textproduct: Great Falls

KEY MESSAGES

- Another system will bring widespread snowfall to the area tonight through early Wednesday morning.

- This afternoon through the end of the work week it will gradually warm up.

- Another system will move through Friday and Saturday and bring precipitation with details uncertain at this time.

DISCUSSION

/Issued 233 PM MST Mon Dec 1 2025/

- Meteorological Overview:

This afternoon there is an upper-level ridge over North-central, Central, and Southwestern Montana. This will allow temperatures to warm up with mostly dry weather. Due to the ridge building in over the area briefly combined with a strong surface pressure gradient it will be windy today. This will lead to some areas of localized blowing snow through this evening. Tonight an upper-level trough will move over North-central, Central, and Southwestern Montana. This will bring snow to North-central, Central, and Southwestern Montana. On Tuesday the upper-level trough remains over North- central, Central, and Southwestern Montana. As a result the snow will be off and on through early Wednesday morning with cool temperatures.

On Wednesday the upper-level trough remains over North-central, Central, and Southwestern Montana. This will slightly cool down temperatures with mostly dry weather. On Thursday an upper-level ridge builds in over North-central, Central, and Southwestern Montana this will allow temperatures to warm up with mostly dry weather. Friday through Saturday there will be northwest flow aloft which will cool down temperatures slightly and bring precipitation to North-central, Central, and Southwestern Montana. On Sunday an upper-level ridge will move over North-central, Central, and Southwestern Montana. This will bring warmer temperatures and dry weather to the area. IG

- Forecast Confidence & Scenarios:

Tonight through Wednesday morning there is greater than a 65% chance for 2 inches of snow or greater along the Montana 200/US Highway 87 Corridor between Great Falls and Lewistown. Across the mountains of North-central, Central, and Southwestern Montana there is greater than a 50% chance for 6 inches of snow or greater.

For Friday into Saturday there is high uncertainty in the upper- level pattern. For Friday into Saturday half of the clusters keep an upper-level ridge over North-central, Central, and Southwestern Montana. While the other half of the clusters have an upper-level ridge to the west of Montana with northwest flow aloft. The northwest flow aloft scenario would bring colder temperatures and more precipitation to North-central, Central, and Southwestern Montana. The upper-level ridge scenario would keep warm temperatures with mostly dry weather across the area. IG

AVIATION

02/00Z TAF Period

A series of weather disturbances moving through northwest flow aloft will bring lowering cloud-bases and increasing mountain obscuration this evening as areas of snow develop. A period of snow and MVFR/IFR conditions will affect some southwest MT terminals later this evening and overnight with MVFR conditions becoming more widespread at most terminals later tonight through Tuesday. Hoenisch

PRELIMINARY POINT TEMPS/POPS

GTF 28 35 16 33 / 70 90 60 0 CTB 24 33 9 30 / 60 80 30 0 HLN 25 34 16 32 / 60 80 50 0 BZN 21 34 15 32 / 60 80 40 0 WYS 15 28 5 28 / 70 90 40 0 DLN 23 37 15 33 / 40 50 40 0 HVR 19 35 5 25 / 50 70 30 10 LWT 23 33 11 32 / 60 90 70 10

TFX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 11 PM MST Tuesday for East Glacier Park Region-Northwest Beaverhead County-Southern Rocky Mountain Front.

Winter Weather Advisory from 5 AM Tuesday to 5 AM MST Wednesday for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft-Fergus County below 4500ft-Gates of the Mountains-Helena Valley-Judith Basin County and Judith Gap-Upper Blackfoot and MacDonald Pass.

Winter Weather Advisory from 11 PM this evening to 5 AM MST Wednesday for Big Belt, Bridger and Castle Mountains-Gallatin and Madison County Mountains and Centennial Mountains-Little Belt and Highwood Mountains-Snowy and Judith Mountains.