774
FXUS65 KTFX 111617
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
917 AM MST Thu Dec 11 2025

.KEY MESSAGES...

- It turns colder later today as a cold front moves southward
  through Montana.

- A period of heavy snow is possible on Friday, mostly east of a
  line from Shelby to Belt.

- After a brief cool down Friday, it starts to turn warmer
  Saturday, and by Sunday, many areas over Central and Southwest
  MT will have afternoon temperatures in the 50s once again.

- Several days of windy conditions are expected next week over
  North Central MT.

&&

.UPDATE...

9 AM MST - Late morning update has been published; with the main
additions being adding mentions for freezing rain across portions
of the Central and North Central Montana plains, and adding the
Northern High Plains, Southern High Plains, Eastern Glacier,
Western Toole, and Central Pondera, Eastern Toole and Liberty,
and Eastern Pondera and Eastern Teton to the Winter Weather
Advisory through 3 PM MST this afternoon. The Arctic front has
been surging south across the North Central Montana plains ever
since ~8AM MST this morning, with the front currently beginning to
push into portions of Pondera and Chouteau Counties. Temperatures
are falling rapidly behind the front, with temperatures along the
Canadian border already in the teens to single digits. This
initially shallow Arctic air was undercutting a fairly mild
airmass, which was leading to a brief (less than 30 minutes)
period of freezing rain before a changeover over to snow. This
brief window of freezing rain is expected to translate south
across the remainder of the plains, with a light glaze of ice
developing on surfaces, especially elevated ones. All of the
Winter Weather Advisories have been updated to include this light
icing mention. Travelers are urged to be prepared for changing
conditions. If you live north of the US Hwy 12 corridor ... be
prepared for much colder temperatures by the evening commute as
compared to this mornings mild conditions. - Moldan

4:37 AM MST - Forecast was updated this morning to add the Great
Falls area to the high wind warning. Brusda

&&

.DISCUSSION...
/Issued 437 AM MST Thu Dec 11 2025/

 - Meteorological Overview:
The main concern this morning is the cold front that is forecast
to move southward through the CWA. As of 330 AM, the cold air will
still up in southern Alberta, near Lethbridge, and not moving
southward very fast. This is a concern, as a later arriving cold
front might not push as far south as currently forecast. (The
Helena/Townsend area...before moving back north.) Thus
temperatures from Great Falls southward will be mild today, with
some areas already close to 60 degrees. Additionally, the freezing
level this morning was over 9000 feet, thus it is going to take
some time for the air to cool not only at the surface, but aloft.
This could allow for more rain to fall, which could lower snow
amounts a bit. In terms of a flash freeze, it is possible, but
confidence is lower right now, as the cold air is just gradually
moving in over an hour or two, rather than a 15 min period right
now.

So for today, do expect some light snow, mostly late this morning
north of Highway 2 and towards this evening further south.
However, snow amounts will be on the light side, generally less
than inch at lower elevations...maybe 1 to 3 inches in the
mountains.

For tonight/Friday, the main concern will be how far south this
cold front makes it before it starts to move back northward on
Friday. Right now the front is forecast to move down to about a
Helena/Townsend line. This might be a bit far south, should the
front be slow to arrive. That being said, the cold front is
expected to move back northward by Friday afternoon as a warm
front. Areas just to the north of this frontal boundary will have
the highest chances for heavy snowfall on Friday. Right now, that
area is looking to be areas east of a line from Shelby to Belt.
Areas over the Plains west of this line will likely just get some
minor snow accumulations. East of this line, there is still the
potential for about a 5 to 10 inch snowfall at lower elevations
and a bit higher amounts in the mountains. Temperatures will be
colder over North Central MT, but mild air will continue to reside
over Southwest MT.

For Saturday and Sunday...expect warmer air to gradually move
northward through the CWA, starting in the Central areas on
Saturday and then moving through the northern portions of the CWA
on Sunday. Any light snowfall from the Friday storm should end
early on Saturday.

Monday through Thursday...the above normal temperatures will
continue through the first half of next week, before slowly
cooling a bit late next week. There is a good potential for
several days of windy conditions next week, with some periods of
strong winds possible over North Central MT. Also, scattered
showers will be on the increase, starting as rain early in the
week, then going more towards snow by late next week as
temperatures cool down a bit.

- Forecast Confidence & Scenarios:

Snowfall...the location of where the cold front ends up tonight
will have significant impacts on where the heavy snow sets up on
Friday. The further south the front pushes, the more likely the
heavy snow will fall over the eastern portions of North Central
MT. If the front stalls out along a line from Great Falls to
Lewistown, then just mainly the northern portions of North Central
MT will have the potential for heavy snow on Friday.

Strong winds early next week...There is already and 80 percent
chance that winds could exceed warning criteria along the Rocky
Mountain Front and in the Cut Bank area Mon and Tue and a 60
percent chance on Wed. Brusda

&&

.AVIATION...
11/12Z TAF Period

Strong winds will affect portions of Central MT this morning. Then
a cold front will move southward across North Central MT mostly
late this morning and this afternoon. Expect a surface wind shift
to the north, along with rain showers changing to snow showers.
Scattered snow showers are expected through the night across
Central MT. The scattered showers could make it as far south as
Ennis/Bozeman...but right now the thinking is generally that most
of the showers will just remain in the mountains around
Ennis/Bozeman. Otherwise, mountains/passes will be obscured across
the CWA through period. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  56   2  11   5 /  70  50  90  60
CTB  51  -4   4  -2 /  40  20  80  60
HLN  57  21  34  26 /  80  80  80  30
BZN  56  33  45  33 /  50  70  70  20
WYS  40  29  37  21 /  40  60  50  10
DLN  55  41  51  33 /  20  20  10   0
HVR  39  -7   0  -8 /  70  50  80  90
LWT  49   5  10   4 /  90  70 100  80

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 3 PM MST this afternoon for Bears
Paw Mountains and Southern Blaine-East Glacier Park Region-
Eastern Glacier, Western Toole, and Central Pondera-Eastern
Pondera and Eastern Teton-Eastern Toole and Liberty-Hill County-
Northern Blaine County-Northern High Plains-Western and Central
Chouteau County.

Winter Storm Watch from late tonight through late Friday night
for Bears Paw Mountains and Southern Blaine-Cascade County below
5000ft-East Glacier Park Region-Eastern Glacier, Western Toole,
and Central Pondera-Eastern Pondera and Eastern Teton-Eastern
Toole and Liberty-Fergus County below 4500ft-Hill County-Judith
Basin County and Judith Gap-Little Belt and Highwood Mountains-
Northern Blaine County-Northern High Plains-Snowy and Judith
Mountains-Southern High Plains-Southern Rocky Mountain Front-
Western and Central Chouteau County.

Winter Weather Advisory until 11 PM MST this evening for Big
Belt, Bridger and Castle Mountains-Cascade County below 5000ft-
Fergus County below 4500ft-Gates of the Mountains-Judith Basin
County and Judith Gap-Little Belt and Highwood Mountains-Meagher
County Valleys-Snowy and Judith Mountains-Southern High Plains-
Southern Rocky Mountain Front-Upper Blackfoot and MacDonald Pass.

High Wind Warning until 3 PM MST this afternoon for Cascade
County below 5000ft-Judith Basin County and Judith Gap-Madison
River Valley.

&&

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