848
FXUS65 KTFX 052252
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
452 PM MDT Sun Oct 5 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Lingering light snow through the afternoon and early evening.

 - Cold overnight temperatures Monday morning alongside at least
   patchy fog.

 - Trending warmer and drier Monday and Tuesday as upper level
   ridging builds in.

&&

.DISCUSSION...
/Issued 211 PM MDT Sun Oct 5 2025/

 - Meteorological Overview:

A cold upper trough sliding southeastward is beginning to exit the
region as of this afternoon. Lingering light snow (And isolated
snow showers near the Idaho border) and clouds will give way to
clearing skies this evening and tonight as the upper trough moves
eastward and upper level ridging builds in. Although the ridging
will begin to move in tonight, cold temperatures will hang around
long enough to result in lows largely in the 20s and low 30s
tonight at lower elevations. Clearing skies combined with recent
precipitation will also result in at least patchy fog in areas
where wind remains calm tonight.

Temperatures trend warmer Monday and reach above average by Tuesday.
Persistent upper level ridging will keep the area dry and mild
through the week, though Thursday looks briefly cooler on portions
of the plains behind a front.

Confidence in specifics wanes toward next weekend, but ensembles do
favor a period of upper level troughing moving in off the Pacific
Northwest coast toward the Northern Rockies. This would favor
temperatures cooling back down with opportunities for precipitation
returning. -AM

 - Forecast Confidence & Scenarios:

Confidence in the forecast is high through the week. Uncertainty
builds in toward the weekend associated with upper troughing over
the Pacific Northwest. East-west uncertainty is apparent, though a
bit higher confidence than strength of the trough. Around 20% of
ensemble members have a more potent trough. This scenario would
favor a more dynamic system capable of producing greater
precipitation amounts. A more potent system would also feature a
greater chance for a period of strong winds. Nonetheless, a trend
toward cooler temperatures is reasonable for the weekend, with
opportunities for precipitation returning. -AM

&&

.AVIATION...
06/00Z TAF Period

MVFR/VFR CIGS through 03z this evening will give way to VFR CIGS
thereafter as surface high pressure continues to build in over
Montana, with skies clearing from north to south. Biggest concern
as skies clear will be the potential for fog development,
particularly in the valleys of Southwest Montana and near the KGTF
terminal. Any fog that does develop is likely to linger at or near
a given terminal through 15-18z Monday. Mountain obscuration will
decrease across North Central and Central Montana through 03-06z
Monday and 06-12z Monday across Southwest Montana. - Moldan

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  28  58  34  69 /   0   0   0   0
CTB  24  58  31  66 /   0   0   0   0
HLN  27  58  33  66 /   0   0   0   0
BZN  26  55  27  64 /  10   0   0   0
WYS  17  52  17  58 /  20   0   0   0
DLN  25  55  29  64 /   0   0   0   0
HVR  26  61  34  70 /   0   0   0   0
LWT  26  57  32  67 /   0   0   0   0

&&

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

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