no accumulation is expected in
lowland areas, and the risk of significant snowfall in the
mountains is low. Stevens Pass has a 50% chance of receiving at
least 3 inches of snow, while Snoqualmie Pass has a 80% chance of
the same. In the event that the convergence zone aligns over a
pass, heavier snowfall rates may cause minor travel disruptions,
but generally, road temperatures should be warm enough to lessen
impacts. Following the initial temperature drop from the system
arriving on Monday, cooler weather will endure throughout the
week, accompanied by brisk north winds and occasional chances
(30%) of non-impactful showers. /Butler

&&

.AVIATION...
00Z TAFS: Slight chance of thunderstorms between 0-6Z Saturday
over southeast portion of the aviation area (0-3z for Pullman and
0-6z for Lewiston). Otherwise VFR conditions to prevail with
various mostly middle and high cloud drifting overhead.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in
persistent VFR conditions, Exception may be for MVFR conditions at
times with any thunderstorms that develop roughly south and east
of a line from Ritzville to Coeur d`Alene to Clark Fork between
0-6z.


-----------------------

Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance

For additional probabilistic information for NWS Spokane airports,
please refer to the Aviation Dashboard on our webpage:
https://www.weather.gov/otx/avndashboard

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        43  69  45  75  42  62 /  10   0   0   0   0  10
Coeur d`Alene  43  68  44  73  43  59 /  10   0   0  10   0  10
Pullman        44  70  47  70  42  58 /  40   0   0  20  20  10
Lewiston       49  76  52  77  48  66 /  40   0   0  20  20   0
Colville       37  71  41  76  41  64 /   0   0   0   0   0  10
Sandpoint      41  66  43  72  43  58 /  10   0   0  10   0  30
Kellogg        46  68  49  72  44  57 /  20   0   0  20  10  20
Moses Lake     41  74  46  80  44  66 /   0   0   0   0   0   0
Wenatchee      46  72  49  76  47  62 /   0   0   0   0   0   0
Omak           42  73  45  76  44  65 /   0   0   0   0   0   0

&&

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

$$