Great Falls, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

762
FXUS65 KTFX 131722
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1122 AM MDT Wed Aug 13 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Hot, dry, and windy conditions are expected today across
   Southwest through North Central Montana.

 - Isolated to widely scattered showers and thunderstorms are
   possible across extreme Southwest Montana near the Idaho border
   and North Central Montana north of the US Hwy 2 corridor from
   this afternoon through Thursday.

 - Brief cool down will occur in wake of a cold front on Thursday
   over the plains of Central and North Central Montana, with
   temperatures moderating back to near normal on Friday.

&&

.UPDATE...
/Issued 812 AM MDT Wed Aug 13 2025/

Showers and isolated thunderstorms across Southwest MT this
morning will continue to exit off to the east over the next few
hours. Isolated showers and thunderstorms remains possible this
afternoon south of the I-90 corridor.

&&

.DISCUSSION...
/Issued 812 AM MDT Wed Aug 13 2025/

 - Meteorological Overview:

Zonal flow through this afternoon will begin to back to the
southwest as a shortwave over Southern British Columbia and the
Pacific Northwest slides east and over the Northern and Canadian
Rockies from this evening through Thursday morning. At the surface a
cold front will being to plunge south along the Canadian Rockies in
Alberta this evening; with this front moving through North Central
Montana by the late evening hours tonight and Central Montana
through the mid-morng hours on Thursday. While this front will
eventually move through Southwest Montana late Thursday
afternoon/evening it will be significantly weaker/modified, with
little to no noticeable temperature changes. Gusty southwest to west
winds will be experienced across all locations prior to the passage
of the aforementioned cold front today through Thursday, with the
strongest winds expected along the Rocky Mountain Front and in the
north-south valleys of Southwest Montana. Strong warm air advection
ahead of the shortwave will help to push temperatures into the upper
80s to mid-90s today, with temperatures ranging from the upper 60s
to upper 70s over the plains of Central and North Central Montana to
the mid-80s to near 90 degrees in the valleys of Central and
Southwest Montana on Thursday. Predominately dry conditions are
expected despite the passage of the cold front and upper level
shortwave; however, isolated to scattered showers and storms can`t
be ruled out southeast of a Dillon to Bozeman line either day or
along and mainly north of the US Hwy 2 corridor during the morning
hours on Thursday.

Near to above normal temperatures will quickly return to the
Northern Rockies by Friday and persisting through next week as
southwesterly flow aloft develops over the Northern Rockies as upper
level ridging builds west from the Northern through Southern High
Plains of the CONUS to the Great Basin. Best opportunity for showers
and thunderstorms looks to occur from Sunday afternoon through
Sunday night as a shortwave lifts northeast within the flow, with
otherwise limited chances for precipitation. - Moldan

 - Forecast Confidence & Scenarios:

Gusty Winds from this morning through Thursday afternoon:

Anomalously (1 to 2.5 standard deviations above normal) strong winds
for mid-Augst, particularly at H700 where wind speeds of 20-40kts
will be common over much of Southwest through North Central Montana,
will overspread the Northern Rockies from the mid-morning hours
today through Thursday afternoon. Mixing, particularly from the late
morning hours through this evening, and then with the passage of a
cold front Wednesday night/Thursday morning will help to translate
these stronger winds to the surface. Latest NBM probabilistic
guidance supports a 80+% chance for wind gusts of 30 mph or greater
for areas west of an Inverness, to Stanford, to White Sulphur
Springs, to Bozeman, to West Yellowstone line through the day today,
with a 40-70% chance for areas east of this line. The probability
for wind gusts in excess of 40 mph through this same timeframe is
generally less than an 50% chance across most areas, with the
exception of the wind prone north-south valleys in Southwest
Montana and along the Rocky Mountain Front where a 60-90% chance
exists. By Thursday the threat for widespread gusty winds will have
pushed south to all but Southwest and portions of Central Montana,
mainly south of the US Hwy 12 corridor, with the north-south
orientated valleys once again having the highest probabilities for
wind gusts in excess of 30 mph and 40 mph at 90+% and 50-60% chances
respectively. - Moldan


&&

.AVIATION...
13/18Z TAF Period

Gusty west winds develop early this afternoon and continue into
early this evening with gusts peaking around 25-35kts at most
terminals late this afternoon. Predominant VFR conditions are
expected at most terminals, though some isolated hi-based showers
and thunderstorms are possible near the KEKS and KWYS terminals
this afternoon with erratic wind gusts and lightning being the
primary concern near these cells. Winds diminish this evening with
a cold front moving south from Alberta shifting winds to the
north across N-central MT through the overnight period and some
potential for lower clouds to move in behind the front at KCTB.
Hoenisch

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

&&

.FIRE WEATHER...

Fire weather concerns will be elevated today with very warm
afternoon temperatures and low afternoon humidity combined with
breezy to windy conditions across much of the area. The most
critical conditions are expected across southwest MT where fuels
are drier. Further north across most of central/north-central MT,
fuels/fire danger are not at critical thresholds following recent
precipitation, but the very warm, dry and windy conditions will
bring an elevated risk for fire spread in areas where fuels may be
locally more receptive. Hoenisch

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  92  56  80  52 /   0  10  10   0
CTB  88  51  69  50 /   0  20  20  10
HLN  94  55  87  53 /  10   0   0   0
BZN  94  50  91  48 /  20   0  10   0
WYS  84  39  82  38 /  30  10  20  20
DLN  90  48  88  46 /  20   0   0   0
HVR  95  56  76  52 /   0  10  20   0
LWT  89  54  77  50 /   0   0  10  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
&&

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