Whitefish Mountain

000
FXUS65 KTFX 011118
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
518 AM MDT Sat Aug 1 2026

Aviation Section Updated.

.KEY MESSAGES...

 - After a hot day today, temperatures trend cooler into Sunday 
   behind a cold front. 

 - Critical fire weather conditions develop this afternoon, 
   persisting into Sunday. 

 - After a briefly cooler stretch behind the cold front, 
   temperatures trend back warmer mid-week.

&&

.DISCUSSION...
/Issued 119 AM MDT Sat Aug 1 2026/ 

 - Meteorological Overview:

Strong upper level ridging in place across the region will quickly 
be ushered eastward through the day today as an upper level trough 
slides east near the International Border. Ahead of the approaching 
trough temperatures rise well into the 90s across the region, 
reaching as high as 110F or so in typically heat prone areas. The
ongoing Extreme Heat Warnings and Heat Advisories are unchanged 
with this update. Those with plans outside today should plan for 
numerous breaks and for plenty of hydration. 

A dry cold front arrives as the upper level troughing moves eastward 
this afternoon. Ahead of the front, breezy southwesterly winds 
look to develop in many areas, transitioning to a more 
northwesterly direction behind the front late afternoon and into 
the evening. The strongest cross barrier flow aloft holds off til
this evening and tonight, peaking in excess of 60 kts along the 
Northern Rocky Mountain Front. The combination of cooling 
temperatures near the surface behind the front and still mild 
temperatures aloft will result in some ridgetop stability tonight 
along the Rocky Mountain Front. This will aid in translating the 
aforementioned stronger winds aloft to the surface in these areas 
via mountain wave activity. The strongest winds aloft fade quickly
after sunrise Sunday, though the continued brisk westerly flow 
aloft will keep gusty winds around through the day Sunday. 

A quick moving trough in wake of the initial troughing that will be 
exiting eastward by Sunday afternoon moves across the area Sunday
night. This trough looks to have enough moisture associated with 
it to result in a brief stretch of light precipitation along the 
Northern Rocky Mountain Front Sunday evening and overnight. 
Temperatures aloft look to be quite cool, which will yield the 
risk for some light snow near mountain peaks in Glacier NP over 
this timeframe. 

A cooler northwesterly flow aloft persists into the early week across 
the region, resulting in a below average temperatures across the 
region for a couple days. This trend looks to be short-lived however, 
as temperatures begin to trend warmer by mid-week. -AM

 - Forecast Confidence & Scenarios:

Strong winds tonight:

Ridgetop stability will yield a good setup for translating stronger 
winds to the surface tonight near the Rocky Mountain Front. Given 
the strongest winds aloft continue to take aim at the Northern Rocky 
Mountain Front, and largely only nick the Southern Rocky Mountain 
Front, no changes are being made to the ongoing High Wind Warning. 
Should the stronger winds aloft trend much further southward, 
additional High Wind Warnings may become necessary near the Southern 
Rocky Mountain Front. -AM

&&

.AVIATION...
01/12Z TAF Period 

The main concern this TAF period will be for breezy winds developing 
through the day and for a cold front to result in a wind shift this 
afternoon and evening across the region. Wildfire smoke will 
continue to result in slant-range visibility impacts, with surface 
visibility largely remaining VFR. Mountain wave activity increases 
near the Rocky Mountain Front after 00Z. 

For KGTF: Southwest winds on the order of 15 kts through mid-
afternoon will result in little to no cross-winds ahead of a cold 
front. The cold front looks to arrive between 21Z Sat and 00Z Sun, 
which would shift winds northwesterly. The probability that 
crosswinds exceed 15 kts is less than 10% before 21Z Sat, but 
rapidly rises to 70% after 21Z. 

The gusty northwest winds slowly diminish near and after sunset. 
Mountain wave activity cannot be ruled out near KGTF beginning late 
evening Saturday, persisting into Sunday morning. -AM

&&

.FIRE WEATHER...

Critical fire weather conditions are forecast this weekend across
all fire weather districts.
 
Gusty winds developing this afternoon ahead of a dry cold front will 
combine with relative humidities approaching single digits to result 
in critical fire weather conditions in most areas. Winds shift to a 
more northwesterly direction this afternoon and evening behind the 
cold front. While gusty winds diminish somewhat out over the plains 
tonight, strong winds will develop along the Rocky Mountain Front 
this evening, slowly expanding over the plains through the night and 
into the day Sunday. Overnight humidity recovery is forecast to be 
nearly non-existent where these winds are persistent overnight near 
the Rocky Mountain Front.

Although cooler temperatures will be moving in behind the cold front 
for Sunday, very low relative humidity will persist (Approaching 
single digits once again). Combine this with forecast breezy
winds, and critical fire weather conditions will be around once 
again for Sunday. -AM

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF 103  63  85  50 /   0   0   0   0 
CTB  97  55  75  45 /   0   0   0   0 
HLN 100  60  84  50 /   0   0   0   0 
BZN 101  57  90  49 /   0   0   0   0 
WYS  91  48  86  40 /   0   0   0   0 
DLN  95  55  88  47 /   0   0   0   0 
HVR 106  62  86  48 /   0   0   0   0 
LWT 101  61  85  49 /   0   0   0  30 

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon today to 9 PM MDT Sunday 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.

Heat Advisory from noon today to 3 AM MDT Sunday for Beaverhead 
and Western Madison below 6000ft-Canyon Ferry Area-Eastern 
Glacier, Western Toole, and Central Pondera-Eastern Pondera and 
Eastern Teton-Eastern Toole and Liberty-Elkhorn and Boulder 
Mountains-Gates of the Mountains-Helena Valley-Hill County-
Meagher County Valleys-Missouri Headwaters-Northern Blaine 
County-Snowy and Judith Mountains.

High Wind Warning from 6 PM this evening to noon MDT Sunday for 
East Glacier Park Region-Eastern Glacier, Western Toole, and 
Central Pondera-Northern High Plains.

Extreme Heat Warning from noon today to noon MDT Sunday for 
Bears Paw Mountains and Southern Blaine-Fergus County below 
4500ft-Western and Central Chouteau County.

Extreme Heat Warning from noon today to 3 AM MDT Sunday for 
Cascade County below 5000ft-Gallatin Valley-Judith Basin County 
and Judith Gap-Madison River Valley.

&&

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