615
FXUS65 KTFX 010544
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1044 PM MST Sun Nov 30 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Locally windy conditions Monday may create some drifting and
   blowing snow.

 - Temperatures moderate back to near seasonal averages later this
   week.

 - Periods of snowfall Monday night through Tuesday and again this
   upcoming weekend.

&&

.UPDATE...
/Issued 830 PM MST Sun Nov 30 2025/
Updated forecast is out. Main adjustment this evening was to lower
temperatures towards current trends in the cold spot. That being
said, warmer air is slowly moving in from the west, as westerly
winds increase. There is about a 40 degree change in temperature
this evening from the Great Falls area being near 20 above to
areas north of Havre that are near 20 below this evening. Thus the
cold advisory will continue for Hill/Blaine counties. The warm
air will continue to move in, but it will take time, and some
areas will not mix out until Monday.

Otherwise, expect periods of snow to start tomorrow and then
continue through the rest of the week. Tue/Wed looks to be the day
when the snowfall is the most widespread. The current winter
weather advisory for snow looks good, but additional areas might
be added later this week. Brusda

&&

.DISCUSSION...
/Issued 830 PM MST Sun Nov 30 2025/

 - Meteorological Overview:

An amplified upper level pattern is in place with a deep upper low
centered near Hudson Bay and ridging just off of the west coast
and north to northwest flow aloft over the Northern Rockies.
Meanwhile, the next shortwave disturbance upstream moves over the
ridge through he Gulf of AK and drops south through the Pacific
NW and Northern Rockies Monday night through Tuesday

A shallow cold airmass remains firmly in place across the plains
still this afternoon, but will erode from the west and southwest
tonight as surface high pressure over the Dakotas moves off to the
east and lee-side troughing develops to the east of the Rockies.
This sets up windy conditions across much of north-central MT by
Monday afternoon as northwest flow aloft increases ahead of the
next wave.

Snow develops along northern portions of the Continental divide
(Glacier NP area) early Monday evening under warm advection ahead of
the incoming wave. Areas of snow or snow showers become more
widespread across the rest of the forecast area Wednesday as the
wave moves across the area and lower level flow turns more
northwesterly as surface high pressure rebuilds across AB.

Mainly dry weather with seasonably cool temperatures is expected
Wednesday and Thursday before the next series of Pacific weather
disturbances arrives beginning Friday. There is considerable
spread in details involving the southward extent cold air centered
north of the border and the timing/trajectory of these
disturbances, but potential exists for several rounds of
precipitation as these systems move through next weekend. Hoenisch

 - Forecast Confidence & Scenarios:

While strong winds are not expected Monday, 35-40 mph wind gusts
will be widespread across portions of north-central MT adjacent to
the central MT mountains with higher gusts along the east slopes
of the Rocky Mtn Front. A settled snow-pack will likely mitigate
much of the blowing snow potential but snow drifting across
roadways could still affect visibility in open exposed areas.

Winter weather advisories have been issued for the Monday night
through Tuesday period for the Glacier NP/Rocky Mountain Front areas
and central MT/Gallatin and Madison county mountain ranges.
Marias Pass is likely to see a period of steadier snow with
accumulation of 2-3 inches Monday night through Tuesday morning,
while areas to the east see northwesterly upslope enhanced snow
with a 30-50% probability for amounts in excess of 4 inches across
the Little/Big Belt and Bridger ranges. Hoenisch

&&

.AVIATION...
01/06Z TAF Period

Main concerns for Monday morning is fog developing in KHLN. Fog
should prevail IFR/MVFR but there`s a slight chance of
visibilities dropping to IFR at times. West/southwest winds pick
up later today across the North-Central MT plains. A wave of light
snow arrives Monday evening. This can bring MVFR to IFR
conditions. -Wilson

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF   8  34  28  35 /   0   0  40  80
CTB   5  31  23  33 /   0   0  30  60
HLN   9  34  25  35 /   0  10  40  80
BZN   2  31  21  35 /   0   0  40  70
WYS   0  25  14  28 /   0  10  60  90
DLN  11  36  23  37 /   0   0  20  40
HVR -19  31  20  35 /   0   0  50  60
LWT   3  35  23  33 /   0   0  30  70

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 5 PM Monday to 11 PM MST Tuesday
for East Glacier Park Region-Southern Rocky Mountain Front.

Cold Weather Advisory until 10 AM MST Monday for Hill County-
Northern Blaine County.

Winter Weather Advisory from 11 PM Monday to 5 AM MST Wednesday
for Big Belt, Bridger and Castle Mountains-Gallatin and Madison
County Mountains and Centennial Mountains-Little Belt and
Highwood Mountains-Snowy and Judith Mountains.

&&

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