446
FXUS65 KTFX 142348
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
548 PM MDT Mon Sep 14 2026

Aviation Section Updated.

.KEY MESSAGES...

 - Gusty winds today, especially along the Rocky Mountain Front
   and north central MT.

 - Areas of showers at times through Monday night, the potential
   for showers/thunderstorms then return Thursday afternoon
   through Saturday.

 - Beginning Thursday, widespread warmer temperatures are
   expected.

&&

.UPDATE...

Although daytime mixing is peaking or has recently peaked across
the region, mid level flow is on the decrease. Given this is the
case, the High Wind Warning for Fergus and Judith Basin counties
is being allowed to expire at 6 PM. Showers look to continue over
portions of the plains through the evening as the responsible
upper level system continues to depart east.

Although some mid and upper level cloudiness looks to persist and
largely inhibit fog, a patchy mention was added to the forecast in
some low-lying areas for Tuesday morning. All in all, the forecast
is in good shape with minimal edits made with this evening. -AM

&&

.DISCUSSION...
/Issued 105 PM MDT Mon Sep 14 2026/

 - Meteorological Overview:

As the upper-level low continues its easterly track out of the
region, it will be followed by a weaker upper-level ridge. This
ridge will bring a period of milder winds and overall drier
conditions Monday night through Wednesday night, although areas
of showers can`t be ruled out. As a weaker upper-level low moves
easterly into the region Thursday afternoon/evening, it is
expected to bring widespread shower and thunderstorm potential.
The low will continue to track easterly through the region over
Friday and Saturday, which will allow for the potential of showers
and thunderstorms to continue. An upper-level ridge will follow
this upper-level low, bringing warm, dry, and milder weather on
Sunday and Monday. -ESH

 - Forecast Confidence & Scenarios:

Main concern will be strong wind gusts over 55 mph today. Fergus
county continues to have the highest potential (areas of 70%<
chance of 24 hr max wind gusts at or above 55 mph), so it
continues to have a High Wind Warning until 6 pm MDT.

For the shower event beginning Thursday afternoon/evening and
continuing through Saturday, highest totals are expected in the
southern half of the region (around 50% chance of rain totals .25"
or above between Thursday 6 AM- Saturday 6 AM MDT).

Current time period for highest thunderstorm probability is 12 pm
Friday-12 am Saturday MDT, 20-35% chance across the region. -ESH


&&

.AVIATION...
15/00Z TAF Period

Initial concern will be for gusty northwest winds to diminish
through 06Z across the region. A few showers and associated lower
clouds will be around through 03Z or so before diminishing into the
remainder of the evening. Looking ahead to Tuesday, daytime mixing
will result in some low-VFR or MVFR ceilings at times over the
plains. Mountains may be obscured at times this TAF period. -AM

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  41  64  45  59 /  20   0  20  20
CTB  41  57  42  57 /  20  10  70  10
HLN  40  69  45  65 /  10   0  10   0
BZN  36  71  39  70 /   0   0   0   0
WYS  26  66  30  72 /   0   0   0   0
DLN  34  72  37  71 /   0   0   0   0
HVR  41  66  45  65 /  20   0  70  10
LWT  39  65  41  61 /  30   0  10   0

&&

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

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