862
FXUS65 KTFX 230523
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1023 PM MST Sat Nov 22 2025

Aviation Section Updated.

.KEY MESSAGES...

- Gusty winds along the Rocky Mountain Front this weekend, with more
  widespread windy conditions Monday.

- Precipitation picks up along the Continental Divide Sunday afternoon,
  with a cold front spreading precipitation farther east Monday.

- Colder temperatures with additional rounds of snow/rain
  throughout the Thanksgiving Week.

&&

.UPDATE...
/Issued 646 PM MST Sat Nov 22 2025/

Slight adjustments were made in the near-term forecast based on
updated model guidance but otherwise the going forecast remains on
track.  -thor

&&

.DISCUSSION...
/Issued 646 PM MST Sat Nov 22 2025/

 - Meteorological Overview:

Mostly dry today, except for a very low end chance for a few
sprinkles underneath the chinook arch across the Rocky Mountain
Front. A 50kt mid level jet along the Rocky Mountain Front
foothills will keep gusty conditions there this afternoon and
Sunday. Westerly flow aloft will advect in moisture Sunday, which
will bring light precipitation to the Continental Divide and the
Rocky Mountain Front. A shortwave trough coming on shore in the
Pacific Northwest will increase precipitation along the
Continental Divide Sunday afternoon and evening as that shortwave
propagates east. The arrival of the cold front late Sunday night
through early Monday morning and the shortwave following behind
will bring better chances for scattered to widespread rain/snow
showers across the region. The arrival of the shortwave aloft will
also bring gusty winds across the region, with the strongest
gusts along the Rocky Mountain Front. Mountain snow and lower
elevation rain/snow continue periodically behind the front
throughout the day Monday, winding down early Tuesday morning.

Northwest flow aloft will bring a few additional rounds of light
mountain snow and lower elevation rain/snow through the
Thanksgiving Week. Temperatures are also expected to cool to near
to below averages by mid week. Next weekend, ensembles hint at
another system bringing in colder temperatures and snow. Though
there are big differences in timing/location of this trough and
how much cold air it brings. It`s hard to pinpoint details now but
it can impact post- Thanksgiving travel.

 - Forecast Confidence & Scenarios:

Winds Monday:

It seems like the mid level jet is not as strong as it has been in
previous runs. Right now, guidance has this jet reaching isolated
45-50kts. This mid level jet arriving during the day Monday will
be good timing for vertical mixing to take place as well with the
cold front passage bringing stronger winds. Therefore, I can`t
rule out an isolated chance for a high wind gust. However,
confidence is not high enough to issue any High Wind Products at
this time, but it`s worth to keep monitoring. Probabilistic
guidance also supports this, giving a 10-30% chance for 58 mph
east of the immediate Rocky Mountain Front foothills.

Snow at the Beginning of the Week:

It still looks on track for the Eastern Glacier Park Region
receiving the bulk of the snow Sunday through Tuesday morning.
Probabilities for 6" are around 70% and a 30% chance for 9" of
snow along Marias Pass. The main uncertainty in snowfall totals
is that marginal temperatures and warm pavements will make snow
struggle to accumulate at first Sunday night through Monday
morning. The heaviest period of snowfall still looks to be Monday
afternoon through early evening, where more moderate snowfall
rates can help stick accumulations to roadways. I have good
confidence for minor to moderate impacts along Marias Pass, so
I`ve issued a Winter Weather Advisory for the Eastern Glacier
Park Zone. Peak winds look to be before the more moderate snow
rates comes in, but winds will be a little gusty throughout the
day. Therefore, there may be some instances of blowing snow and
reduced visibilities.

One area to watch is some recent guidance indicate a band of snow
developing along the northside of that low pressure tracking a bit
farther south along the Hi-line. Impacts will depend on where the
low tracks and the time of day when this band develop. If it does
track a bit farther south but happens in the afternoon, then it`ll
mostly be rain/a mix. If it sticks around later into the night, then
there may be more light accumulations up to of a few inches.
Depending on the low track, Winter Weather Advisories may be
needed for King`s Hill Pass and the Bear`s Paw as well.
Uncertainty in how much QPF falls made me held off on the issuance
for now in those areas for now. -Wilson

&&

.AVIATION...
23/06Z TAF Period

Gusty winds will continue to impact KCTB, KHVR, and KGTF through
the period with some brief periods of LLWS possible at KHVR
through 23/12Z. Winds will start off gusty at KEKS but taper off
by 23/16Z. Otherwise the main concern through the period will be
mid-level BKN to OVC cloudiness across the region after 23/12Z.
Some periods of mountain obscuration are possible especially along
the Northern Rockies where snow showers are expected to develop
after 23/12Z and continue through the rest of the period.  -thor


&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  55  37  45 /   0  10  20  60
CTB  36  50  29  36 /   0  10  20  80
HLN  30  45  32  40 /   0   0  20  60
BZN  24  50  28  44 /   0   0  10  70
WYS  18  43  22  34 /   0   0  10  80
DLN  26  49  29  45 /   0   0   0  30
HVR  33  55  27  39 /   0  10  20  80
LWT  33  56  32  44 /   0  10  10  60

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 11 PM Sunday to 11 PM MST Monday
for East Glacier Park Region.

&&

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