Helena Valley Northeast, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

739
FXUS65 KTFX 060520
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1020 PM MST Fri Dec 5 2025

Aviation Section Updated.

.KEY MESSAGES...

 - This afternoon through Saturday there will be light snow across
   portions of the lower-elevations of North-central, Central, and
   Southwestern Montana and heavy snow across the mountains.

 - On Saturday it will briefly cool down across North-central
   Montana before warming up on Sunday.

 - Monday through Thursday it will be warm and windy with
   precipitation chances.

&&

.UPDATE...
/Issued 548 PM MST Fri Dec 5 2025/

A band of mainly snow is developing across western portions of
the region early this evening associated with a strong upper jet
and related forcing. This band will continue eastward through the
night, with snow showers developing behind the band, mainly along
the Continental Divide and into Southwest Montana. Strong mid
level flow moving in across Southwest Montana will result in
periods of gusty winds near and above pass level, especially near
snow shower activity through the overnight.

The only change this evening was to add the MacDonald Pass/Lincoln
area to the Winter Weather Advisory through the morning Saturday.
The combination of at least a few inches of snow from snow shower
activity along with gusty winds at times looks to pose at least
minor impacts to travel tonight. -AM

&&

.DISCUSSION...
/Issued 548 PM MST Fri Dec 5 2025/

 - Meteorological Overview:

This afternoon there is northwest flow aloft over North-central,
Central, and Southwestern Montana which will keep temperatures cool
this afternoon with mountain snow. Early this evening through
tonight an Arctic Cold front will move south from Canada. This
combined with warm air advection overriding the front will produce
a band of snow across North-central Montana along and north of a
Cut Bank to Lewistown line. Prior to the snow band forming there
is the potential for rainfall before it changes to all snow. There
will be a brief burst of heavy snowfall associated with the snow
band as it moves to the northeast this evening. On Saturday
northwest flow will remain over North-central, Central, and
Southwestern Montana. This combined with the cold front that moved
through will bring cold temperatures to North-central Montana on
Saturday. Snow will linger across the mountains and portions of
the lower-elevations of North-central, Central, and Southwestern
Montana on Saturday.

On Sunday an upper-level ridge will move over North-central,
Central, and Southwestern Montana. This will bring warmer
temperatures and mostly dry weather to the lower-elevation
locations of the area. There will be some light snow in Hill and
Blaine Counties Sunday morning. The upper-level ridge will remain
over North-central, Central, and Southwestern Montana on Monday
which will allow temperatures to warm up some more with dry
weather at lower-elevations and mountain snow. Due to an
increasing pressure gradient combined with strong mid- and low-
level winds, winds will begin to increase Monday afternoon and
evening. On Tuesday the upper-level ridge flattens before another
upper-level ridge builds in Tuesday afternoon. This will bring
precipitation chances and windy conditons to North-central,
Central, and Southwestern Montana on Tuesday. On Wednesday the
upper-level ridge remains over North-central, Central, and
Southwestern Montana this will allow the warm temperatures to
continue. Wednesday evening an upper-level shortwave will move
through and bring precipitation chances to the area with windy
conditions. On Thursday there is an upper-level trough over North-
central, Central, and Southwestern Montana. This will bring
cooler temperatures, precipitation chances, and windy conditions
to the area on Thursday. -IG

 - Forecast Confidence & Scenarios:

Tonight through Saturday morning there is greater than a 60% chance
for an inch of snow or greater along and north of a Cut Bank to
Lewistown line. From this evening through Saturday night there is
greater than a 60% chance for 6 inches of snow or greater along the
Rocky Mountain Front. As a result the Winter Storm Watch was
upgraded to a Winter Weather Advisory. See the TFX
WATCHES/WARNINGS/ADVISORIES section below for details.

On Monday there is greater than a 60% chance for wind gusts of 55
mph or greater along the plains west of I-15. On Monday and Tuesday
along the Rocky Mountain Front there is greater than a 60% chance
for wind gusts of 75 mph or greater. On Tuesday there is greater
than a 50% chance for wind gusts of 55 mph or greater across most
of North-central, Central, and Southwestern Montana. High wind
highlights were not issued at this time but there is a high chance
they will be issued in an upcoming shift.

On Tuesday and Thursday there is greater than a 50% chance for high
temperatures of 45 degrees or greater across most of the lower-
elevations of North-central, Central, and Southwestern Montana. On
Wednesday there is greater than a 40% chance for high temperatures
of 45 degrees or greater across most of the lower-elevations of
North-central, Central, and Southwestern Montana. From 5 PM Monday
to 5 PM Thursday there is greater than a 50% chance for 6 inches of
snow or greater across the mountains of North-central, Central, and
Southwestern Montana. IG

&&

.AVIATION...
06/06Z TAF Period

A band of snow continues to nudge eastward across the plains,
impacting KLWT and KHVR through the overnight. Meanwhile, snow
showers continue to stream across the Continental Divide. Southwest
MT terminals have the greatest probability to see these snow
showers into Saturday morning.

Increasing mid level westerly flow will yield a LLWS threat through
the remainder of the overnight across Southwest Montana and portions
of Central Montana.

A cold front looks to move south from Canada through the overnight,
which will result in low clouds that linger into at least the late
morning hours Saturday over the plains. -AM

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  16  23  22  41 /  90  60  10   0
CTB   7  16  13  38 /  80  20  10   0
HLN  30  40  28  42 /  90  70  30  10
BZN  28  39  22  40 /  90  70  30  10
WYS  20  32  14  29 / 100  80  50  50
DLN  28  40  23  38 /  80  30  10   0
HVR   9  14   7  31 /  90  60  60   0
LWT  15  26  21  39 /  90  70  40   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 9 PM MST Saturday for East Glacier
Park Region-Southern Rocky Mountain Front.

Winter Weather Advisory until 11 AM MST Saturday for Bears Paw
Mountains and Southern Blaine-Eastern Toole and Liberty-Elkhorn
and Boulder Mountains-Fergus County below 4500ft-Hill County-
Northern Blaine County-Snowy and Judith Mountains-Upper
Blackfoot and MacDonald Pass-Western and Central Chouteau County.

Winter Storm Warning until 2 PM MST Saturday for Big Belt,
Bridger and Castle Mountains-Gallatin and Madison County
Mountains and Centennial Mountains-Little Belt and Highwood
Mountains.

Winter Storm Warning until 5 PM MST Saturday for Northwest
Beaverhead County.

&&

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