209
FXUS65 KTFX 191537
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
837 AM MST Wed Nov 19 2025

.KEY MESSAGES...

- Scattered areas of light rain and snow continue through this
  afternoon, mostly over southwest Montana and along the
  Continental Divide.

- An active jet stream will bring breezy to windy conditions and
  periods of mountain snow this weekend.

- Colder temperatures and periods of light snow are expected
  heading into Thanksgiving.

&&

.UPDATE...

A mix of rain and snow showers continues this morning, mainly
across portions of Southwest and Central Montana. This will
continue through the day today as a weak system aloft continues to
progress across the Northern Rockies. Aside from localized
reduction in visibility from precipitation and low clouds near
pass level, impacts are forecast to be quite low today.

Areas that end up seeing precipitation today that proceed to clear
out tonight will have increased probability for fog formation for
Thursday morning. Southwest Montana valleys are most favored for
the fog.

The forecast was tweaked slightly to account for latest trends and
guidance. No significant changes were needed. -AM

&&

.DISCUSSION...
/Issued 454 AM MST Wed Nov 19 2025/

 - Meteorological Overview:

Meteorological Overview:

Patchy fog over the Milk River Valley area is slowly dissipating,
but low stratus looks to stick around for much of the morning. A
weak Pacific trough passes through the Northern Rockies today and
will bring scattered areas of light rain and snow through this
afternoon. Most of this activity will be focused over
central/southwest MT and along the Continental Divide. H700
temperatures fall to the -5 to -10C range this morning, lowest
over north-central MT. This should lower snow levels down to the
plains and valleys, but accumulating snow should be minimal with
negligible precipitation amounts. Todays high temperatures will
cool closer to average in response to the frontal passage.

Weak ridging aloft will bring dry and mild conditions for the
second half of the work week while the northern jet stream stays
in Canada and a closed low slides down the California coast. The
upper level jet sags southward into the Northern Rockies this
weekend and brings periods breezy to windy conditions and some
mountain snow. A northwesterly flow aloft develops and sends a
series of colder troughs through the state heading into the
Thanksgiving holiday. This looks to bring a period of strong,
gusty winds followed by occasional mostly light snow and the
coldest temperatures of the season so far. -RCG

 - Forecast Confidence & Scenarios:

Forecast Confidence & Scenarios:

Scattered areas of light rain and snow today...

Colder west to northwesterly flow should lower snow levels to the
valleys and plains, at least briefly. Accumulations, if any, will
be minimal with probabilities for one inch of snow or more around
20% over the higher terrain of central and southwest MT, dropping
to near zero for other areas.

Increasing winds and light mountain snow this weekend..

A tightening surface pressure gradient will bring an initial wave
of windy conditions to the Rocky Mountain Front Friday into
Saturday. Probabilities for 55 mph+ gusts increase to around 80%
over the eastern foothills of the Rocky Mountain Front eastward to
the Browning area. Despite a tightening surface pressure
gradient, H700 winds will mostly be less than 50 kts and will have
a northwesterly trajectory. This situation will continue to be
monitored over the next day or so for increased winds due to
mountain wave activity. Winds will also be on the increase in
other areas throughout the weekend with many central and north-
central locations seeing gusts in the 30 to 50 mph range. Mountain
snow looks to be on the lighter side and mostly confined to the
higher terrain of the Rocky Mountain Front.

Colder temperatures and some snow heading into Thanksgiving

Ensembles are still highlighting a strong trough and attendant
cold front to surge through the Northern Rockies sometime Monday
into Tuesday. The dynamics look supportive for a period of
widespread strong, gusty winds and locally intense snow showers.
The NBM probabilistic guidance hasn`t really caught on to this
with meager chances for 55 mph gusts less than 50% for nearly all
locations, but the ECMWF Extreme Forecast Index and Shift of Tails
is starting to catch onto the stronger winds. The timing of the
front will play a significant role in whether the strongest 60 to
70 kt H700 winds transfer to the surface. This front will usher in
a more active and colder pattern, though recent ensembles have
decreased the amplitude of the troughs passing through the
Northern Rockies. Overall, there`s an expectation for the coldest
temperatures of the season heading into Thanksgiving. - RCG

&&

.AVIATION...
19/12Z TAF Period

A passing trough will maintain considerable cloudiness with
scattered areas of light rain and snow for the first half of the
TAF period. While precipitation will mostly be concentrated over
central and southwest MT, the plains terminals will be most
susceptible to MVFR cloudiness through 19/20Z. Most of the
precipitation will end after 20/00Z, but scattered to broken low
VFR clouds will remain over the southwest and there may be some
patchy fog over some river valleys in central/north-central MT
heading into the overnight hours. - RCG

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  26  53  33 /  20   0   0   0
CTB  45  22  50  30 /  10   0   0   0
HLN  43  27  49  28 /  40  10   0   0
BZN  48  24  50  24 /  30  20   0   0
WYS  43  24  45  18 /  30  20  10   0
DLN  47  27  47  24 /  20  20   0   0
HVR  44  19  46  26 /  10   0   0   0
LWT  42  24  53  29 /  10  10   0   0

&&

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

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