Wildfire in Montana, August 13 to 31, 2025

Area Forecast Discussion
National Weather Service Great Falls MT
155 PM MDT Wed Aug 13 2025

.KEY MESSAGES...

- Hot, dry, and windy conditions continue through the rest of the
  afternoon.

- Isolated showers and thunderstorms are possible this today near
  the MT and ID border, and Thursday morning across the Hi-Line.

- Cooler conditions are expected tomorrow, with a warming trend
  after through the weekend.

&&

.DISCUSSION...

 - Meteorological Overview:

Westerly flow aloft today will continue to bring breezy to windy
west winds and hot temperatures this afternoon. Isolated showers
and thunderstorms develop this afternoon near the MT/ID border.
A few gusty winds and lightning will be the main concerns with
precipitation.

Hot temperatures won't last for too much longer as
a cold front will slide south from Canada through North- Central
MT later tonight through Thursday morning. This will bring cooler
temperatures to North- Central MT for Thursday, dropping to below
normal. The front is expected to stall a bit before reaching
Southwest MT, so temperatures will remain in the upper 80s to low
90s across lower elevations over there. Breezy conditions are also
expected tomorrow, mainly in Southwest MT. However, it won't be
as hot, windy, or dry as it is today. This cold front will also
try to develop isolated showers along the Hi-line tomorrow,
mainly near the MT and Canadian border. A mini shortwave along the
MT/ID border will bring another round of isolated to scattered
showers near the ID border tomorrow afternoon.

Heading into the weekend, a southwest flow aloft pattern returns as
an upper-level ridge builds in across the Great Plains of the U.S.
This will help warm temperatures back to above normal. Being on the
western extent of the ridge, there will be a few embedded waves
that will lift north through the Western CONUS and develop
precipitation Saturday and Sunday. Sunday look to be the best
chances for afternoon and evening showers and thunderstorms when
the more potent shortwave passed through. This southwest flow
aloft pattern continues into next week, keeping the above average
and low end chances for precipitation.

 - Forecast Confidence & Scenarios:

There's a little uncertainty for overnight precipitation along
the MT/Canadian border and the MT/ID border. Models keep most of
the precipitation just off to the north into Canada. However with
that cold front passage, I cannot rule out a few showers clipping
northern MT. There is a similar case for the MT/ID border. Hi-res
models keep shower activity to the south in ID, but any northern
trends may result in low end PoPs down the line. For winds
tomorrow in Southwest MT, there's a 30-50% chance for 30 mph winds
in the valleys along and south of the I-90 corridor. -Wilson

&&

.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...

Elevated fire weather concerns continue this afternoon as hot, dry,
and windy conditions have set up across the region. The area with
the most concern will be Southwest MT, where fuels are drier and
more critical. Although fuels aren't at critical thresholds in
North-Central MT, the hot, windy, and dry conditions this
afternoon will continue to cause an elevated risk for fire spread.
Elevated fire weather concerns decrease tomorrow across North-
Central MT with cooler temperatures and lighter winds. Down
towards Southwest MT, breezy winds and warmer temperatures set in
again, which will keep elevated fire weather concerns for
Thursday. -Wilson

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  57  80  54  85 /   0  10   0   0
CTB  52  72  51  77 /  10  10   0   0
HLN  57  87  55  87 /   0   0   0   0
BZN  53  90  50  90 /   0   0   0   0
WYS  41  82  40  82 /  10  20  10  10
DLN  49  87  47  88 /   0   0   0   0
HVR  56  76  54  83 /  10  10  10  10
LWT  55  77  52  82 /   0  10  10  10

&&

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

http://www.weather.gov/greatfalls