textproduct: Great Falls

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.