212
FXUS65 KTFX 182337
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
537 PM MDT Fri Jul 18 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Warm, with a few scattered thunderstorms over the weekend.

 - Cooler and wetter conditions expected Monday and Tuesday across
   north-central Montana.

 - Warmer and drier conditions return by late next week.

&&

.DISCUSSION...
/Issued 148 PM MDT Fri Jul 18 2025/

 - Meteorological Overview:

Westerly flow aloft will continue through the weekend with near-
normal temperatures and daily chances for isolated to scattered
afternoon thunderstorms. Wetter and cooler conditions will return
Monday and Tuesday as an upper level trough makes its way across the
northern portion of the state. Heading towards next weekend, upper
level ridging builds across the central CONUS allowing for
temperatures to warm back up to near to slightly above normal by
Thursday.


 - Forecast Confidence & Scenarios:

Wildfire Smoke:

Smoke from active wildfires in Idaho is expected to drift over
southwest Montana today and tomorrow. In general, significant
impacts are not expected at this time, however, there may be some
reduced air quality at times particularly in Beaverhead county.


Thunderstorms Today/Tomorrow:

Thunderstorms are already underway across southwestern Montana and
will continue through the rest of the afternoon. The main concern
will be gusty winds up to 50 mph with isolated higher gusts
possible. Lightning will also be a concern as, in general, these
storms are not expected to produce much in the way of precipitation
but may have a few cloud-to-ground strikes that cause concern for
fire starts.

With regards to tomorrow afternoon, there is a chance for afternoon
thunderstorms along the International Border. The greatest risk for
stronger storms will be in Hill and Blaine counties after 2 PM where
storms will form before moving off to the east by about 6 PM.


Monday/Tuesday Rain:

Model guidance continues to suggest that the system moving through
early next week will primarily impact locations north of I-90 with
locations to the south staying dry through this time period.
Locations north of a line between Helena and the southern Fergus
county border have a 60-80% chance of seeing 0.10" and a 30-50%
chance of seeing 0.25".   -thor

&&

.AVIATION...
19/00Z TAF Period

Primarily VFR conditions are expected for this TAF period;
however, widely scattered showers and thunderstorms will continue
over Southwest Montana through 19/04Z, mostly along and south of
I90. Localized gusty and erratic winds in excess of 30 kts will be
the primary hazard with this activity. Another shortwave will
bring a few isolated showers or storms along the Canadian border
tonight into Saturday morning. Otherwise, most areas will just
see some westerly breezes and passing mid- to higher level clouds
on Saturday. - RCG

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  58  84  56  83 /   0  10   0   0
CTB  55  76  49  76 /  10  10  10  10
HLN  57  86  57  83 /   0  10   0  10
BZN  52  89  52  88 /  10  10   0  10
WYS  42  80  42  80 /  30  10   0  10
DLN  49  83  49  83 /  10  10   0  10
HVR  58  86  54  84 /  10  20  10  10
LWT  55  82  52  78 /  10  10  10  20

&&

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

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