219
FXUS65 KTFX 292321
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
521 PM MDT Wed Jul 29 2026

Aviation Section Updated.

.KEY MESSAGES...

 - Wildfire smoke continues to bring hazy skies and air quality
   degradation through the week.

 - Hot temperatures persist through the week, with Saturday being
   the hottest day.

 - Afternoon showers and thunderstorms are possible across
   Southwest and portions of Central Montana today and Thursday.

 - Gusty winds Saturday and Sunday with the strongest winds along
   the Rocky Mountain Front will create increased fire weather
   concerns.

&&

.DISCUSSION...
/Issued 1126 AM MDT Wed Jul 29 2026/

 - Meteorological Overview:

The upper-level ridge holds in place with hot temperatures
expected through Saturday. Lingering monsoonal moisture riding
along the ridge will be just enough to have a daily chance for
afternoon showers and thunderstorms today and tomorrow. Wildfire
smoke from the PacNW will continue to funnel into the region
producing hazy skies and, at times, some degradation in air
quality across the region.

Towards the weekend the ridge breaks down as a strong trough moves
into the region. This will bring a short but significant cool down
to the region Sunday through Tuesday but will also work to bring
strong winds that will last Saturday evening into Sunday evening.
This combination of hot, dry, and windy conditions will lead to
increased fire weather concerns. -thor


 - Forecast Confidence & Scenarios:

Thunderstorms Today:

Scattered thunderstorms are expected Wednesday and Thursday
afternoon across Southwest and portions of Central Montana. While
severe weather is generally not expected there is still a concern
for frequent lightning and strong, gusty winds.


Heat This Weekend:

There is good confidence in impactful heat settling in Saturday.
The European Model Extreme Forecast Index shows a 0.7 to 0.95 east
of the Continental Divide Saturday, meaning it will be unusually
hot for this time of year. There remains some model and run to run
inconsistency with how hot it will get. Another big question mark
is the wildfire smoke and if an increase fire weather behavior
across the Pacific Northwest will produce more smoke and dampen
the high temperatures. Regardless, there remains good confidence
in impactful heat Saturday, especially across North-central MT.


Winds This Weekend:

Models still hint at the increasing potential for gusty to strong
winds develop along the Rocky Mountain Front and North-Central MT
late Saturday into Sunday. Models have been consistently showing
a 50-70kt 700mb jet developing along the Rocky Mountain Front and
North-Central MT plains late Saturday night into mid Sunday
morning. The timing of this jet is not the most ideal for high
winds, but good ridgetop stability suggests mountain wave activity
will be possible. Another concern is impact on recreation along
the Rocky Mountain Front/back country due to falling trees. Right
now, there`s a 40-60% chance for 60 mph winds along the immediate
Northern Rocky Mountain Front Foothills. One important
consideration for this weekend will be the wind climatology for
the region with may locations along the RMF potentially exceeding
the 90th percentile for this time of the year. While the
lingering discrepancies in the models make things too uncertain to
issue a high wind watch at this time, it is something that will be
considered with future forecasts as more model data becomes
available.

Additional concerns for the weekend are related to elevated to
critical fire weather conditions Sunday afternoon through Sunday
evening (see the FIRE WEATHER section for more detail).
-Wilson/thor

&&

.AVIATION...
30/00Z TAF Period

VFR conditions will prevail across all terminals during this TAF
Period outside of during any thunderstorms. For the first two hours
of this TAF Period thunderstorms will affect the KEKS and KBZN
terminals. For the first 6 hours of this TAF period there is a
30% chance for thunderstorms at the KWYS terminal. At the end of
this TAF Period there is a 20% chance for thunderstorms at the
KLWT terminal. All thunderstorms will produce heavy rainfall,
small hail, frequent lightning, and gusty, erratic winds. During
any thunderstorms there will be a brief period of mountain
obscuration. Across most of the TAF sites smoke from wildfires
will reduce slantwise visibility. -IG

For KGTF: Light winds are expected through the period, making the
probability for any cross winds low. Main concern will be distant
visibility obscuring mountains/landing operations. Brusda

&&

.FIRE WEATHER...

Elevated to critical fire weather is expected Saturday afternoon
through Sunday evening across North-Central, Central, and
Southwest Montana. On Saturday, hot temperatures in the upper 90s
to mid 100s will combine with minimum RH values as low as 8% and
gusts up to 50 mph with stronger gusts expected along the Rocky
Mountain Front to create the potential for critical fire weather
conditions. Sunday will be cooler but low RH values and strong
winds are still expected which will still pose a significant
concern not only for ongoing fires but any potential new starts
that occur. Given all this, a Fire Weather Watch has been issued
Saturday afternoon through Sunday. -thor

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  58  95  59  97 /  10  10  30   0
CTB  53  90  54  92 /   0  10  10   0
HLN  58  93  57  94 /  10  10  30   0
BZN  54  93  55  94 /  30  10  20   0
WYS  44  84  45  87 /  40  10  10   0
DLN  52  88  53  89 /  30  20  20   0
HVR  59  97  58  98 /  10  10  20   0
LWT  57  90  57  92 /  20  30  20   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Saturday afternoon through Sunday
evening for Central and Eastern Lewis and Clark National Forest
Areas-Chouteau and Fergus Counties-Eastern
Glacier/Toole/Central/Eastern Pondera/Liberty-Helena and
Townsend Ranger Districts of the Helena National Forest-Hill and
Blaine Counties-Lewis and Clark National Forest Rocky Mountain
District-Rocky Mountain Front-Lincoln Ranger District of the
Helena National Forest.

&&

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