647
FXUS65 KTFX 021742
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1142 AM MDT Tue Sep 2 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Hot temperatures will remain in place today and tomorrow before
   cooling down on Thursday and Friday.

 - Wildfire smoke from Canada will continue to impact much of the
   region over the next couple days.

 - Generally dry conditions expected for much of the region
   through Friday with increasing chances for precipitation this
   weekend.


&&

.UPDATE...
/Issued 824 AM MDT Tue Sep 2 2025/

A few light showers will continue along the Hi-Line in Blaine
County this morning due to the front. Other than a few isolated
orographic induced showers along the Continental Divide this
afternoon, the rest of the region looks to remain dry. The front
moving south today will bring in some smoke from Canada. -Wilson

&&

.DISCUSSION...
/Issued 824 AM MDT Tue Sep 2 2025/

 - Meteorological Overview:

An upper level ridge will persist over the region today and
tomorrow allowing for temperatures to climb into the upper 80s to
low 90s across the lower elevations of north-central, central, and
southwest Montana. In the meantime, a strong upper level trough
will start to make its way out of southern Canada towards the
Great Lakes region. Even though central Montana is west of the
main impacts from this trough, a cold front is still expected to
pass through Wednesday evening into Thursday morning bringing
cooler temperatures and gusty winds. Cooler temperatures will last
through Friday but as the trough continues to make its way east the
ridge will try to build back just enough to allow some warmer
temperatures to return. But by Sunday into Monday, another trough
moves in flattening the ridge and allowing for a chance of
precipitation this weekend into early next week.


 - Forecast Confidence & Scenarios:

Showers Today:

As of 2 AM, there are light showers moving out of southern Alberta
into north-central Montana which will continue over the next few
hours. Generally minimal accumulations are expected with these
showers.

There is a less than 10% chance for some afternoon showers along
the Rocky Mountain Front. As of now, there was not enough
confidence in the cap breaking to warrant modifying the
precipitation chances beyond what the NBM had. Should the cap
break, expect some pop-up showers that may produce minimal amounts
of precipitation and some brief gusty outflows generally less than
40 mph.


Wildfire Smoke:

The latest run of the models shows a major push of Canadian
wildfire smoke into Montana with the worst of the impacts expected
along the northern half of the state. Air quality will be degraded
at times which may impact those who are sensitive to smoke.
Significant impacts to surface-level visibility are not expected
over the next couple days but isolated areas of denser smoke could
drop local visibilities below 5 miles at times.

While the smoke models currently only run through Wednesday
afternoon, northerly flow is expected to persist through Friday
evening meaning the impacts from smoke could last that long as
well. Friday evening into Saturday morning, the northerly flow
starts to weaken which, at the very least, should stop the influx
of more smoke from Canada. But depending on how local fires fare
there may be some lingering localized smoke impacts. For now, the
finer details remain uncertain but the highest confidence for
smoke impacts is now through Thursday afternoon.  -thor


&&

.AVIATION...
02/18Z TAF Period.

While VFR conditions are expected to prevail this afternoon and
evening, smoke from Canadian wildfires will continue to push into
the area from the north. As of now, MVFR visibility has been
reported in KCTB with an area of similar visibility expected to
advect across the plains through the afternoon. Be aware that
slantwise visibility may be reduced further due to smoke. Ludwig

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  88  54  87  56 /   0   0   0   0
CTB  82  50  86  54 /   0   0   0   0
HLN  90  57  91  57 /   0   0   0   0
BZN  89  51  88  52 /   0   0   0   0
WYS  80  40  81  40 /  10   0   0   0
DLN  85  50  87  50 /   0   0   0   0
HVR  84  50  79  56 /  10   0   0   0
LWT  85  50  80  54 /   0   0   0   0

&&

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

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