Malmstrom A F B, Montana Weather Forecast Discussion

820
FXUS65 KTFX 012101
AFDTFX
Area Forecast Discussion
National Weather Service Great Falls MT
301 PM MDT Wed Oct 1 2025
.KEY MESSAGES...
- Mild and mostly dry this afternoon through noon on Thursday.
- Temperatures begin to cool down on Friday with the coldest temperatures
   of this fall season expected Saturday night through Monday
   morning.
- Precipitation chances return Thursday afternoon through Friday
   with the risk for flash flooding over burn scars in Southwestern
   Montana.
- Widespread precipitation is expected this weekend with
   mountain snow.
&&
.DISCUSSION...
- Meteorological Overview:
This afternoon through Thursday afternoon there will be southwest
flow aloft ahead of an approaching Pacific upper-level trough. This
will allow above seasonal averages for temperatures this afternoon
and tomorrow with mostly dry weather through noon on Thursday.
Thursday afternoon due to the approaching trough combined with warm
temperatures there will be enough instability for isolated showers
and thunderstorms across North-central, Central, and Southwestern
Montana with the greatest risk of showers and thunderstorms in
Southwestern Montana and along the Rocky Mountain Front. On Friday
the Pacific upper-level trough moves over North-central, Central,
and Southwestern Montana. This will cool down temperatures and bring
another round of showers and thunderstorms to North-central,
Central, and Southwestern Montana. On Friday the greatest potential
for any thunderstorms is in Southwestern Montana. If a
thunderstorm moves over a burn scar there is the risk for flash-
flooding.
On Saturday the upper-level trough remains over North-central,
Central, and Southwestern Montana. A surface cold front will move
south from Canada during the day on Saturday. This will lower snow-
levels across the mountains of North-central, Central, and
Southwestern Montana and bring precipitation (mountain snow and
lower-elevation rain) to the area. On Sunday the upper-level
trough will remain over the area. Sunday morning through Monday
morning due to the cold front there will be the coldest
temperatures of the fall season so far. Precipitation (mountain
snow and lower-elevation rain) will linger across North-central,
Central, and Southwestern Montana on Sunday. On Monday and Tuesday
an upper-level ridge builds back in over the area. This will
allow temperatures to slowly warm up with mostly dry weather
across North-central, Central, and Southwestern Montana on Monday
and Tuesday. -IG
- Forecast Confidence & Scenarios:
There is a 15 - 30% chance for thunder on Thursday along and north
of a line from Monida Pass to Lewistown and south of a Butte to
Helena to Belt line. There is a 15 - 30% chance for thunder on
Friday across Central and Southwestern Montana. On Saturday there is
a 15 - 25% chance for thunder across Southwestern Montana. On Sunday
there is a 25% chance for thunder in the West Yellowstone area.
On Friday there is 20 - 45% chance for a quarter inch of rain or
greater across North-central Montana. On Friday there is a 30 - 60%
chance for a quarter inch of rain or greater across North-central,
Central, and Southwestern Montana. On Friday west of a Helena to
Monida Pass line there is a 35 - 60% chance for a half inch of rain
or greater. Saturday through Sunday across Central and Southwestern
Montana there is 35 - 70% chance for a quarter inch of precipitation
or greater. Saturday through Sunday across North-central Montana
there is a 15 - 40% chance for a quarter inch of precipitation or
greater. Saturday through Sunday in Madison and Gallatin County
there is a 40 - 70% chance for a half inch of rain or greater.
Saturday morning through Monday morning there is a 40 - 75% chance
for 4 inches or greater snowfall across the mountains of Madison and
Gallatin Counties. Saturday morning through Monday morning there is
a greater than a 60% chance for an inch of snow or greater across
the mountains of North-central, Central, and Southwestern
Montana. Sunday morning there is greater than a 50% chance for
temperatures of 32 degrees or less across most of the lower-
elevations of North-central, Central, and Southwestern Montana.
On Monday morning there is a greater than an 80% chance for
temperatures of 32 degrees or less across the lower-elevatons of
North-central, Central, and Southwestern Montana.
-IG
&&
.AVIATION...
01/18Z TAF Period.
Southwesterly flow aloft will maintain variable cloudiness and a few
mostly mountain showers over the duration of the TAF period. VFR
conditions are generally expected, but mountains will be obscured
at times, especially along the Rocky Mountain Front and over the
higher terrain of the southwest. South to southwesterly surface
winds may gust over 30 kts at times over the plains and in the
Madison Valley (KEKS area) through 02/00Z. - RCG
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF  43  73  47  62 /   0  10  50  60
CTB  40  67  42  61 /  10  10  10  20
HLN  44  72  47  62 /   0  20  70  70
BZN  44  74  44  70 /  10  40  40  50
WYS  33  67  35  64 /  10  20  20  50
DLN  42  67  42  66 /  10  40  60  60
HVR  43  74  45  65 /   0   0  20  40
LWT  44  72  45  68 /   0  10  50  40
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls

NWS TFX Office Area Forecast Discussion