textproduct: Great Falls

KEY MESSAGES

- A round of snow develops today, lasting into early Sunday.

- Trending milder heading into next week.

- Breezy at times late weekend through much of next week.

UPDATE

Today there will be light snow across portions of North-central, Central, and Southwestern Montana. The heaviest snowfall will be in the Little Belts and Snowies. For lower-elevation locations the heaviest snow will be between Belt and Geyser. With winds increasing today, there will be blowing snow at times in some areas. With the update, Winter Weather Advisories where considered for the Helena and Gallatin valleys. However even if models underperform snow amounts in those areas will remain below 2 inches so a Winter Weather Advisory wasn't issued at this time. A Winter Weather Advisory was also considered for 191 south of the Gallatin Valley. But given that only one small stretch of that road will get 3 inches, a Winter Weather Advisory wasn't issued at this time. The current Winter Weather Advisories handle the current situation well. For the update, high temperatures across North-central Montana were lowered to reflect current observations and trends. Pops across North-central Montana were increased through Sunday morning to better reflect current hi-res model guidance and the current radar imagery. QPF across North- central Montana was increased to better reflect the latest hi-res model guidance and due to this event being northwest flow which models struggle to handle. The rest of the forecast is on track. -IG

DISCUSSION

/Issued 446 AM MST Sat Jan 24 2026/

- Meteorological Overview:

A modest but weakening upper level jet with mid level shortwave will progress southward within a cyclonic northerly flow aloft through the day today into tonight across the region. The result will initially be for increased cloud cover early this morning before better forcing arrives through the day. As the better support arrives through the day, mainly light snow will develop across much of the region. Areas that look to see greatest impacts from snow will be between Great Falls and Lewistown, including the northerly upslope regions in the Little Belts. The northern portions of the Gallatin and Madison ranges also look to get in on accumulating snowfall later in the day today into tonight. Snow gradually diminishes late tonight and early Sunday as upper level support wanes.

As the aforementioned system departs tonight, clearing skies toward daybreak across the Hi-Line will foster temperatures once again dropping below zero. Southerly to southwesterly winds developing through the day Sunday will help moderate most areas, though areas near and east of Havre look to hang on to the colder temperatures for at least another day. A strengthening pressure gradient along the Rocky Mountain Front Sunday evening will look to develop a period of breezy winds into Monday morning. Although these winds do not look to be overly strong, temperatures remaining below freezing in this area will allow for any snow that does fall today into tonight to drift at the very least.

Upper level ridging develops, and largely looks to persist through much of next week. A continued moderating trend into early next week is forecast, with dry conditions favored. Weak waves cascading down the east side of the ridge may promote light precipitation at times, but the timing and location of any specific wave is very low confidence at this time. -AM

- Forecast Confidence & Scenarios:

Snow Today and Tonight:

Northerly upslope areas, including the Little Belts, Snowies, and the northern end of the Madisons and Gallatins look to be most favored for snow today into tonight. Forcing for ascent elsewhere looks to be a bit more nebulous and more brief in nature, which will help keep snowfall amounts a bit lower. The probability for 3 inches of snow is highest in the Little Belts and west end of the Snowies, sitting between 50 and 80%.

Rocky Mountain Front wind and potential for blowing snow:

Northerly flow aloft is usually not the most conducive setup for breezy winds along the Rocky Mountain Front, but near the surface a pressure gradient looks to develop late afternoon Sunday into Sunday night. Latest in-house guidance suggests the pressure difference between Kalispell and Cut Bank will peak between 10 and 15mb Sunday evening or Sunday night. Sustained westerly to southwesterly winds along the Northern Rocky Mountain Front will increase as a result, and be sufficient (combined with temperatures that remain below freezing) to at the very least drift any existing relatively fresh snowpack. Blowing of snow is not out of the question, and will ultimately depend on just how much snow falls today and tonight along the Rocky Mountain Front. 25th percentile sustained wind (75% chance for a stronger sustained wind) is around 25 mph along the Rocky Mountain Front Sunday evening through Monday morning.

Ridging next week:

Cluster guidance and associated ensembles are essentially unanimous in a period of upper level ridging being in place through the upcoming work week. Small embedded features within the ridging will promote very low-end precipitation opportunities at times next week, but the main takeaway is for another period of drier conditions with near to above average temperatures heading into the end of January. -AM

AVIATION

24/12Z TAF Period

Areas of light snow, gusty northwesterly winds, and associated low VFR/MVFR/IFR conditions develop from north to south today in response to an approaching shortwave embedded within a cold northwesterly flow aloft. The worst conditions will be over and near the north/northwest oriented foothills of the central island ranges. Another subtle shortwave moves in tonight and maintains the periods of light snow and degraded flight categories. - RCG

PRELIMINARY POINT TEMPS/POPS

GTF 19 -1 25 17 / 60 70 0 0 CTB 19 -6 26 16 / 60 40 0 0 HLN 21 3 24 10 / 50 60 0 0 BZN 20 4 22 3 / 50 60 10 0 WYS 17 -5 17 -9 / 40 50 10 0 DLN 27 7 26 8 / 10 30 10 0 HVR 12 -10 15 3 / 60 30 0 0 LWT 15 -8 20 7 / 70 80 10 0

TFX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 5 AM MST Sunday for Fergus County below 4500ft-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Snowy and Judith Mountains.