782
FXUS65 KTFX 261506
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
906 AM MDT Sat Jul 26 2025

.KEY MESSAGES...

 - A daily risk of showers and thunderstorms continues through
   next week.

 - A few strong to severe thunderstorms may develop each afternoon
   this weekend with damaging wind gusts the primary hazard in
   addition to lightning.

 - Temperatures fluctuate close to seasonable norms for late July
   through the upcoming week.

&&

.UPDATE...

No significant changes in thoughts this morning on the risk of
showers and thunderstorms producing gusty winds today. Convective
initiation looks to be early to mid afternoon across portions of
Southwest Montana. Activity spreads north and northeastward with
time, eventually reaching the plains late afternoon into the early
evening. A few high resolution guidance members have been a bit
more aggressive with forming a few thunderstorms east of the
Rocky Mountain Front this afternoon in an area of better shear.
The risk is conditional, but should a thunderstorm form in this
area, the environment appears to be at least marginally conducive
for a supercell.

The forecast is handling this well, with only minor changes made
this morning. -AM

&&

.DISCUSSION...
/Issued 502 AM MDT Sat Jul 26 2025/

 - Meteorological Overview:

The area remains under a general southwest flow aloft between a
large scale ridge that gradually migrates from the southeast US
westward across the US Plains through next week, while an upper
level trough remains anchored along the West coast. Subtle
disturbances ejecting out of the western trough and available
mid-level moisture and instability will lead to daily shower and
thunderstorm development through much of the week ahead under this
relatively persistent pattern.

Temperatures remain fairly warm today (mid-upper 80s) with a dry
and deeply mixed boundary layer (particularly across SW MT)
supporting initially high-based convection with an environment
favorable for strong wind gusts, even as storms track northward
and encounter somewhat better low level moisture across north-
central MT this evening. Higher low-level moisture (50F+
dewpoints) and slightly better wind shear (30-40kts) across
north-central MT may allow for some more organized/intense storms
early this evening with locally heavy downpours and small hail in
addition to the larger wind threat, though freezing levels around
14kft will likely keep the threat for larger hail limited.

While confidence in particular details decreases Sunday through
next week, the overall mid-upper level setup changes little. Low
level east to southeast flow does look to bring additional low-
level moisture into the area next week, supporting an increased
chance for localized heavier precipitation beneath storms as the
week progresses. Hoenisch

 - Forecast Confidence & Scenarios:

Thunderstorms today should initiate early this afternoon across
the SW MT mountains and track northeast in the southwesterly
steering flow with the greatest coverage across central MT early
this evening (5pm-9pm). Hi-resolution model ensembles support a
40-60% chance of wind gusts in excess of 40 mph associated with
storms across central MT late this afternoon/evening with 10-20%
risk of gusts in excess of 55 mph centered on an area from the Big
Belt Mtns northeast across the Little Belts and the Judith Basin
area. Hoenisch

&&

.AVIATION...
26/12Z TAF Period

VFR conditions prevail across the region to start the TAF period
with some low clouds banked against the Rocky Mtn Front early
this morning, but otherwise just some scattered mid-high level
clouds. Showers and thunderstorms develop across southwest MT
early afternoon and track across central and north-central MT late
this afternoon and evening. In addition to gusty/erratic winds
and lightning, some cells across central/N-central MT could
include brief heavier precipitation with local terrain obscuration
and isolated small hail. Hoenisch

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  86  56  84  56 /  30  30  10  20
CTB  79  50  77  52 /  20  10  10  20
HLN  87  55  86  56 /  50  40  30  30
BZN  90  51  88  51 /  40  20  20  20
WYS  82  39  80  39 /  10  10  10   0
DLN  84  47  84  48 /  40  20  30  10
HVR  88  55  85  56 /  20  20   0  30
LWT  85  53  81  53 /  40  50  20  40

&&

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

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