Damaging Winds in Montana, June 25 to 27, 2025

Area Forecast Discussion
National Weather Service Great Falls MT
245 PM MDT Wed Jun 25 2025

.KEY MESSAGES...

 - Isolated showers and thunderstorms will affect the area each
   afternoon/evening today through Saturday with isolated strong
   to severe thunderstorms tomorrow.

 - It will be mostly dry Sunday through early next with
   temperatures warming up to well-above normal by the middle of
   next week.

&&

.DISCUSSION...

 - Meteorological Overview:

This afternoon there will be an upper-level ridge over North-
central, Central, and Southwestern Montana. A weak upper-level
disturbance will move through the upper-level flow and bring
isolated showers and thunderstorms to North-central Montana this
afternoon through this evening. On Thursday an upper-level shortwave
will move over North-central, Central, and Southwestern Montana.
This will bring showers and thunderstorms to much of the area
Thursday afternoon and evening. Across portions of North-central and
Central Montana there will be isolated strong to severe
thunderstorms Thursday afternoon and evening. On Friday the upper-
level flow over North-central, Central, and Southwestern Montana
transitions to zonal flow. The zonal flow will remain over the area
on Saturday. This will bring another round of showers and
thunderstorms to North-central, Central, and Southwestern Montana on
Friday and Saturday afternoon and evening.

On Sunday an upper-level ridge builds in over North-central,
Central, and Southwestern Montana. This will warm up temperatures
and bring mostly dry weather to the area on Sunday. On Monday the
upper-level ridge remains over North-central, Central, and
Southwestern Montana which will keep mostly dry weather and warm
temperatures up further. On Tuesday the upper-level ridge remains
over North-central, Central, and Southwestern Montana. This combined
with southwest flow aloft will bring showers and thunderstorms to
the area Tuesday afternoon and evening.

 - Forecast Confidence & Scenarios:

The Storm Prediction Center has issued a Marginal Risk (5% chance
for severe wind gusts of 58 mph or greater) across areas north of I-
90 excluding Glacier County tomorrow. On Friday there is a 20 - 50%
chance for thunderstorms along and south of the US Highway
87/Montana Highway 200 Corridor. On Saturday there is a 15 - 35%
chance for thunderstorms in Southwestern Montana. On Sunday and
Monday there is a 10 - 30% chance for thunderstorms across North-
central, Central, and Southwestern Montana. On Tuesday there is a 20
- 50% chance for thunderstorms across North-central, Central, and
Southwestern Montana.

There is high confidence in the overall weather pattern until
Tuesday when deterministic models and ensembles begin to diverge.
One scenario is that across the area there will be widespread strong
to severe thunderstorms Tuesday afternoon with a cool down for
next Wednesday. Another scenario is that it remains hot with
scattered showers and thunderstorms on Tuesday and next Wednesday. -IG

&&

.AVIATION...
25/18Z TAF Period

VFR conditions continue for all airfields throughout this 25/18Z
TAF period. Winds are, generally, light and variable, with KCTB
forecast to experience periods when winds gust southwesterly to 25
mph. This afternoon and evening, there is a slight (< 25%) chance
for showers and a few thunderstorms across higher elevations of
central and north central Montana. Virga should be expected.
Tomorrow afternoon and evening, there is a 30% to 40% chance for
showers and thunderstorms to move across the region from southwest
to northeast. With warming summer temperatures, density altitude
becomes and issue.
- Fogleman

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  53  82  54  80 /  30  40  20  20
CTB  52  76  53  73 /  20  40  10  10
HLN  54  81  55  80 /  10  50  20  30
BZN  50  85  50  83 /   0  30  10  20
WYS  36  75  38  74 /   0  10  10  10
DLN  48  79  49  81 /  10  30  10  10
HVR  54  85  55  82 /  10  20  20  10
LWT  52  80  51  76 /  10  60  30  40

&&

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

http://www.weather.gov/greatfalls