134
FXUS65 KTFX 112113
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
213 PM MST Tue Nov 11 2025

.KEY MESSAGES...

- Above average temperatures generally continue for the remainder
  of the week, with near record high temperatures expected on
  Thursday.

- A Pacific weather system will bring periods of breezy to windy
  conditions and mountain snow opportunities later Thursday
  through Saturday.

- Cooler temperatures move in early next week with more unsettled
  conditions.

&&

.DISCUSSION...

 - Meteorological Overview:

Ridging aloft builds in over the next day or so and will bring a
lighter wind regime for a short period. Other than a warm front
swinging through the region tonight into Wednesday and bringing
some areas of light rain/snow along and west of the Continental
Divide, dry and mild conditions will prevail, with near record
highs on Thursday. West to southwesterly flow aloft increases in
advance of the Pacific trough for breezy to windy conditions
Thursday and Friday, mostly along the Rocky Mountain Front and in
the normally wind prone southwest valleys.

The main trough is progged to pass through The Northern Rockies
Thursday night through Saturday, although the main low looks to
shear off and dive southeastward into the Great Basin and
southwestern CONUS. This may slow the progression of the system
and should reduce its overall precipitation capacity. Regardless
there is still the expectation for periods of mountain snow and
some lower elevations showers, especially over the southwest.

Ensembles agree with the general unsettled pattern continuing
into next week, but there are considerable differences among
members with timing and depth of the passing Pacific troughs due
to their complex shearing/splitting evolutions. Overall,
temperatures look to trend closer to average while opportunities
for mostly mountain snow present themselves during trough
passages. - RCG

 - Forecast Confidence & Scenarios:

Windy conditions Thursday and Friday...

Upper level winds quickly increase on Thursday in advance of the
approaching trough. H700/500 winds increase to the 45 to 65 kt
range along the Rocky Mountain Front by the early afternoon hours.
The southwesterly trajectory of the flow will favor the Northern
Rocky Mountain Front and the adjacent plains extending eastward
toward I15 Thursday and Thursday night. In theory the stronger
winds aloft combined with mountain wave activity will bring wind
gusts up to 75 in these areas, but this shift in trends is fairly
recent, so Ideally I would like to see some temporal consistency
among ensemble members to gain confidence, along with higher wind
exceedance probabilities than the current 20 to 40% chance for 75
mph or higher gusts. A southerly H700 jet will also bring gusty
winds over 40 mph to the normally wind prone southwest valleys,
including the Dillon and Ennis areas.

A Pacific cold frontal passage and continued strong H700/500 flow
should bring gusty westerly winds for all areas on Friday.
Widespread gusts in the 35 to 55 mph range, and even higher over
the plains, seems plausible given the conditions; however, there
are some caveats to consider, most significantly the timing of the
Pacific front during the day on Friday and then the Canadian
front currently progged to move southward into the plains Friday
evening.

Mountain snow and lower elevation showers Thursday night through
Saturday...

Mountain snow is not as big of a concern with a significant
portion of the incoming trough diving southeastward into the Great
Basin. Regardless there will be be at least some mountain snow to
monitor, mostly along the Continental Divide and the southwest
mountains. The probability for 4 inches of snow or more are
highest (50 to 60%) above pass level along the Northern Rocky
Mountain Front. There will be the presence of lighter end showers
for lower elevations, mostly over southwest MT. - RCG

&&

.AVIATION...
11/18Z TAF Period

A moderate westerly flow across the Northern Rockies will
continue to produce some mountain wave turbulence across the area
along with gusty surface winds at KCTB and KGTF through this
afternoon before flow aloft and surface winds decrease more
noticeably by this evening. Scattered to broken mid-level clouds
across southwest MT this morning will continue to decrease this
afternoon with VFR conditions prevailing at all terminals.
Hoenisch/Ludwig

The KWYS TAF will not be issued until airport operations resume
next spring.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  34  59  42  67 /   0  10   0   0
CTB  28  53  36  63 /   0  10   0   0
HLN  37  59  37  65 /   0   0   0   0
BZN  33  60  34  64 /   0   0   0   0
WYS  24  50  26  51 /   0   0   0   0
DLN  34  58  33  61 /   0   0   0   0
HVR  27  51  31  66 /   0  10   0   0
LWT  32  61  40  66 /   0   0   0   0

&&

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

$$
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