textproduct: Great Falls

KEY MESSAGES

- Thursday through Sunday there will be periods of light snow across North-central, Central, and Southwestern Montana.

- Today through Friday it will gradually cool down each day to have well-below seasonal average temperatures on Thursday and Friday.

- It will begin to warm back up Sunday through early next week.

DISCUSSION

/Issued 235 PM MST Wed Jan 21 2026/

- Meteorological Overview:

This afternoon there is northwesterly flow aloft which will cool down temperatures to around seasonal averages with dry conditions. On Thursday a surface high slides south from Canada into North Dakota. This combined with northwest flow aloft will pull some cold air from Canada into North-central, Central, and Southwestern Montana. The coldest temperatures will be in Hill and Blaine County. On Thursday associated with the southward progression of the surface high there will be light snow across portions of North-central, Central, and Southwestern Montana with the highest amounts in the mountains. On Friday northwest flow aloft will remain over North-central, Central, and Southwestern Montana. This will keep the cold and mostly dry conditions over the area.

On Saturday the northwest flow aloft over North-central, Central, and Southwestern Montana will remain, but the cold air will begin to slowly move out of the area. On Saturday there will be isolated mountain snow across the area. On Sunday an upper-level ridge will begin to move over North-central, Central, and Southwestern Montana. This will allow temperatures to warm up with mostly dry weather. On Monday and Tuesday the upper-level ridge remains over North-central, Central, and Southwestern Montana. On Monday and Tuesday it will also be windy across North-central, Central, and Southwestern Montana. This will allow temperatures to warm up further with dry weather. -IG

- Forecast Confidence & Scenarios:

On Thursday morning there is greater than a 50% chance for low temperatures below zero along most of the Hi-Line. Temperatures on Friday across North-central Montana remain uncertain at this time. The deterministic NBM MinT and NBM MaxT were warmer than the 50th Percentile NBM MaxT and the 50th Percentile NBM MinT. Temperatures were lowered across North-central Montana to be closer to the NBM 50th Percentile. On Friday morning there is a 25 - 50% chance for low temperatures of 20 below zero across Hill and Northern Blaine Counties. Elsewhere across North-central Montana there is greater than a 50% chance for low temperatures of 10 below zero Friday morning. As a result an Extreme Cold Watch was issued for Hill and Blaine Counties for Thursday evening into Friday morning. -IG

AVIATION

22/00Z TAF Period

The primary concern this TAF period will be for north to northeast winds developing over the plains this evening and tonight, moving into Southwest Montana into Thursday. Low clouds will accompany this shift in winds, though confidence in widespread sub-VFR is not high at this time. Mountain obscuration will increase tonight and persist through the day Thursday. -AM

PRELIMINARY POINT TEMPS/POPS

GTF 9 18 -5 8 / 0 10 20 10 CTB 4 13 -9 7 / 0 10 10 0 HLN 11 22 1 12 / 0 0 10 10 BZN 6 24 0 13 / 0 0 10 10 WYS -6 24 -6 18 / 0 0 0 20 DLN 12 28 6 18 / 0 0 0 0 HVR 4 9 -15 1 / 0 0 10 0 LWT 5 13 -8 5 / 0 10 40 20

TFX WATCHES/WARNINGS/ADVISORIES

Extreme Cold Watch from Thursday evening through Friday morning for Bears Paw Mountains and Southern Blaine-Hill County-Northern Blaine County.