Area Forecast Discussion
Issued by NWS Great Falls, MT

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424
FXUS65 KTFX 241424
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
824 AM MDT Sun Aug 24 2025

.KEY MESSAGES...

 - Temperatures will gradually warm up today through Tuesday, with
   temperatures slightly cooling down Wednesday through Friday.

 - Precipitation chances will return to Southwestern Montana today
   and increase through the middle of this week.

 - Smoky and hazy skies due to wildfires will continue in
   Southwestern Montana for the next few days.

&&

.UPDATE...

No major changes were made to the going forecast. Everything
remains on track for now.  -thor

&&

.DISCUSSION...
/Issued 440 AM MDT Sun Aug 24 2025/

 - Meteorological Overview:

Today there is an upper-level ridge over North-central, Central, and
Southwestern Montana. This will allow temperatures to warm up a few
degrees today. This evening an upper-level shortwave will move
through the upper-level flow. This combined with a slight increase
in monsoonal moisture will allow for very isolated showers and
thunderstorms along the Montana/Idaho border in Southwestern
Montana. On Monday the upper-level ridge remains over North-central,
Central, and Southwestern Montana. This will allow temperatures to
warm up a few more degrees on Monday. Monday evening another upper-
level shortwave will move over Southwestern Montana. This combined
with an increase in monsoonal moisture compared to Sunday will allow
isolated showers and thunderstorms to form a little farther north on
Monday but still be primarily confined to the Montana/Idaho border.
On Sunday and Monday skies will periodically be smoky and hazy due
to smoke from wildfires.

Tuesday through Thursday the upper-level ridge remains over North-
central, Central, and Southwestern Montana. Tuesday through
Thursday each afternoon and evening an upper-level shortwave
moves through the upper-level flow. This will bring showers and
thunderstorms primarily to Southwestern Montana each day. However
on Wednesday and Thursday an isolated shower and/or thunderstorm
could sneak up to Central Montana. Monsoonal moisture will
continue to increase each day in Southwestern Montana peaking on
Thursday. A weak cold front will move through Southwestern,
Central, and North-central Montana during the day on Wednesday
which will cool down temperatures on Wednesday and Thursday across
the area with the coldest temperatures in Southwestern Montana.
On Friday and Saturday the upper-level ridge remains over North-
central, Central, and Southwestern Montana. This will allow
temperatures to warm back up with isolated showers and
thunderstorms across the area.

 - Forecast Confidence & Scenarios:

The biggest area of uncertainty with this forecast period is how
far north showers and thunderstorms will spread on Wednesday and
Thursday. On Tuesday and Wednesday there is a 25 - 50% chance for
thunderstorms in Southwestern Montana with the highest chances along
the Montana/Idaho Border. On Thursday there is a 30 - 45% chance for
thunderstorms across Central and Southwestern Montana. On Tuesday
there is a 20 - 50% chance for a quarter inch of rain or greater
across the southern half of Beaverhead, Madison, and Gallatin
Counties. Wednesday through Thursday there is a 25 - 60% chance for
a half inch of rain or greater across Southwestern Montana. Overall
there is high confidence in the upper-level pattern during this
forecast period. -IG

&&

.AVIATION...
24/12Z TAF Period.

VFR conditions are expected over the CWA through the period. Do
expect some passing mid/high level clouds across the CWA through
from time to time. The main impact will be smoke from wildfires
over Western MT and Idaho. Most of the smoke is aloft and not
reducing visibility at the surface at this time, although some
distant mountain ranges could be obscured at times. Brusda

Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  82  50  86  52 /   0   0   0   0
CTB  80  46  83  49 /   0   0   0   0
HLN  85  53  87  54 /   0   0   0   0
BZN  85  46  86  49 /   0   0   0   0
WYS  82  38  81  43 /   0   0  20  30
DLN  85  48  84  52 /   0   0  10  10
HVR  80  48  84  49 /   0   0   0   0
LWT  77  48  81  48 /   0   0   0   0

&&

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

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