textproduct: Great Falls

KEY MESSAGES

- Areas of snow will continue today, with cold temperatures over the northern portions of North Central MT.

- Almost daily chances for mountain snow are expected Sunday through Friday, with a chance for lower elevation snow mid week.

- There is a high potential for strong winds over much of area Monday through Wednesday.

UPDATE

A moist WNW flow aloft remains in place this morning with a broad upper level frontal zone across the region while a sharper low level front has pushed as far south as the MT-200/US-87 corridor across central MT. To the north of the low level front temps have cooled to mostly to the teens with widespread low clouds and areas of fog, along with some light snow, primarily east of I-15. Fog is beginning to lift with the area of light snow expected to lift northeast through the rest of this morning. South of the low level front, precipitation is focused orographically with snow in the mountains and scattered rain/snow in the valleys, where temperatures are in the low/mid 30s this morning and rise to around 40 this afternoon. Temperatures across north-central MT are expected to remain steady in the teens and twenties through much of today but are likely to rise from west to east this evening and overnight as a warm front pushes across the area. Hoenisch

DISCUSSION

/Issued 437 AM MST Sat Dec 6 2025/

- Meteorological Overview: Overall, areas of light snow continue to affect portions of the CWA this morning. The heaviest snowfall is falling along the divide and across the mountains of Southwest MT, mostly in the West Yellowstone area. The snow is likely to continue into the evening hours in the West Yellowstone area, so that warning was extended a few hours. Otherwise, there no changes to the other current winter statements currently in effect for today.

One concern for today is how far south will the cold air make it. As of 3 AM, the cold air was generally north of a Dutton to Loma line. This cold air could sag a bit further south into the Great Falls area later this morning, before starting to shift back further north tonight. Additionally, areas of dense fog will also affect portions of North Central MT through Sunday morning.

For Sunday through Tuesday, strong southwesterly winds are forecast to develop over the CWA. This will result in some fairly mild air moving into the CWA at lower elevations for early next week. Additionally, there is a good potential that high wind statements will be needed come Monday night into Wed for much of the CWA.

Wednesday through next Saturday...Colder air will try to move southward Wed/Thu behind the storm system that produces all the wind. The main question is how far south does the cold air make it, and how fast does the cold air retreat late next week. A period of snow is likely Wed into Thu over much of the CWA along with some cold temperatures. However, on Friday, some models want the cold air to begin to retreat already, with a return of mild air by Saturday. This might be a bit too fast, but it is not out of the question either. So do expect some significant changes in daily temperatures late next week, with afternoon highs possibly being even warmer than currently forecasted.

- Forecast Confidence & Scenarios: The main concern for the next few days will be the wind potential Mon into Wed. Some models prog a strong wind event over portions of North Central MT. Right now, much of North Central MT has over a 60 percent chance for high winds on Tuesday, with the windy locations along the Rocky Mountain Front and in the Cut Bank area having over an 80 percent chance for high winds.

The second concern for late next week will be the timing of the return of the cold air, along with how far south does it go, and how fast does it retreat. The forecast models all vary on the details, thus confidence is on the low side right now on the daily details of how cold/snowy/how fast it will warm up for late next week. Brusda

AVIATION

06/12Z TAF Period

Main concerns today will be areas of dense fog over North Central MT and the light snow. Expect areas of dense fog through Sunday morning over North Central MT. It will be sporadic in terms of affecting terminals, but 1/4sm in dense fog will be possible for short periods of times as the fog moves in/out. Otherwise, light snow will also affect a good portion of the CWA today, especially the mountains. Overall the snow will begin to diminish in coverage area this evening. Mountains/passes will be obscured across the CWA through the period. Brusda

PRELIMINARY POINT TEMPS/POPS

GTF 31 20 41 35 / 60 10 0 10 CTB 27 11 37 29 / 20 10 0 0 HLN 40 28 41 31 / 80 30 10 20 BZN 39 23 39 27 / 80 40 10 20 WYS 34 14 29 21 / 80 40 50 80 DLN 41 25 38 28 / 40 10 0 20 HVR 14 7 35 24 / 70 70 0 10 LWT 33 20 38 27 / 70 50 0 10

TFX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 9 PM MST this evening for East Glacier Park Region-Southern Rocky Mountain Front.

Winter Weather Advisory until 11 AM MST this morning 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 this afternoon for Big Belt, Bridger and Castle Mountains-Little Belt and Highwood Mountains.

Winter Storm Warning until 9 PM MST this evening for Gallatin and Madison County Mountains and Centennial Mountains.

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