Red Flag Warning 4, NWS Great Falls, MT

Area Forecast Discussion
National Weather Service Great Falls MT
412 AM MDT Fri Jul 31 2026

Aviation Section Updated.

.KEY MESSAGES...

- Hot temperatures through Saturday before a cooldown Sunday through
  the first half of next week.

- Hot, dry, and windy conditions Saturday and Sunday bring
  critical weather conditions across the region.

- Wildfire smoke continues to impact the region through the end of
  the week.

- Dry conditions settle in into next week.

&&

.DISCUSSION...
/Issued 1145 PM MDT Thu Jul 30 2026/

 - Meteorological Overview:

The upper-level ridge pattern continues Friday which will bring
another day of hot temperatures to the region. Drier PWATs and
little forcing Friday will keep most of the region dry, but I can't
rule out a few showers and thunderstorms in Southwest MT during
the afternoon. Temperatures peak on Saturday as the ridge
breakdowns and southwest flow increases. Lower elevations are
forecasted to reach into the 100s across north-Central MT and the
upper 90s in Southwest MT. The ridge breakdown also brings an
increase in 700mb winds through Sunday, peaking late Saturday
night into early Sunday morning to 60-70kts along the Northern
Rocky Mountain Front. As a result, strong winds develop along the
Rocky Mountain Front windy conditions develop elsewhere Saturday
and Sunday. This with the combination of hot temperatures and low
relative humidity creates concerns for elevated to critical fire
weather conditions (see FIRE WEATHER section).

A mostly dry frontal passage Sunday will help bring a relief in
the heat through the first half of next week. Northwest flow
aloft will help keep temperatures down through Tuesday, before
very warm temperatures return. Low moisture throughout the week
will keep conditions dry.

 - Forecast Confidence & Scenarios:

Heat this Weekend:

There remains good confidence in impactful heat setting up
Saturday across the region, especially North-Central MT. Based on
recent temperature trends this week with the wildfire smoke, the
NBM may be running up to few degrees too hot for Saturday.
However, there is good confidence for widespread temperatures in
the 100s across North- Central MT Saturday. Therefore, the current
heat products remain on track.

Winds Saturday and Sunday:

Models have been consistent on the increase in winds and the
timing of peak winds. There is a 30-60% chance for 60 mph winds
along the immediate eastern slopes of the Rocky Mountain Front.
Although this is a typically windy region, it will be unusually
windy for the time of year, as wind gusts exceed the 95th
percentile for August. Therefore, these wind speeds are more
impactful for the time of year. The main impact will be for
outdoor recreation, particularly for Glacier NP and those
traveling in high profile vehicles. -Wilson

&&

.AVIATION...
31/12Z TAF Period

Main concern this TAF period will be wildfire smoke reducing slant-
range visibility across the region. A few showers and thunderstorms
look to develop near the Idaho border this afternoon, though
coverage continues to look too low to warrant a mention in the KWYS
TAF.

For KGTF: Diurnal mixing will result in a west to northwest wind
this afternoon and early evening. The overall magnitude of wind
looks to be 10 kts or less, yielding a low probability for cross
winds of 15+ kts. -AM

&&

.FIRE WEATHER...

Elevated to critical fire weather conditions is expected Saturday
afternoon through Sunday evening across North-Central, Central, and
Southwest Montana. On Saturday, hot temperatures in the upper 90s to
near 108 degrees will combine with minimum RH values as low as 8%
and frequent gusts of 25 to 40 mph with gusts up to 50 mph.
Higher gusts are expected along the Rocky Mountain Front to create
the potential for critical fire weather conditions. Sunday will
be cooler but low RH values and stronger winds than Saturday are
still expected which will still pose a significant concern not
only for ongoing fires but any potential new starts that occur. A
Fire Weather Watch remains in effect from Saturday afternoon
through Sunday evening across all of North-Central, Central, and
Southwest Montana. -thor/Wilson

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  96  61 103  62 /   0   0   0   0
CTB  91  54  97  55 /   0   0   0   0
HLN  95  61 101  60 /   0   0   0   0
BZN  94  58 102  57 /   0   0   0   0
WYS  88  47  92  48 /   0   0   0   0
DLN  90  56  95  55 /   0   0   0   0
HVR  97  57 106  62 /   0   0   0  10
LWT  92  59 100  60 /   0   0   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Watch from Saturday afternoon through late Saturday
night for Cascade County below 5000ft-Eastern Pondera and
Eastern Teton-Judith Basin County and Judith Gap.

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.

High Wind Watch from Saturday evening through Sunday morning for
East Glacier Park Region-Eastern Glacier, Western Toole, and
Central Pondera-Northern High Plains.

Extreme Heat Watch from Saturday afternoon through Sunday
morning for Bears Paw Mountains and Southern Blaine-Fergus
County below 4500ft-Western and Central Chouteau County.

&&

http://www.weather.gov/greatfalls