140
FXUS65 KTFX 280555
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1055 PM MST Thu Nov 27 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Widespread snowfall will begin this evening and continue
   through Saturday morning with the greatest impacts across
   North-central Montana on Friday.

 - Coldest temperatures of the winter so far will move into the
   area Friday afternoon through Monday morning with Saturday
   through Sunday morning being the coldest.

 - Another system will bring widespread snowfall to the area
   Tuesday through Wednesday.

&&

.UPDATE...
/Issued 809 PM MST Thu Nov 27 2025/
Update forecast is out for this evening. Overrunning light
rain/snow is moving through Central/North Central MT this evening.
Some freezing rain reported just south of Great Falls, while light
rain falling around Helena. Snow falling from about Great Falls
northward. Web cams in the Conrad/Cut Bank area show about 1/2 to
1 inch of snowfall so far this evening. The precipitation is
moving into the Havre/Lewistown areas as of 8 PM.

Overall the storm is on track. No changes to current statements at
this time. The main concern is the NAM model is about 3 hours
slower with the precip arriving in Southwest MT on Friday morning.
This could have more of an impact if the brunt of the snow hits
late morning/early afternoon. Thus the potential for snow squalls
along/south of I-90 from Butte to Bozeman has gone up a bit.

Overall, do expect cold air to move into the CWA from north to
south throughout the day. Wet roadways will freeze over, as this
air mass is very cold. North winds gusting near 40 mph at times
from Cut Bank to Helena will create near whiteout conditions at
times in open areas. By Friday evening, air temperatures will be
around 15 above in Helena, near 10 above in Great Falls, and in
the single digits in the Cut Bank area. Wind chills will make it
feel much colder. These conditions could create impacts for
outdoor events planned for on Friday evening. Even though all
areas might not receive a significant snowfall with this event,
the combination of all the weather conditions will make for a
difficult day to be outside. Brusda

&&

.DISCUSSION...
/Issued 809 PM MST Thu Nov 27 2025/

 - Meteorological Overview:

This afternoon there is an an upper-level trough approaching North-
central, Central, and Southwestern Montana. There is also a warm
front moving north through Central and North-central Montana. This
will override the cold surface air and bring snow to North-central
Montana this afternoon and evening. Tonight into early tomorrow
morning a cold front will move through North-central Montana. This
will bring another round of snow to North-central Montana early
Friday morning through the day on Friday. Early Friday morning
through the day on Friday there will be gusty winds which will lead
to blowing and drifting snow. Friday morning the front will move
through Central Montana and bring snowfall to that area. The front
progression will slow down as it reaches Southwestern Montana, but
it will still bring a light round of snow to Southwestern Montana.
Friday afternoon along and south of I-90 combined with the
frontal passage there is the potential for snow squalls.

On Saturday the upper-level trough will remain over North-central,
Central, and Southwestern Montana. Snow will linger through early
Saturday morning with cold temperatures across North-central,
Central, and Southwestern Montana. On Sunday the upper-level trough
remains over North-central, Central, and Southwestern Montana. This
will bring another day of cold temperatures to the area with the
coldest temperatures of the year expected Saturday through Sunday
morning. On Monday an upper-level ridge builds in over North-
central, Central, and Southwestern Montana. This will allow
temperatures to warm up with mostly dry weather. On Tuesday and
Wednesday an upper-level trough will move over the area and bring
another round of snow to North-central, Central, and Southwestern
Montana. IG

 - Forecast Confidence & Scenarios:

On Friday there is greater than an 80% chance for wind gusts of 40
mph or greater across the Rocky Mountain Front and plains west of I-
15. On Friday across much of the rest of North-central, Central, and
Southwestern Montana there is greater than a 60% chance for wind
gusts of 30 mph or greater. Across much of North-central Montana
there is greater than a 50% chance for 6 inches of snowfall or
greater from tonight through early Saturday morning. This combined
with the wind gusts led to Winter Storm Warnings being issued across
all of North-central Montana. Across the Helena, Gallatin, and
Madison River Valley there is a 30 - 60% chance for two inches of
snow or greater tonight through early Saturday morning. As a result
Winter Weather Advisories are in effect for those areas. For details
see the TFX WATCHES/WARNINGS/ADVISORIES section below.

With the passage of the cold front combined with a little
instability Friday afternoon along and south of I-90 there is
medium confidence in there being snow squalls Friday afternoon.
Saturday morning across the Hi-Line, Golden Triangle Region
(triangular area from Cut Bank to Havre to Great Falls), and
Gallatin valley there is greater than a 60% chance for subzero
temperatures. Sunday morning there is greater than a 50% chance
for subzero temperatures across all of North-central Montana.
Sunday morning across the Milk River Valley there is greater than
a 50% chance for temperatures of 10 below zero or lower. Monday
morning across the Milk River Valley there is greater than a 60%
chance for subzero lows. On Saturday there is greater than a 50%
chance for highs of 15 degrees or lower across much of North-
central Montana. On Sunday there is greater than a 50% chance for
highs or 15 degrees or colder across North-central Montana east
of I-15. IG

&&

.AVIATION...
28/06Z TAF Period

The cold front will continue to make its way south across the
region, shifting winds to the north and bringing periods of
enhanced snowfall. Periods of blowing snow and even whiteout
conditions are possible at KCTB, KHVR, and KGTF. Snow and lower
CIGs will spread into southwest Montana by 28/15Z. Mountain
obscuration across north-central, central, and southwest Montana
will remain a concern through the period. -thor

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  18  18  -2  14 /  80  90  40   0
CTB  11  14 -12  10 / 100  90  20   0
HLN  19  22   3  21 /  70 100  30   0
BZN  24  28   0  20 /  40  90  40   0
WYS  18  32  -6  21 /  10  80  60   0
DLN  28  39   4  24 /  10  70  20   0
HVR  13  20 -10   8 /  90  90  70   0
LWT  15  20  -2  17 /  90  90  70  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 11 PM MST Friday for Cascade County
below 5000ft-Eastern Pondera and Eastern Teton-Eastern Toole and
Liberty-Southern High Plains-Southern Rocky Mountain Front-
Western and Central Chouteau County.

Winter Storm Warning until 5 AM MST Saturday for Bears Paw
Mountains and Southern Blaine-Fergus County below 4500ft-Hill
County-Northern Blaine County.

Winter Weather Advisory until 5 AM MST Saturday for Big Belt,
Bridger and Castle Mountains-Elkhorn and Boulder Mountains-
Gallatin Valley-Gates of the Mountains-Helena Valley-Judith
Basin County and Judith Gap-Little Belt and Highwood Mountains-
Madison River Valley-Snowy and Judith Mountains.

Winter Storm Warning until 5 PM MST Friday for East Glacier Park
Region-Eastern Glacier, Western Toole, and Central Pondera-
Northern High Plains.

Winter Weather Advisory until 5 PM MST Friday for Upper
Blackfoot and MacDonald Pass.

&&

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