Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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309 FXUS65 KTFX 281730 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1030 AM MST Fri Nov 28 2025 Aviation Section Updated. .KEY MESSAGES... -Widespread snowfall continues today, bringing reduced visibility and slick roadways to North Central and Southwestern Montana. -Coldest air of the season surges into the area today, with subzero lows expected tonight and tomorrow night. -Another round of snowfall expected around Tuesday and Wednesday, but snowfall is likely to be light. && .UPDATE... /Issued 842 AM MST Fri Nov 28 2025/ Snow has expanded to areas as far south as Bozeman so far this morning with the colder airmass boundary already having pushed as far south as Boulder and Toston by 8am. Northerly winds with gusts in excess of 30 mph are occurring from the Rocky Mtn Front east to around I-15 across north-central MT as cold surface high pressure surges south along the east slopes of the Rockies. Winter storm event forecast is largely on track with minimal changes this morning except to adjust winds up a bit more in line with observations and adjust pops/timing to align with observed trends and incoming hi-resolution model data. With snow already occurring in areas along the I-90 corridor and at least a couple of inches expected as the stronger northerly winds push south into areas from Whitehall east to Three Forks this afternoon, have added a winter weather advisory for these areas as well for this afternoon through early this evening. Hoenisch && .DISCUSSION... /Issued 842 AM MST Fri Nov 28 2025/ - Meteorological Overview: An upper level trough will continue to push through the Northern Rockies today, bringing widespread snowfall and will usher in the coldest air of the season thus far in its wake. Snowfall this morning is generally confined to a band south of US 2 and north of US 87/89, but will shift southward and expand as cold air continues to surge southward and as the axis of the upper level trough moves overhead. Snow will generally be light to moderate, but a few areas of heavier snowfall will be possible, particularly along the cold front that will push through southwestern Montana today. Winds will also be elevated, particularly across the plains and in some of the north/south oriented valleys of Southwestern Montana, but the wet nature of the snow should prevent widespread blowing snow issues. Behind this system, surface high pressure will build into the area, which will bring with it the coldest air of the season thus far, with lows dipping below 0 for some, especially across the plains, with daytime highs reaching the low 20s for most except the most northern areas. This arctic high pressure system will shift to the east early next week, which will allow warmer air to work into the area from the southwest as it pulls away. As warmer air works into the area, upper level ridging will briefly work into the area next week, keeping our weather more tranquil, at least for a day before the ridge breaks down as another system dives in from the north. As it does, expect some widespread snowfall across the area, though at the moment it appears more likely than not that most areas will see just a light snow event with this system. Another high pressure system will follow this disturbance, which will bring with it another round of colder than average (but not arctic) temperatures to the area for the second half of the week. - Forecast Confidence & Scenarios: Snowfall today: For the most part, snowfall today will be a steady light snowfall across the plains, though a few areas of heavier snowfall will be possible as evidenced by the early morning presence of a snowfall band just north of Great Falls that should move southward through the day. Across Southwestern Montana, a few embedded heavier snow showers may be possible, so anyone traveling today should be prepared for some changing weather and road conditions. In addition to the falling snow, a few localized areas of blowing snow will also be possible today across the plains as winds gust to 30-35 mph. Blowing snow is less likely to be an issue early in the day thanks to low/wet snow ratios, but as snow ratios increase some blowing/drifting of the snow will be possible. Snowfall next week: Snowfall next week is likely to be a bit lighter than the ongoing snowfall event, though a few ensemble members across the suite of models do show a very low chance for some more significant snowfall in excess of 6-8 inches across the plains. While this appears to only have a 5-10% chance of materializing, it is worth keeping an eye on for more significant impacts. Ludwig && .AVIATION... 28/18Z TAF Period During the first 6 hours of this TAF Period there will be widespread snow which will reduce visibility to at least IFR-levels and at most terminals to LIFR-levels. After 29/02Z at most of the terminals the snow will begin to diminish and visibility will improve. However at the KHVR, KLWT, and KGTF terminals at least MVFR-level ceilings will remain for much of the rest of the TAF Period. There will be gusty winds during the first 6 hours of this TAF Period which will lead to some blowing snow at all terminals. During the duration of this TAF Period there will be mountain obscuration across North-central, Central, and Southwestern Montana. -IG && .PRELIMINARY POINT TEMPS/POPS... GTF 18 1 21 -4 / 90 60 0 0 CTB 14 -9 12 -9 / 80 0 0 0 HLN 26 1 22 5 / 90 20 0 10 BZN 33 -3 23 3 / 90 60 0 10 WYS 36 -4 24 6 / 80 60 0 10 DLN 40 4 27 12 / 70 20 0 0 HVR 20 -6 9 -16 / 90 80 0 0 LWT 21 -1 20 -1 / 90 80 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 11 PM MST this evening for Cascade County below 5000ft-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Southern High Plains-Southern Rocky Mountain Front-Western and Central Chouteau County. Winter Storm Warning until 5 AM MST Saturday for Bears Paw Mountains and Southern Blaine-Fergus County below 4500ft-Hill County-Northern Blaine County. Winter Weather Advisory until 5 AM MST Saturday for Big Belt, Bridger and Castle Mountains-Elkhorn and Boulder Mountains- Gallatin Valley-Gates of the Mountains-Helena Valley-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains- Madison River Valley-Meagher County Valleys-Snowy and Judith Mountains. Winter Storm Warning until 5 PM MST this afternoon for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains. Winter Weather Advisory until 5 PM MST this afternoon for Upper Blackfoot and MacDonald Pass. Winter Weather Advisory until 8 PM MST this evening for Canyon Ferry Area-Gallatin and Madison County Mountains and Centennial Mountains-Missouri Headwaters. && $$ http://www.weather.gov/greatfalls