170
FXUS65 KTFX 020340
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
840 PM MST Mon Dec 1 2025

.KEY MESSAGES...

 - Another system will bring widespread snowfall to the area
   tonight through early Wednesday morning.

 - This afternoon through the end of the work week it will
   gradually warm up.

 - Another system will move through Friday and Saturday and bring
   precipitation with details uncertain at this time.

&&

.UPDATE...

The current forecast remains on track for the overnight hours. A
little shortwave aloft is pulling current light snow in
Central/Southwest MT off to the southeast. There will be a brief
lull in snow before another shortwave in Northwest Montana right
now, brings another round of snow to the region early Tuesday
morning. A boundary pushing south throughout the day Tuesday will
bring steadier snowfall, especially in the mountains where they
can get snowfall rates of 0.5" per hour. Gusty winds along the
Rocky Mountain Front overnight still can produce localized blowing
and drifting snow. -Wilson

&&

.DISCUSSION...
/Issued 426 PM MST Mon Dec 1 2025/

 - Meteorological Overview:

This afternoon there is an upper-level ridge over North-central,
Central, and Southwestern Montana. This will allow temperatures to
warm up with mostly dry weather. Due to the ridge building in over
the area briefly combined with a strong surface pressure gradient it
will be windy today. This will lead to some areas of localized
blowing snow through this evening. Tonight an upper-level trough
will move over North-central, Central, and Southwestern Montana.
This will bring snow to North-central, Central, and Southwestern
Montana. On Tuesday the upper-level trough remains over North-
central, Central, and Southwestern Montana. As a result the snow
will be off and on through early Wednesday morning with cool
temperatures.

On Wednesday the upper-level trough remains over North-central,
Central, and Southwestern Montana. This will slightly cool down
temperatures with mostly dry weather. On Thursday an upper-level
ridge builds in over North-central, Central, and Southwestern
Montana this will allow temperatures to warm up with mostly dry
weather. Friday through Saturday there will be northwest flow aloft
which will cool down temperatures slightly and bring precipitation
to North-central, Central, and Southwestern Montana. On Sunday an
upper-level ridge will move over North-central, Central, and
Southwestern Montana. This will bring warmer temperatures and dry
weather to the area. IG

 - Forecast Confidence & Scenarios:

Tonight through Wednesday morning there is greater than a 65%
chance for 2 inches of snow or greater along the Montana 200/US
Highway 87 Corridor between Great Falls and Lewistown. Across the
mountains of North-central, Central, and Southwestern Montana
there is greater than a 50% chance for 6 inches of snow or
greater.

For Friday into Saturday there is high uncertainty in the upper-
level pattern. For Friday into Saturday half of the clusters keep an
upper-level ridge over North-central, Central, and Southwestern
Montana. While the other half of the clusters have an upper-level
ridge to the west of Montana with northwest flow aloft. The
northwest flow aloft scenario would bring colder temperatures and
more precipitation to North-central, Central, and Southwestern
Montana. The upper-level ridge scenario would keep warm temperatures
with mostly dry weather across the area. IG

&&

.AVIATION...
02/00Z TAF Period

A series of weather disturbances moving through northwest flow
aloft will bring lowering cloud-bases and increasing mountain
obscuration this evening as areas of snow develop. A period of
snow and MVFR/IFR conditions will affect some southwest MT
terminals later this evening and overnight with MVFR conditions
becoming more widespread at most terminals later tonight through
Tuesday. Hoenisch

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  28  35  16  33 /  70  90  60   0
CTB  24  33   9  30 /  60  80  30   0
HLN  25  34  16  32 /  60  80  50   0
BZN  21  34  15  32 /  60  80  40   0
WYS  15  28   5  28 /  70  90  40   0
DLN  23  37  15  33 /  40  50  40   0
HVR  19  35   5  25 /  50  70  30  10
LWT  23  33  11  32 /  60  90  70  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 11 PM MST Tuesday for East Glacier
Park Region-Northwest Beaverhead County-Southern Rocky Mountain
Front.

Winter Weather Advisory from 5 AM Tuesday to 5 AM MST Wednesday
for Bears Paw Mountains and Southern Blaine-Cascade County below
5000ft-Fergus County below 4500ft-Gates of the Mountains-Helena
Valley-Judith Basin County and Judith Gap-Upper Blackfoot and
MacDonald Pass.

Winter Weather Advisory until 5 AM MST Wednesday for Big Belt,
Bridger and Castle Mountains-Gallatin and Madison County
Mountains and Centennial Mountains-Little Belt and Highwood
Mountains-Snowy and Judith Mountains.

&&

$$
http://www.weather.gov/greatfalls