758
FXUS65 KTFX 071512
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
812 AM MST Sun Dec 7 2025

.KEY MESSAGES...

- Daily snowfall is expected in the mountains, with light snowfall
  possible mid week at lower elevations.

- Cold air will retreat northward today, but move back south
  later this week.

- Strong winds likely Monday into Tuesday.

&&

.UPDATE...

Today it will be warm across most of North-central, Central, and
Southwestern Montana with a round of light precipitation that
will affect some areas this afternoon through this evening. Across
the Hi-Line and Hill and Blaine Counties in particular the Arctic
air will linger through most of the day today. For the update,
temperatures across Hill and Blaine County were decreased to
better reflect current observations and trends. The rest of the
forecast is on track. -IG

&&

.DISCUSSION...
/Issued 425 AM MST Sun Dec 7 2025/

 - Meteorological Overview:
Expect the weather pattern to generally change every few days over
the CWA, as cold air moves north/southward this week, along with
periods of snow.

As of 3 AM this morning, the warm front was now along a line from
Cut Bank to Carter to Lewistown, and slowly moving northward. This
warm front should move into the northern portions of Hill/Blaine
counties by this evening. Some scattered light snow showers are
falling along the divide, but downslope winds east of the divide
are limiting how far the precip is moving off the mountains.

Thus, expect above normal temperatures over much of the CWA today,
as warmer air continues to move in from the south.

On Monday, a strong area of low pressure will start to move from
west to east across southern Canada. This will result in the
potential for strong winds to develop along the front range of the
Rockies by late Monday afternoon. The strong winds will then move
eastward over the Plains Monday night, and exit the area on
Tuesday morning. Overall, the timing is not great for mixing down
the strong winds, however, the potential is there. Thus a high
wind watch was issued for much of North Central MT. Above normal
temperatures are expected once again on Monday.

On Tuesday, the strong winds will diminish in the morning, as
surface winds switch around to the north. After Tue morning, the
forecast models start to differ on how far/fast the cold air will
move south. The GFS model is the most aggressive and likely the
coldest model. Since the cold air is not going to go very far
north of MT on Monday, this is a reasonable solution. As of now
though, the NBM does not bring in the colder air until Wed.

For Thur/Fri...expect generally below normal temperatures across
the CWA...with the potential for cold weather advisory conditions
along the US/Canadian border. Additionally, periods of snow at
all elevations are possible. At this time, snow amounts look light
at low elevations, but with the northerly upslope, some areas
could see a bit heavier snowfall than currently forecasted.

For next weekend, the forecast models would like the cold air to
retreat northward once again. However, caution is urged in the
temperature forecast for next weekend, as sometimes the cold air
is quite slow to move out, and does not move out as quickly as the
forecast models like several days out.

Note...for the mountain areas of the Rocky Mountain Front,
Southwest MT and the Kings Hill area, there will be daily chances
for snowfall from Monday through Friday. When the cold air moves
south mid week, the snowfall could be heavy at times in the
mountains.

 - Forecast Confidence & Scenarios:

Winds:
The main concern for the high winds is if the strong winds aloft
will mix down during the overnight period Monday night into Tue
morning. The NBM probability of wind gusts over 60 mph has
increased to nearly 80 percent over the Plains and near 90 percent
along the Rocky Mountain Front. The chance for 75 mph wind gusts
along the Rocky Mountain Front is also near 80 percent in the
windier locations.

Snow:
Snow will be heavy at times in the mountains along the Rocky
Mountain Front, Southwest MT and the Kings Hill area. At this time
the heavy snow is mostly expected above pass level through Tuesday
morning, with lighter snowfalls around pass level. Thus the
current thinking is that a winter weather advisory might be needed
for a portion of this period. For Tue afternoon into Thu, snow
levels lower with the colder air moving in. Thus the potential for
heavy snow will also lower. It is possible a winter storm warning
might be needed later this week for some mountain ranges. By the
end of the week, lighter snowfall returns to the mountain ranges.

Overall, snowfall in the mountains above pass level could average
between 6 and 12 inches daily for some mountain ranges. At pass
level, several days of 2 to 5 inch snowfalls are likely. Thus
after several days of this type of snowfall, impacts will start to
develop.

Cold:
The cold air retreats today, but returns by mid week. By late in
the work week, it could be cold enough along and north of the
Highway 2 corridor from Browning to Harlem, that a cold weather
advisory might be needed for portions of this area. Brusda

&&

.AVIATION...
07/12Z TAF Period

Light snow showers will affect the Rocky Mountain Front today,
otherwise, most of the rest of the area, the snowfall has moved
off to our east. Some patchy fog could affect the Havre/Harlem
areas this morning before west winds start to increase. Otherwise,
the main concern will turn to the potential for strong surfaces
windiest developing over North Central MT late Monday afternoon
into Tue morning over much of North Central MT. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  42  35  48  41 /  10  20  10  30
CTB  36  27  42  33 /   0  10  10  40
HLN  43  32  47  39 /  20  30  20  50
BZN  40  27  45  36 /  10  20  10  30
WYS  28  21  33  26 /  60  70  60  80
DLN  40  29  44  37 /  10  20   0  30
HVR  32  25  42  30 /   0  10   0  40
LWT  40  28  43  32 /   0  20  10  30

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from Monday afternoon through Tuesday morning
for Cascade County below 5000ft-East Glacier Park Region-Eastern
Glacier, Western Toole, and Central Pondera-Eastern Pondera and
Eastern Teton-Eastern Toole and Liberty-Gates of the Mountains-
Northern High Plains-Southern High Plains-Southern Rocky
Mountain Front-Upper Blackfoot and MacDonald Pass.

High Wind Watch from Monday evening through Tuesday morning for
Bears Paw Mountains and Southern Blaine-Big Belt, Bridger and
Castle Mountains-Fergus County below 4500ft-Hill County-Judith
Basin County and Judith Gap-Little Belt and Highwood Mountains-
Madison River Valley-Meagher County Valleys-Northern Blaine
County-Snowy and Judith Mountains-Western and Central Chouteau
County.

&&

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