696
FXUS65 KTFX 171922
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
122 PM MDT Thu Jul 17 2025

.KEY MESSAGES...

 - Scattered thunderstorms, with a few strong to severe
   thunderstorms, will move across the plains of Central and North
   Central Montana this afternoon and evening. The strongest
   storms will be capable of producing large hail and damaging
   winds.

 - Showers and thunderstorms will be possible once again on
   Friday, mainly across Southwest Montana, with the main threat
   being gusty and erratic winds.

 - Temperatures will continue to moderate through the first half
   of the upcoming weekend.

&&

.DISCUSSION...

 - Meteorological Overview:

A small shortwave aloft moving through late this afternoon and
evening will allow for the development of scattered showers and
thunderstorms across the Hi-line and portions of North-Central MT.
Increasing deep layer shear should allow for isolated severe storms,
with hail and strong winds as the main hazards. For Friday, another
shortwave moves through, which will allow for isolated to scattered
showers and thunderstorms across Southwest MT along and south of I-
90. Deep inverted V`s will help bring an isolated strong wind threat
with storms.

Zonal flow aloft continues through the weekend, which will keep
low end precipitation chances mainly in Central MT. Saturday`s
best chances look for strong to severe thunderstorms look to stay
off into Eastern MT, but any westward shifts in precipitation can
increase thunderstorm chances for Central MT. Temperatures
continue to gradually warm back close to normal through the rest
of the weekend. Ensembles hint at a troughing pattern for next
week, which will keep precipitation chances in the forecast, but
disagreements on the evolution of this troughing pattern makes
any details about precipitation unclear at this time. - Wilson

 - Forecast Confidence & Scenarios:

Thunderstorms through this evening :

Hi-Res models continue to support the development of thunderstorms
across Southwest Alberta and near the Glacier National Park region
between noon and 2 PM MDT, with this activity moving to the
southeast and across portions of the North Central Montana plains
through the remainder of the afternoon and early evening hours
tonight. Thunderstorms will be capable of producing large hail and
damaging winds northeast of a East Glacier, to Conrad, to Fort
Benton, to Fergus line; with large hail probabilities being the
highest in the Havre, Chinook, Harlem, Fort Belknap, and Hays
communities between 3-9 PM MDT. - Moldan

Thunderstorms on Friday :

Thunderstorms Friday look be be mainly confined along and south
of the I-90 corridor. Deep inverted V sounding profiles and 1,000
j/kg of DCAPE do support the potential for a few stronger wind
gusts with storms. Precipitation chances for the weekend overall
is low/isolated across the region. -Wilson

&&

.AVIATION...
17/18Z TAF Period

Afternoon and evening thunderstorms are forecast to occur across
the Hi-Line and vicinity, where thunderstorms capable of hail,
lightning, and gusty and erratic winds develop.
AM / Fogleman

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  53  83  57  87 /  20   0   0   0
CTB  49  77  55  80 /  30  10  10  10
HLN  51  88  54  88 /   0   0   0   0
BZN  46  89  50  91 /   0  20  30  10
WYS  38  81  41  81 /  10  40  30  10
DLN  46  87  48  89 /   0  30  20  10
HVR  52  81  58  88 /  60  10   0  10
LWT  48  78  53  84 /  10  10  20  10

&&

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

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