Simms, Montana Weather Forecast Discussion

230
FXUS65 KTFX 231940
AFDTFX
Area Forecast Discussion
National Weather Service Great Falls MT
140 PM MDT Tue Sep 23 2025
.KEY MESSAGES...
- Remaining dry through the weekend.
- Mild temperatures persist through the weekend, with the two
   hottest days Wednesday and Thursday.
- Breezier period Thursday into Friday, mostly over the plains
   west of I-15.
&&
.DISCUSSION...
- Meteorological Overview:
A building upper level ridge across the region is allowing for a
largely cloud free sky today, while allowing for temperatures to
trend warmer. Ridging continues into Wednesday and much of Thursday,
allowing for temperatures to climb another step those days while
skies remain sunny.
Low amplitude troughing slides east southeast from off the BC coast
toward the Northern Rockies toward the back end of Thursday, which
will result in an increased zonal flow aloft. Breezy winds look to
develop ahead of this troughing over the plains, with areas along
the Rocky Mountain Front looking the most breezy.
As the base of the troughing passes across the region Thursday
night, a cold front looks to move through. Temperatures heading
into Friday look to drop a bit, but still be on the mild side,
while winds shift to a more northwesterly direction. The wind
shift and slight cool down are the two impacts from this
troughing, as better support for any light precipitation looks to
remain north in Canada.
Upper level ridging looks to become established once again behind
the departing trough this weekend, promoting another dry and mild
stretch. By early nest week an increasing share of ensemble members
are favoring troughing off the Pacific coast, though there remains
significant discrepancies on its east-west positioning. The further
east this troughing sets up, the higher the likelihood for a
cooldown and return of precipitation chances, while a further west
solution would favor a warmer/drier stretch continuing. -AM
- Forecast Confidence & Scenarios:
Through Sunday the greatest uncertainty is with respect to wind
strength Thursday into Friday. Deterministic guidance continues to
favor strong cross barrier flow (H7 45-55 kts), particularly
Thursday night. Although this is the case, the timing (Not well
mixed) and lack of ridgetop stability both contribute to these
stronger gusts not being efficiently translated to the surface.
Hence, the chance for a 55+ mph gust along the Rocky Mountain
Front and adjacent plains is overall quite low, peaking around 10
to 20% even in the most wind prone areas such as between Heart
Butte and Browning, as well as between Browning and St Mary on
US-89.
Heading into next week the main story will be tied to the placement
of a developing trough off the Pacific NW coast as well as the
timing and strength of the troughing as it eventually moves east
toward the Northern Rockies. -AM
&&
.AVIATION...
23/18Z TAF Period
VFR conditions will prevail at all terminals across Southwest,
Central, and North Central Montana through the 2318/2418 TAF
period. Mountain obscuration is not expected over the next 24
hours. - Moldan
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF  49  87  45  87 /   0   0   0   0
CTB  45  84  40  82 /   0   0   0   0
HLN  45  84  48  85 /   0   0   0   0
BZN  40  80  43  82 /   0   0   0   0
WYS  28  70  29  72 /   0   0   0   0
DLN  38  79  41  81 /   0   0   0   0
HVR  45  85  44  84 /   0   0   0   0
LWT  45  84  46  83 /   0   0   0   0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls

NWS TFX Office Area Forecast Discussion