textproduct: Great Falls

KEY MESSAGES

- Light snowfall will continue this afternoon through Wednesday morning.

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

- Another system will move through Friday and Saturday and bring primarily mountain snow with gusty winds.

UPDATE

/Issued 753 PM MST Tue Dec 2 2025/

Only minor adjustments made this evening to the on-going forecast, with the main adjustment being to increase the areal coverage of patchy fog across the CWA given that surface observations were approaching 0 for dewpoint depressions and/or stations were reporting reduced visibility due to fog/mist. Additionally, the winter weather statements were updated to include mention of wet roads quickly refreezing through the evening hours. Otherwise the remainder of the forecast remains on track, with light to at times moderate snow persisting along and near the Montana Hwy 200 corridor across Central Montana for much of the overnight hours tonight. - Moldan

DISCUSSION

/Issued 753 PM MST Tue Dec 2 2025/

- Meteorological Overview:

This afternoon there is an upper-level trough over North-central, Central, and Southwestern Montana. This will bring light snow on and off this afternoon to North-central, Central, and Southwestern Montana. A cold front will move through the area this afternoon through this evening. This will bring another round of snow to the area. The snow will linger through early Wednesday morning with cold temperatures due to the cold front. 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 with northwest flow aloft this will allow temperatures to warm up some more with mostly dry weather. Friday through Saturday there will be northwest flow aloft which will cool down temperatures slightly and bring snow to Southwestern Montana and snow to the mountains of North-central and Central Montana. Friday evening into Saturday an upper-level shortwave trough will move through Southwestern Montana which will bring some strong winds to Southwestern Montana with the strongest winds in north-south oriented valleys.

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. 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 mostly dry weather. On next Tuesday the upper-level ridge begins to flatten which will bring windy conditons to the area on next Tuesday. -IG

- Forecast Confidence & Scenarios:

Due to observed snowfall in Fergus county combined with high confidence in additional snowfall exceeding warning criteria, a Winter Storm Warning was issued for Fergus County and it will continue through 5 AM Wednesday morning.

Friday through Saturday there is greater than a 70% chance for four inches of snow or greater across the mountains of North-central, Central, and Southwestern Montana. There is greater than a 70% chance for snowfall of 6 inches or greater along the Rocky Mountain Front Friday through Saturday. Winter weather highlights will be needed for this event but due to some details still needing to be resolved combined with the ongoing winter weather no highlights were issued at this time for Friday through Saturday. There is greater than a 30% chance for 1 inch of snow or greater Friday through Saturday across the lower-elevations of North- central, Central, and Southwestern Montana. However there is greater than a 50% chance for an inch of snow or greater across lower-elevation areas near/adjacent to mountains in Southwestern Montana Friday through Saturday.

Looking out towards the end of this forecast period there is high confidence in lower-elevation locations of North-central Montana approaching high temperatures of 50 degrees by the middle of next week. IG

AVIATION

03/06Z TAF Period

Snow winds down throughout the morning (from 03/08z through 03/25z). Snow will continue to bring MVFR/IFR conditions through the morning. Clouds clear out a bit Wednesday afternoon. Breezy winds settle in along the North-Central MT plains Wednesday evening. -Wilson

PRELIMINARY POINT TEMPS/POPS

GTF 17 32 23 37 / 60 10 0 20 CTB 9 30 21 34 / 40 10 0 10 HLN 17 32 21 36 / 70 10 0 40 BZN 15 30 13 35 / 50 10 0 40 WYS 5 29 10 25 / 60 0 20 80 DLN 15 33 18 36 / 50 10 0 10 HVR 4 25 10 34 / 30 10 0 20 LWT 13 32 18 36 / 100 20 0 20

TFX WATCHES/WARNINGS/ADVISORIES

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

Winter Weather Advisory until 5 AM MST Wednesday for Bears Paw Mountains and Southern Blaine-Big Belt, Bridger and Castle Mountains-Cascade County below 5000ft-Elkhorn and Boulder Mountains-Gallatin and Madison County Mountains and Centennial Mountains-Gates of the Mountains-Helena Valley-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Snowy and Judith Mountains-Upper Blackfoot and MacDonald Pass.

Winter Storm Warning until 5 AM MST Wednesday for Fergus County below 4500ft.