559
FXUS65 KTFX 031135
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
435 AM MST Mon Nov 3 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Intermittent opportunities for precipitation this week, largely
   favoring the Continental Divide and adjacent areas.

 - Breezy Tuesday for Central and Southwest Montana ahead of
   another breezy period for most areas toward the end of the
   week.

&&

.DISCUSSION...
/Issued 214 AM MST Mon Nov 3 2025/

 - Meteorological Overview:
A progressive pattern continues across the Northern Rockies to start
the week, with a largely zonal flow undulating back and forth
between subtle ridging and troughing. Initial ridging today will
keep much of the day dry, though weak troughing and Pacific moisture
begin to work in toward the late afternoon. Areas along the Rocky
Mountain Front are most favored for accumulating precipitation
tonight through Tuesday. A strong temperature gradient aloft will
result in widely varying snow levels for this system, lowest across
the Northern Rocky Mountain Front and highest in Southwest Montana.
Impacts at pass level largely look to be confined to Marias Pass
with this system. That said, the wetter type of snow combined with
roadways not immediately receptive to snow accumulation limits
confidence in travel impacts beyond visibility reductions near
Marias Pass east of the Continental Divide at this time.

As alluded to a bit with the snow level mention, temperatures across
Southwest Montana will be on the mild side to open up the week. As
brief upper ridging builds back in toward Wednesday, these milder
temperatures spread further north onto the plains as well. Although
ridging will be building in briefly for Wednesday, the continued
progressive nature to the pattern still does keep precipitation in
the forecast, mostly along the Continental Divide.

The active pattern continues Thursday through Saturday as two
slightly more robust waves moves across the region. Additional areas
of precipitation (Mainly along the Continental Divide) will
accompany these waves, along with at least one period of gusty
winds.

Ensemble means and cluster guidance favor upper level ridging
building in by Sunday. Uncertainty with the ridge is largely
associated with its east-west positioning. A further east ridge (25%
of scenarios) would result in a more southwesterly flow aloft (More
active), while a further west ridge (75% of scenarios) would support
more benign conditions. -AM

 - Forecast Confidence & Scenarios:
Rocky Mountain Front snowfall tonight into Tuesday:

Snow levels will support snow at Marias Pass and even down to lower
elevations adjacent to the Northern Rocky Mountain Front at times
when precipitation spills down to the plains. There is around a 40%
probability for 3 inches of snow at Marias Pass over 24 hours ending
5 PM Tuesday. Given the low confidence for impacts from this snow at
Marias Pass and adjacent areas further east, no Winter Weather
Advisory is being considered at this time. Should confidence
increase in impacts at and near Marias Pass, a Winter Weather
Advisory will be considered.

Snow looks to have a bit better success accumulating above passes
along the Northern Rocky Mountain Front. Areas above passes along
the immediate Continental Divide have around a 40% probability for 6
inches of snow. Those with recreation plans in this area should plan
for the cold/raw conditions.

Wind Tuesday across Southwest MT and vicinity:

Westerly to southwesterly flow increases across Southwest Montana
and vicinity tonight into Tuesday. The probability for a 40 mph gust
Tuesday in Dillon and Bozeman is 25% and 35% respectively.

Winds late week:

A few breezy days are forecast Thursday through Saturday as a couple
more impressive shortwaves traverse the Northern Rockies.
Probabilistic guidance favors Thursday as the day for the most
widespread winds along and north of I-90, with most non-wind
protected areas having greater than a 40% probability for a 50 mph
wind gust. -AM

&&

.AVIATION...
03/12Z TAF Period

Expect cloud cover over the CWA through the period. Ceilings will
gradually lower in most areas overnight tonight, as light
rain/snow showers develop over the Plains. The precipitation will
gradually work its way from north to south through the CWA
overnight. Do expect a bit heavier precipitation right along the
divide though. Some mountains/passes will be obscured along the
divide through the period because of clouds/precip. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  49  37  50  32 /  10  40  30   0
CTB  43  27  45  25 /  30  40  20   0
HLN  51  37  54  36 /  10  50  40  10
BZN  54  36  57  35 /   0  20  30  20
WYS  52  31  46  30 /   0  10  40  30
DLN  58  38  55  36 /   0  10  10  10
HVR  50  30  49  23 /  10  40  20   0
LWT  50  35  52  29 /   0  20  30  10

&&

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

&&

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