915
FXUS65 KTFX 032207
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
307 PM MST Wed Dec 3 2025

.KEY MESSAGES...

 - Widespread snow expected Thursday evening through Saturday
   afternoon with the heaviest amounts in the mountains.

 - An active pattern continues through next week with warmer and
   windier conditions possible.

&&

.DISCUSSION...

 - Meteorological Overview:

Calm conditions will continue through the rest of today with
increasing cloud cover expected as the evening progresses.
Thursday will start off dry before the first shortwave trough
moves over the area in the afternoon kicking off the initial
snowfall that will primarily focus on the mountains. On Friday,
a second, stronger shortwave will move into the region bringing a
chance for more widespread snow at lower elevations Friday night
into Saturday afternoon. The combination of these two shortwaves
over the two day period will allow for heavy snow in the mountains
and lighter but still impactful snow at lower elevations across
most of the region.

Northwest flow aloft continues through the start of next week
allowing for unsettled conditions to continue through at least
last Wednesday. Additionally, there is growing confidence in
stronger Chinook winds along the Rocky Mountain Front early next
week which is expected to bring some warmer temperatures back to
the lower elevations of north-central Montana.


 - Forecast Confidence & Scenarios:

Lower Elevation Snow Thursday through Saturday:

Light lower elevation snow is possible with the Thursday shortwave
but the main event for lower elevations will be Friday afternoon
through Saturday afternoon with the arrival of the second
shortwave. With the second system, a widespread 1-2 inches is
possible across a good portion of north-central Montana except the
Golden Triangle which is set to miss most of the snowfall with
this event. As of right now, there are a couple areas along the
lower elevations which would be candidates for higher snowfall
amounts, particularly along the Highway 200 corridor between Great
Falls and Lewistown, the Smith River Valley, and the Gallatin
Valley. Confidence was not high enough to add them to the initial
Winter Storm Watch but these areas will need to be monitored with
future updates as increases in snowfall amounts could justify
adding these zones to the watch or eventual warning. But otherwise
most of the lower elevation snowfall looks to be advisory level
at this point with only minor impacts expected.


Heavy Mountain Snow Thursday through Saturday:

Confidence continues to increase in the potential for significant
snowfall along the mountains of central and southwest Montana with
the greatest impacts expected along the Continental Divide and
ranges of central and southwest Montana. As such a Winter Storm
Watch has been issued for Thursday evening through Saturday
afternoon. Broadly speaking, 6 to 12 inches is possible with the
ridgetops potentially seeing amounts greater than a foot.


Travel Impacts Thursday through Saturday:

By far, one of the biggest concerns with this system will be the
timing and how it impacts the Thursday evening, Friday morning,
and Friday evening commutes. With the initial snowfall on
Thursday, depending on road temperatures, there will likely be
some initial melting of the first few flakes. When this moisture
refreezes as the night goes on the concern will be patches of ice
forming and then receiving more snow as the event continues
creating very slick roads. Additionally, some periods of moderate
to heavy snowfall are possible particularly with the initial push
on Thursday evening and again with the arrival of the second
shortwave on Friday afternoon/evening. This could lead to periods
of reduced visibility which will add to the potential for
hazardous driving conditions.

In particular, there is great concern regarding the impacts
possible along I-90 from Belgrade to Bozeman Pass. Snowfall
probabilities in Bozeman proper were not enough to warrant
including Gallatin Valley in the Winter Storm Watch but minor to
moderate impacts are still possible in the area due to slick roads
and brief periods of moderate to heavy snowfall, particularly on
the far eastern side of the Gallatin Valley heading towards the
pass.

Additional mountain passes and roads that might experience
significant impacts include, but are not limited to, Marias Pass,
Kings Hill Pass, Deep Creek Pass, and Highway 191 south of Bozeman
to the Idaho border. If heading out, motorists need to be prepared
for rapidly changing and deteriorating road and weather
conditions and it is advised to carry chains as well as an
emergency kit. -thor


&&

.AVIATION...
03/18Z TAF Period

Low clouds will be a concern at KBZN through 03/20Z before
ceilings start to lift. Dense freezing fog and LIFR/VLIFR
conditions will remain at KCTB through at least 03/19Z. The
latest hi-res models show slow clearing with a return to VFR
conditions by 03/21Z, however, there is a 20% chance that dense
fog might linger a couple more hours should adequate mixing fail
to occur.

Beyond that, VFR conditions are expected across the region with
some breezy conditions across north-central Montana this afternoon
through Thursday morning. Periods of LLWS are possible at KLWT
after 04/06Z. -thor

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  23  38  24  35 /   0  30  30  50
CTB  21  35  20  30 /   0  10  10  40
HLN  21  36  26  38 /   0  40  40  60
BZN  14  33  23  36 /   0  50  50  50
WYS   9  24  15  30 /  10  80  80  80
DLN  18  36  23  40 /   0  20  30  40
HVR  10  35  18  30 /   0  20  20  40
LWT  18  36  21  34 /   0  30  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from late Thursday night through Saturday
afternoon for East Glacier Park Region-Northwest Beaverhead
County-Southern Rocky Mountain Front.

Winter Storm Watch from Thursday afternoon through late Friday
night for Big Belt, Bridger and Castle Mountains-Gallatin and
Madison County Mountains and Centennial Mountains-Little Belt
and Highwood Mountains.

&&

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