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000
FXUS65 KMSO 241952
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
152 PM MDT Wed Apr 24 2024

.DISCUSSION...Isolated showers will push through the Northern
Rockies, mainly south of I-90 today. In general though, today
will be another warm and dry day with breezy southwest winds.

Tomorrow clouds increase with temperatures cooling slightly in
response. Shower activity increases but still remains mostly south
of I-90. Isolated thunderstorms will also be possible in the
southern Clearwater Mountains, east across Lost Trail Pass, and
into southwest Montana.

Friday a big change in the weather pattern is coming. A weather
system is expected to track across southwest MT and Lemhi County
ID. The models do show energy splitting with the northerly track
along the Canadian border and the southerly track, which has the
largest model spread, from Utah to Wyoming. If a 700mb closed low
was to form and the track is a typical spring Yellowstone Low this
would potentially have high impacts for southwest MT and Lemhi
County ID. The high impact scenario is low probability,
represented by around 20% of model solutions.

Our current forecast, which is based off the higher probability
forecast, has snow accumulations above 6000 feet of around 2 to 4
inches in southwest MT and Lemhi County ID. For the rest of the
region expect light snowfall above 6000 feet, with a greater than
50% probability of 0.25" of rain from I-90 and points south.

The high impact scenario would allow for heavy wet snow
accumulations greater than 6 inches above 6000 feet in Silver
Bow, Granite, Powell, Deer Lodge, and Lemhi Counties. Expect
periods of winter driving conditions overnight Friday. Elevations
in those locations from 4500 to 6000 feet would experience periods
of moderate snowfall causing roads to become snow covered at
times.

Sunday through Tuesday, a showery and cooler weather pattern will
continue. Be prepared for another spring weather system Wednesday
into Thursday, potentially bringing lower snow levels than the
upcoming Friday system.

&&

.AVIATION...Today, the development of southwesterly flow aloft
ushers in another warm day. Moisture originating southwest of the
region is set to arrive this afternoon, resulting in the gradual
buildup of cloud cover and the onset of showers primarily south of
I-90. In northwest Montana, the likelihood of experiencing wind
gusts of 22 knots or greater this afternoon exceeds 80%, while
similar gusts are also possible in conjunction with showers south
of I-90.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$