Area Forecast Discussion
Issued by NWS Great Falls, MT

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
802
FXUS65 KTFX 301042
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
342 AM MST Sun Nov 30 2025

.KEY MESSAGES...

 - Freezing fog will result in some icy roads this morning across
   the Golden Triangle.
 - Areas of blowing snow will be possible on Monday as westerly
   winds increase.
 - Two more rounds of widespread snowfall are expected this week,
   the first on Tuesday and the second Friday and Saturday.

&&

.DISCUSSION...

 - Meteorological Overview:

An area of high pressure centered over Northeastern Montana this
morning will continue to shift to the southeast today. This will
allow, after a cold and foggy morning (particularly across the
Golden Triangle), warmer air to begin to work its way into the
area from the southwest. While areas north and east of a line from
Cut Bank to Fort Benton to the Missouri River Breaks will remain
trapped in the cold air today, even these areas will see
temperatures moderate on Monday.

Speaking of Monday, upper level ridging will begin to push into
the area on Monday, which will result in some gusty winds across
the plains and a few snow showers over the higher terrain of
Southwestern Montana as warmer air pushes into the area. However,
this ridging will not last long as a shortwave trough will push in
from the northwest on Tuesday, bringing some more widespread
snowfall to the area followed by another surge of colder air,
though not nearly as cold as the air mass currently over the area.


The second half of the week will be similar to the first half,
with a day or two of quieter weather conditions as a weak upper
level ridge builds into the area before a disturbance pushes in
from the Northwest on Friday. However, this Friday system does
have the chance to be a little more disruptive than the Tuesday
system since it might have some more moisture to work with, but
there still seems to be some disagreement on just how much
moisture this system will bring to the area. Beyond Friday and
Saturday, models continue to hint towards a larger scale pattern
change, which is likely to result in a period of cooler and
unsettled weather next week.

 - Forecast Confidence & Scenarios:

Blowing Snow Monday: As upper level ridging builds into the area
on Monday, winds across the plains are very likely to increase,
which could result in some blowing and drifting of the snowpack
across the area. However, there are a few areas of uncertainty at
this point with regards to how big of an issue any blowing or
drifting could be, including how much the snowpack compacts and
settles today and how quickly (or if) temperatures rise above
freezing, which would also put an end to any blowing or drifting
snow. However, as it stands the snowpack is not overly deep, so
any blowing snow is unlikely to be an issue for more than a few
hours before most of the snow is deposited into drifts.

Late week snow: While the arrival of some snowfall Friday and
Saturday is appearing more and more likely, there remains some
uncertainty as to how much snow will fall and how widespread an
area the snow will affect. Right now the most likely scenario
appears to be a quick hitting snowfall that drops anywhere between
1-4 inches across the lower elevations, but I cant rule out a
scenario where northerly winds behind this system bring some more
snow to the northerly upslope areas. Ludwig

&&

.AVIATION...
30/06Z TAF Period

While VFR conditions are expected to prevail across North Central
and Southwestern Montana this evening, there are a few areas of
concern overnight tonight. First will be a possible area of fog
and/or low stratus across the Golden Triangle (KCTB, KHVR, KGTF)
that seems to be in the beginning stages of development. There
will also be a few light snow showers south of Interstate 90, but
any reductions in vis and/or ceilings here will be short lived.
Ludwig

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  24  10  34  27 /   0   0   0  30
CTB  20   8  31  22 /   0   0   0  30
HLN  26  12  35  25 /   0   0   0  30
BZN  24   5  32  21 /   0   0   0  30
WYS  29   2  25  14 /  10   0  10  50
DLN  29  12  36  23 /   0   0   0  20
HVR   6  -6  28  18 /   0   0   0  30
LWT  26   8  35  22 /   0   0   0  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Freezing Fog Advisory until 9 AM MST this morning for Cascade
County below 5000ft-Eastern Glacier, Western Toole, and Central
Pondera-Eastern Pondera and Eastern Teton-Eastern Toole and
Liberty-Hill County-Western and Central Chouteau County.

Cold Weather Advisory until 10 AM MST Monday for Hill County-
Northern Blaine County.

&&

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