102
FXUS65 KTFX 110330
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
830 PM MST Wed Dec 10 2025

.KEY MESSAGES...

 - Strong winds continue through this evening along the
   Continental Divide, and the Madison River Valley and US Hwy 87
   corridor through Thursday.

 - An Arctic front will surge south across the plains on Thursday,
   bringing falling temperatures and accumulating snow.

 - Heavier snow remains possible on Friday and into Saturday
   morning over portions of Central and North Central Montana, but
   the exact placement of this heavy snow continue to fluctuate.

&&

.UPDATE...

No major changes to speak of with this evening`s update, though I
did allow the High Wind Warnings for the plains adjacent to the
Rocky Mountain Front and around MacDonald Pass to expire. Of note,
a few high resolution models have started to hint at some higher
snow totals in Judith Basin County tomorrow, but I`ll hold off on
adjusting snowfall forecasts for now as I don`t have enough
confidence to do so at this time. Ludwig

&&

.DISCUSSION...
/Issued 448 PM MST Wed Dec 10 2025/

 - Meteorological Overview:

An active pattern will continue across the Northern Rockies through
the end of the work week thanks to an anomalous moisture streaming
eastward from the Pacific Northwest within strong mid-level flow.
This strong mid-level flow will continue to bring high winds to
portions of the valleys and plains of Central and Southwest Montana,
especially those locations near the northern and eastern foothills
of terrain and near terrain gaps. Additionally, an Arctic front will
surge south and across North Central and portions of Central Montana
and undercut the Pacific moisture. Lift associated with this front
will help to support a band of snow advancing south during the day
on Thursday, with a broader area of snow developing on Friday as a
mid-level warm front lifts to the northeast over the Arctic airmass.
Above normal temperatures across all locations through Thursday
morning will fall to below normal in wake of the Arctic front and
remain so through the day on Friday, with the exception of Southwest
and portions of Central Montana were above normal temperatures will
continue. - Moldan

 - Forecast Confidence & Scenarios:

High Winds through this Evening...

The High Wind Warning remains in place for the Northern and Southern
High Plains adjacent to the Rocky Mountain Front, Eastern
Glacier/Western Toole, and Upper Blackfoot and MacDonald Pass
through the early evening hours tonight. Wind gusts across these
areas have been gusting anywhere from 55 mph to near 85 mph due to
the combination of a strong pressure gradient and/or cross barrier
flow and mountain wave activity. It is possible that these warnings
may need to be extended into the day on Thursday, most notably for
the Northern and Southern High Plains adjacent to the Rocky Mountain
Front, given continued mid-level flow of 60-80kts and the presence
of a moderately strong pressure gradient; however, with ridgetop
stability weakening during the overnight hours and a less favorable
environment for mountain wave activity there was enough doubt with
this forecast issuance to hold off on extending the High Wind
Warning for now.

High Winds through Thursday...

The High Wind Warnings for Judith Basin County and Judith Gap, and
Madison River Valley remain in effect through the afternoon hours on
Thursday. High winds will continue across these areas due to the
presence of a strong pressure gradient and terrain funneling.

Arctic Front and Accumulating Snow on Thursday...

Confidence is high in an Arctic front advancing south across the
plains of Central and North Central Montana during the morning to
early afternoon hours on Thursday. At this time most guidance
indicates that the front will initially sag south into portions of
North Central Montana by as early as this (Wednesday) evening before
briefly retreating north prior to 12z on Thursday. Light snow is
likely to accompany this front as it wavers over the plains,
especially across northern portions of Hill and Blaine Counties and
the Easter Glacier Park Region. A strong surge of pressure rises
associated with surface high pressure building south along the
Canadian Rockies will then kick the Arctic front back to the south
and through Cut Bank and Havre between 12-15z (Thursday) and Great
Falls and Lewistown between 15-18z (Thursday). As the Arctic front
begins to interact with the terrain of Central Montana it will begin
to slow and eventually stall, generally along and north of the US
Hwy 12 corridor. A quick 1 to 3" of snow will be possible across
most plains locations outside of the Cut Bank Area and I-15 corridor
north of Great Falls with the passage of the front, with 2 to 4
inches in the Island Ranges and Rocky Mountain Front. In addition to
the threat for accumulating snow, rapidly falling temperatures
associated  with the front will allow for any wet road surfaces to
rapidly freeze. While snowfall amounts are overall on the lighter
side, especially given the snowy pattern that we have been in as of
late, the threat for a flash freeze was the tipping point to issue a
Winter Weather Advisory for any location with 1" or more of
forecasted snow. - Moldan


Winter Storm Watch Friday and Friday night...

The main concern will be how far south the cold front goes and how
much lift do we get on the cold side on Friday to create the
potential for heavy snow over North Central MT. Where the cold front
stalls on Friday will greatly determine where the heavy snow sets up
on Friday. Should the front stall a bit further north, the area of
heavy snow will likely shift northward a bit into southern Canada.
Should the front make it all the way south to I-90, then it is
likely that much of North Central MT could get some heavy snow on
Friday. Overall, the forecast models continue to show the potential
for about a 5 to 12 inch snowfall in the band of heavy snow that
sets up on Friday.

Additionally, there is the potential for some cold weather advisory
statements Friday into Saturday over the northern portions of North
Central MT. Brusda

&&

.AVIATION...
10/18Z TAF Period

An active TAF period is forecast across much of the region. Initial
concerns are for gusty surface winds over parts of the plains
through the overnight, with the potential for LLWS across areas
where surface winds remain/trend light and variable. An initial
weaker front ahead of the main Canadian cold front will result in
a few wind shifts this evening and overnight across the Hi-Line.
Widespread mountain wave turbulence will continue into Thursday.

A mix of rain and snow continues across northeastern portions of
the region this evening and tonight ahead of a stronger cold front
during the day Thursday. This precipitation trends further south
through the day, becoming all snow behind the front which moves
south across the plains during the morning and early afternoon.
Current thinking is that the cold air behind the front will remain
over the plains, hence keeping the precipitation type as rain
over most valleys in Central and Southwest Montana. Mountains will
become increasingly obscured through the TAF period. -AM

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  50  52   2  15 /  20  80  70  80
CTB  36  44  -8   9 /  60  60  60  70
HLN  51  52  24  39 /  20  70  80  60
BZN  42  53  40  47 /  10  60  80  50
WYS  32  38  31  39 /  20  40  70  40
DLN  44  52  47  52 /   0  10  20  10
HVR  28  38  -8   4 /  90  80  60  80
LWT  42  49  15  18 /  60  90  90 100

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from midnight tonight to 3 PM MST
Thursday for Bears Paw Mountains and Southern Blaine-East
Glacier Park Region-Hill County-Northern Blaine County-Western
and Central Chouteau County.

Winter Storm Watch from late Thursday night 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 from 9 AM to 11 PM MST Thursday 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 Thursday for Judith Basin
County and Judith Gap-Madison River Valley.

&&

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