396
FXUS65 KMSO 301845
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
1245 PM MDT Tue Apr 30 2024

.DISCUSSION...An moist and unstable atmosphere across the
Northern Rockies will keep a mix of snow, graupel, and rain
showers persisting through the day and overnight for the majority
of western Montana and north central Idaho. A few breaks of
sunshine will be possible between showers, but overall we expect
the unsettled nature of the weather to persist through at least
Friday.

A more focused area of moisture and colder air will sink south
out of Alberta on Wednesday and will traverse along the Divide
through Thursday morning. In doing so, accumulating snow will be
likely immediately along the Divide. There is a 78% probability
of at least 2 inches of snow accumulating on Highway 2 over Marias
Pass, and a 45% probability of 4 inches, Wednesday afternoon
through Thursday morning. A Winter Weather Advisory has been
issued to address this potential. Lesser amounts will be possible
for other locations hugging the Continental Divide.

Conditions will once again remain unsettled both Friday and
Saturday. By Sunday, the region is looking at yet another
troughing pattern; one that shows hints of lasting through next
weekend. Appreciable moisture will be a result of this pattern,
though anyone hoping for a prolonged window of dry weather or a
warm up in temperatures is likely going to be disappointed.


&&

.AVIATION...A well defined shortwave trough, located over
northeastern Oregon early this afternoon, will shift eastwards
towards central Montana by 8 am MDT Tuesday morning. On the back
side of this trough, several weak embedded shortwaves will keep
shower activity going. The west-central and southwest Montana, and
SMN terminals have the best chance for snow and graupel showers,
and may be accompanied by gusty winds to to 25 knots. On
Wednesday, multiple waves will rotate counter-clockwise around the
stationary upper level trough over southern Alberta and
Saskatchewan into northwest Montana. This will keep persistent
mountain snow showers going with reduced ceilings, especially in
the Glacier National Park region, and in the vicinity of the Swan
and Mission Ranges. The remainder of the region will experience an
uptick in afternoon showers with gusty winds.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory from 4 PM Wednesday to 9 AM MDT Thursday
     for West Glacier Region.

ID...None.
&&

$$