038
FXUS65 KTFX 081735
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1135 AM MDT Wed Oct 8 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Dry and mild conditions continue through Friday.

 - Windy and unsettled conditions develop this weekend ahead of a
   cold front arriving late Saturday, with increasing
   precipitation chances and lowering snow levels Saturday night.

 - Much cooler temperature Sunday and Monday with additional
   chances for precipitation through early next week.

&&

.DISCUSSION...
/Issued 647 AM MDT Wed Oct 8 2025/

 - Meteorological Overview:

Through Friday, a broad upper-level ridge will persist from the
Northern Rockies eastward across the Northern Plains. Meanwhile, an
upper-level trough extending from NW Canada southwestward off the
Pacific NW coast will split, leading to a large closed upper low
developing offshore by Friday. Mild and dry conditions will continue
for the remainder of the workweek under the upper ridge, with
daytime temperatures 10-15 degrees above seasonal averages.
As surface high pressure moves east across the Canadian Prairies,
winds will shift to the north and then east on the plains, bringing
slightly cooler, though still above-average, temperatures tonight
through Thursday.

The offshore upper low will transition into a trough and move
inland late Friday and Saturday. This will lead to increased
southerly flow, bringing windy conditions and an influx of
moisture by Saturday. Precipitation chances will rise late Saturday
with the arrival of a Pacific cold front. There is potential for
isolated thunderstorms ahead of the front due to instability,
followed by more widespread precipitation as a mid-level shortwave
lifts out of the trough through Sunday morning.

Significantly cooler air will follow the front, with snow levels
dropping and mountain snowfall likely late Saturday night into
Sunday morning. Sundays daytime temperatures are expected to remain
in the 40s (around 20 degrees colder than Saturday). Cool and
unsettled conditions, along with additional precipitation chances
(including potential for lower elevation snow), are anticipated to
persist through early next week as more energy enters the trough.
However, there is considerable uncertainty in ensemble solutions
regarding the troughs evolution next week.

 - Forecast Confidence & Scenarios:

Windy conditions are expected Saturday through Saturday night in
mixed southerly flow preceding the frontal passage, followed by a
westerly flow. Most areas have a 40-60% chance of wind gusts
exceeding 40 mph. However, areas along and near the Rocky Mountain
Front, including much of Glacier County, have a greater than 80%
chance of similar winds, with a 40-60% probability of gusts
surpassing 50 mph.

Atmospheric moisture levels (PWATs) are expected to be unusually
high, around 200% of normal, on Saturday and Saturday night. This
increased moisture will be available to interact with the cold front
and frontal wave arriving Saturday/Saturday night. The exact
location of this interaction is still uncertain, but if it coincides
with decreasing snow levels late Saturday night, it could result in
significant mountain snowfall, potentially affecting some passes.
Hoenisch

&&

.AVIATION...
08/18Z TAF...VFR conditions prevail at all terminals through the
TAF period with mostly clear skies and light flow as upper level
high pressure sits squarely over Montana. The exception is at
KEKS, which is seeing southerly gusts around 30 kts this
afternoon, likely aided by nearby terrain. Surface flow out of the
south and southwest today veers more easterly overnight
especially along the Hi- Line... however this flow will remain
light overall. -Casey

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  73  36  63  37 /   0   0   0   0
CTB  68  34  60  34 /   0   0   0   0
HLN  70  38  68  40 /   0   0   0   0
BZN  69  35  72  38 /   0   0   0   0
WYS  59  25  67  33 /   0   0   0  20
DLN  67  34  71  39 /   0   0   0  10
HVR  72  36  67  39 /   0   0   0   0
LWT  73  39  68  41 /   0   0   0   0

&&

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

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