404
FXUS65 KTFX 202102
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
202 PM MST Thu Nov 20 2025

.KEY MESSAGES...

 - Lingering low stratus clouds and patchy fog this afternoon
   across Southwest MT.

 - Breezy to windy conditions along the Rocky Mountain Front this
   weekend and early next week.

 - Mostly dry through the end of the week, with colder
   temperatures and light snow during Thanksgiving week.

&&

.DISCUSSION...

 - Meteorological Overview:

Current satellite shows low stratus and patchy fog lingering
around early this afternoon across Southwest MT. Recent trends
this past hours show this starting to burn off. If low clouds
don`t burn off before sunset, then they might linger throughout
the nighttime. Everywhere else, clear skies and dry conditions
remain today. There is a slight chance for fog redevelopment
overnight. However, there will be a slight pick up in southwest
winds overnight. This can limit the fog development and duration.

Westerly flow aloft will keep the mild temperatures and mostly
dry conditions through the weekend. The only exception is light
snow along the Northern Continental Divide. A tighter pressure
gradient sets up along the Rocky Mountain Front Friday, which
will bring breezy to windy conditions along the Rocky Mountain
Front. Saturday and Sunday, a few waves of stronger mid level
winds will mix down breezy winds along the Rocky Mountain Front.

An approaching shortwave trough Monday and cold front will bring
the next chances for more widespread light precipitation.
Increasing 700mb winds aloft combined with the cold front passage
will bring gusty winds. After this system moves through, northwest
flow aloft sets up through Thanksgiving. This will continue to
usher in colder air, and additional rounds of light snow to the
region.

 - Forecast Confidence & Scenarios:

For winds tomorrow, although the pressure gradient being around
6-10mb suggests windy condtions along the front, a lack of mid
level winds will make it a bit more difficult for winds to reach
high wind criteria. Though, we could see some 60-65 mph wind
gusts along the immediate foothills.

Strong winds Monday are still a bit of a toss up with models being
more wishy washy with how strong the mid level winds move in.
There`s a 40-60% chance for 55 mph winds along the Rocky Mountain
Front, and a 30-50% chance for 45 mph winds across the North-
Central plains. Timing of the front and the strength of the mid
level winds will be important to monitor for higher winds.
Depending on the timing of the winds, forecast soundings do show
mountain wave potential Monday morning as well. Will continue to
monitor in the coming days to see if any high wind products are
needed. I would like for more model consistency before jumping on
a solution.

Snow Next Week:

So far, the region that will be most impacted by snow will be the
Rocky Mountain Front Monday/Tuesday. There`s a 40% chance for 6"
of snow along Marias Pass. Another area to monitor during this
time frame will be areas close to the Canadian border. Current
model guidance shows a band of at least a few inches of snow just
north of the Montana/Canadian border Monday through Tuesday
morning. Any southern trends will bring this band down to the Hi-
line.

After that, a few more rounds of light snow is forecasted through
the Thanksgiving time period. Though, snowfall amounts look
nothing major through the holiday (only a 30% chance for 4" of
snow in the mountains Wednesday-Thursday).-Wilson

&&

.AVIATION...
20/18Z TAF Period

The initial concern this TAF period will be for lingering low clouds
and patchy fog across Southwest Montana valleys. Gradual clearing is
ongoing, and is forecast to continue into the early afternoon.

Looking toward tonight, another round of fog is not out of the
question, but is much lower probability. Hence, any mention of fog
has been withheld for Friday morning at this time. Looking toward
late morning Friday, breezy surface winds will be on the increase
over the plains. -AM

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  32  52  36  54 /   0   0   0   0
CTB  29  48  33  50 /   0   0   0   0
HLN  28  49  29  51 /   0   0   0   0
BZN  24  50  24  51 /   0   0   0   0
WYS  18  44  21  41 /   0   0   0  10
DLN  24  48  24  48 /   0   0   0   0
HVR  25  51  29  53 /   0   0   0   0
LWT  29  54  30  55 /   0   0   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

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