642
FXUS65 KTFX 061137
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
437 AM MST Sat Dec 6 2025

Aviation Section Updated.

.KEY MESSAGES...

- Areas of snow will continue today, with cold temperatures over
  the northern portions of North Central MT.

- Almost daily chances for mountain snow are expected Sunday
  through Friday, with a chance for lower elevation snow mid week.

- There is a high potential for strong winds over much of area
  Monday through Wednesday.

&&

.DISCUSSION...
/Issued 409 AM MST Sat Dec 6 2025/

 - Meteorological Overview:
Overall, areas of light snow continue to affect portions of the
CWA this morning. The heaviest snowfall is falling along the
divide and across the mountains of Southwest MT, mostly in the
West Yellowstone area. The snow is likely to continue into the
evening hours in the West Yellowstone area, so that warning was
extended a few hours. Otherwise, there no changes to the other
current winter statements currently in effect for today.

One concern for today is how far south will the cold air make it.
As of 3 AM, the cold air was generally north of a Dutton to Loma
line. This cold air could sag a bit further south into the Great
Falls area later this morning, before starting to shift back
further north tonight. Additionally, areas of dense fog will also
affect portions of North Central MT through Sunday morning.

For Sunday through Tuesday, strong southwesterly winds are
forecast to develop over the CWA. This will result in some fairly
mild air moving into the CWA at lower elevations for early next
week. Additionally, there is a good potential that high wind
statements will be needed come Monday night into Wed for much of
the CWA.

Wednesday through next Saturday...Colder air will try to move
southward Wed/Thu behind the storm system that produces all the
wind. The main question is how far south does the cold air make
it, and how fast does the cold air retreat late next week. A
period of snow is likely Wed into Thu over much of the CWA along
with some cold temperatures. However, on Friday, some models want
the cold air to begin to retreat already, with a return of mild
air by Saturday. This might be a bit too fast, but it is not out
of the question either. So do expect some significant changes in
daily temperatures late next week, with afternoon highs possibly
being even warmer than currently forecasted.

 - Forecast Confidence & Scenarios:
The main concern for the next few days will be the wind potential
Mon into Wed. Some models prog a strong wind event over portions
of North Central MT. Right now, much of North Central MT has over
a 60 percent chance for high winds on Tuesday, with the windy
locations along the Rocky Mountain Front and in the Cut Bank area
having over an 80 percent chance for high winds.

The second concern for late next week will be the timing of the
return of the cold air, along with how far south does it go, and
how fast does it retreat. The forecast models all vary on the
details, thus confidence is on the low side right now on the daily
details of how cold/snowy/how fast it will warm up for late next
week. Brusda

&&

.AVIATION...
06/12Z TAF Period

Main concerns today will be areas of dense fog over North Central
MT and the light snow. Expect areas of dense fog through Sunday
morning over North Central MT. It will be sporadic in terms of
affecting terminals, but 1/4sm in dense fog will be possible for
short periods of times as the fog moves in/out. Otherwise, light
snow will also affect a good portion of the CWA today, especially
the mountains. Overall the snow will begin to diminish in coverage
area this evening. Mountains/passes will be obscured across the
CWA through the period. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  32  20  41  35 /  60  10   0  10
CTB  23  11  37  29 /  20  10   0   0
HLN  40  28  41  31 /  70  20  10  20
BZN  39  22  39  27 /  70  30  10  20
WYS  33  13  29  21 /  80  30  50  80
DLN  41  25  38  28 /  30  10   0  20
HVR  22   6  35  24 /  60  70   0  10
LWT  32  20  38  27 /  70  50   0  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 9 PM MST this evening for East
Glacier Park Region-Southern Rocky Mountain Front.

Winter Weather Advisory until 11 AM MST this morning for Bears
Paw Mountains and Southern Blaine-Eastern Toole and Liberty-
Elkhorn and Boulder Mountains-Fergus County below 4500ft-Hill
County-Northern Blaine County-Snowy and Judith Mountains-Upper
Blackfoot and MacDonald Pass-Western and Central Chouteau County.

Winter Storm Warning until 2 PM MST this afternoon for Big Belt,
Bridger and Castle Mountains-Little Belt and Highwood Mountains.

Winter Storm Warning until 9 PM MST this evening for Gallatin
and Madison County Mountains and Centennial Mountains.

Winter Storm Warning until 5 PM MST this afternoon for Northwest
Beaverhead County.

&&

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