659
FXUS65 KTFX 100514
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1114 PM MDT Thu Oct 9 2025

Aviation Section Updated.

.KEY MESSAGES...

 - It will be dry and mild through Friday.

 - It will be windy on Saturday and Sunday with showers and
   thunderstorms primarily in Southwestern Montana.

 - Saturday night through early next week it will be significantly
   colder with mountain snow and lower-elevation snow/rain.

&&

.UPDATE...
/Issued 856 PM MDT Thu Oct 9 2025/

Only a few minor tweaks to temperatures to account for ongoing
trends this evening. Ludwig

&&

.DISCUSSION...
/Issued 856 PM MDT Thu Oct 9 2025/

 - Meteorological Overview:

This afternoon there is an upper level ridge over North Central,
Central, and Southwestern Montana which will bring dry and mild
weather to the area today. On Friday the upper level ridge remains
over North Central, Central, and Southwestern Montana with an upper
level trough approaching Montana. Due to the upper level trough
approaching the area there will be warm air advection aloft. This
will lead to well above seasonal averages for temperatures on
Friday. Additionally due to an increasing pressure gradient and
strong upper level flow it will be windy in Southwestern Montana on
Friday. On Saturday the upper level trough begins to move over North
Central, Central, and Southwestern Montana. Saturday
afternoon/evening a pacific cold front will move through the area.
Ahead of this front due to warm temperatures and the upper level
trough there will be enough instability and shear to produce
isolated thunderstorms in Central and Southwestern Montana. Isolated
thunderstorms will produce heavy rain. Also associated with the
front there will be scattered showers across North Central, Central,
and Southwestern Montana. Saturday night through Sunday morning the
cold front will lower snow levels and bring mountain snow and lower
elevation rain/snow. Due to the cold front, and strong upper level
winds it will be windy on Saturday.

On Sunday the upper level trough remains over North Central,
Central, and Southwestern Montana in the morning before an upper
level ridge begins to build in Sunday afternoon and evening. This
will allow precipitation to linger across the area Sunday morning
with precipitation exiting Sunday afternoon. Due to the cold front
that moved through on Saturday it will be significantly cooler on
Sunday across North Central, Central, and Southwestern Montana. On
Sunday due to strong upper-level winds it will be windy. On Monday
morning the upper level ridge remains over the area before an upper
level trough moves over North Central, Central, and Southwestern
Montana. The upper level trough will remain over the area through at
least Wednesday which will bring rounds of precipitation to the area
from Monday afternoon through Wednesday with well below seasonal
average temperatures. IG

 - Forecast Confidence & Scenarios:

There is a 40 to 80% chance wind for gusts of 40 mph or greater on
Friday across Madison County and southeastern Beaverhead County.
There is a 30 to 60% chance for wind gusts of 45 mph or greater on
Saturday along the Rocky Mountain Front and adjacent plains. There
is a 15 to 40% chance for wind gusts of 40 mph or greater across
most of the rest of North Central, Central, and Southwestern
Montana. There is a 20 to 60% chance for wind gusts of 40 mph or
greater on Sunday across North Central, Central, and Southwestern
Montana with the highest probabilities along the Hi-Line and in
Fergus County. On Sunday there is a 25 to 50% chance for wind gusts
of 45 mph or greater in Fergus and Blaine Counties.

There is a 30% chance for thunder on Saturday south of the US
Highway 87/Montana Highway 200 Corridor between Great Falls and
Lewistown. Saturday morning through Monday morning there is a 15 to
40% chance for an inch of precipitation or more across most of North
Central, Central, and Southwestern Montana.

Saturday morning to Monday morning there is greater than a 60%
chance for 8 inches of snow or greater across the Rocky Mountain
Front, Little Belts, and Madison and Gallatin Mountains. As a result
Winter Storm Watches were issued for those locations from Saturday
evening through Monday morning. Saturday morning to Monday morning
there is a 20 to 50% chance for an inch of snow or greater across
the lower-elevations of North-central Montana. Saturday morning to
Monday morning there is a 15 to 40% chance for two inches of snow or
greater across the lower-elevations of North-central Montana. IG

&&

.AVIATION...
10/06Z TAF Period

The main concern this TAF period with be a wave of showers lifting
north across Southwest MT early this morning. Showers are expected
to keep conditions mostly VFR. However, I can`t rule out a
heavier shower bringing brief MVFR visibilities. There`s a little
uncertainty in how far north this wave of precipitation goes, so
I let out the mention at the KHLN, KGTF, and KLWT TAFs for now.
Breezy south/southeast winds pick up in Southwest MT Friday
afternoon. -Wilson

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  38  75  47  68 /   0  10  10  60
CTB  33  69  43  64 /   0   0  10  30
HLN  40  77  48  64 /   0  10  20  70
BZN  39  75  46  67 /   0  20  10  70
WYS  34  65  40  57 /  20  40  40  80
DLN  39  72  44  62 /  10  10  30  70
HVR  38  73  44  70 /   0   0   0  30
LWT  40  76  49  70 /   0  10   0  60

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Saturday evening through Monday morning
for East Glacier Park Region-Southern Rocky Mountain Front.

Winter Storm Watch from Saturday evening through late Sunday
night for Gallatin and Madison County Mountains and Centennial
Mountains-Little Belt and Highwood Mountains.

&&

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