textproduct: Great Falls

KEY MESSAGES

- A series of weather disturbances will move across the region Tuesday and Wednesday bringing a chance for light snow across the region and gusty winds across central Montana.

- Cooler, but more seasonable, temperatures will linger through Saturday before gradually warming up again.

DISCUSSION

/Issued 251 PM MST Mon Jan 19 2026/

- Meteorological Overview:

A break in between weather disturbances will provide dry and less windy conditions to the area today before the next series of fast moving shortwaves in northerly flow aloft move across the area Tuesday and Wednesday. The first of these shortwave disturbances moves through Tuesday morning, shifting surface winds back to north/northwest as a weak surface low moves off to the southeast and high pressure builds south in its wake. The second shortwave looks to clip eastern MT Wednesday morning, followed by a renewed push of surface high pressure while the main push of colder air with both of these system remains well east of the area. The main impact from both of these waves will be a period of gusty north to northwest surface winds, primarily affecting the north-central MT plains. Some increase in moisture and shallow instability will support scattered snow showers with the wave passing Tuesday morning. The further east trajectory of Wednesday's disturbance is less favorable for snow showers, though a few flurries are possible.

Models continue to trend toward troughing across Canada remaining more consolidated and further east later this week, decreasing the risk for significant cold and snow across the area later this week into the weekend. There is still reasonable consensus for a period of colder temperatures as the trough elongates some and a cold 1050MB surface high slides south into the N-central US Thursday and Friday. Moisture however looks to be fairly limited with a much lower risk for widespread snowfall. Hoenisch

- Forecast Confidence & Scenarios:

Snow Tonight:

There is a chance for lower elevation snow during the overnight hours into late Tuesday morning. Lower elevation snowfall amounts are generally expected to stay below half an inch with some isolated higher amounts possible. Across the Little Belts, Bears Paw, and Snowies, 1 to 3 inches is the most likely with locally higher amounts possible along the highest peaks.

When assessing the threat level and the confidence in higher amounts, right now there are not any significant concerns for impacts at and below pass level. Pavement temperatures have remained relatively warm and it is expected that most, if not all, of the snow that falls on the roads will melt fairly quickly and cause little to no impact for commuters. As such, no Winter Weather Advisories will be issued with this update.

When looking for potential wild cards, Lewistown and the stretch of Highway 200 that passes in between the Little Belts and the Highwoods have the highest probability of seeing higher-than- currently-forecasted amounts. The hi-res models are not overly confident on either location seeing more than 2 inches but they still manage to put out a non-zero chance for snowfall amounts up to 4 inches. A lot of this comes from the possibility of some terrain-enhanced snowfall in those regions. But because confidence in those higher amounts is so low, there is not a good justification for issuing a Winter Weather Advisory for these locations at this time. That being said, these will be areas to watch as, should snowfall amounts over-perform from what is currently expected, the concerns for impacts may increase enough to warrant an advisory.

Wind Tuesday/Wednesday:

Breezy conditions are expected Tuesday and Wednesday along the Rocky Mountain Front as well as portions of central Montana including downwind of the Sweetgrass Hills, Bears Paw, Snowies and Judith mountains. While an occasional gust up to 50 mph is possible, the concerns for high winds is not enough to warrant a High Wind watch or warning at this time. -thor

AVIATION

20/00Z TAF Period

Primary concern this TAF period will be for a cold front moving south across the region late tonight into the day Tuesday. A quick round of light snow will accompany the front in many locations, with northerly upslope areas the most likely to see lingering snow and associated low vis/cigs. Otherwise, isolated instances of low- level wind shear in Southwest Montana valleys will be around tonight, but are too low confidence to include in any TAFs at this time. -AM

PRELIMINARY POINT TEMPS/POPS

GTF 26 35 20 30 / 10 40 0 0 CTB 22 33 15 26 / 10 20 0 0 HLN 24 35 18 31 / 0 30 0 0 BZN 19 34 12 29 / 0 20 0 0 WYS 5 27 0 27 / 0 20 0 0 DLN 21 37 14 34 / 0 0 0 0 HVR 21 30 13 24 / 10 30 0 0 LWT 22 33 15 27 / 0 60 0 0

TFX WATCHES/WARNINGS/ADVISORIES

None.