textproduct: Great Falls

KEY MESSAGES

- Gusty north to northwest winds and snow showers accompany a quick moving weather disturbance across north-central and central Montana this morning.

- Another period of gusty north winds is expected later tonight through Wednesday morning across north-central Montana with locally stronger winds near the island mountain ranges.

- A period of colder temperatures is likely Thursday and Friday with the coldest airmass affecting eastern portions of north- central Montana.

DISCUSSION

/Issued 408 AM MST Tue Jan 20 2026/

- Meteorological Overview:

The Northern Rockies and MT remain on the far SW periphery of a deep upper level trough centered near Hudson Bay through the remainder of the work week. The next clipper-type shortwave disturbance pivoting around the trough will move south across the area this morning, bringing a shift to gusty northwest winds and a period of snow showers as it quickly moves through the area. Low level cold advection and surface pressure rises will support gusts in the 30-40 mph range across much of north-central and central MT this morning with a few higher gusts near the island mountain ranges. Enough moisture and shallow instability (mostly below 700MB) will develop across north-centrla MT this morning to support the development of snow showers with enhanced coverage near the north slopes of central MT mountains, especially the Little Belts and Snowies.

Snow showers and winds will decrease this afternoon as the quick moving system exits the area with relatively dry and less windy conditions persisting through this evening before the next disturbance arrives later tonight. This system will have less moisture and a limited coverage of a few snow showers/flurries as it moves through early Wednesday morning, but potential for higher wind/gust speeds as an area of 45-50kt flow at 850-700mb moves across eastern portions of north-central MT, where a few gusts in excess of 50 mph area possible near the island mountain ranges.

Temperatures cool to near seasonal averages today with slight additional cooling on Wednesday. More noticeable cooling is expected Thursday and Friday as a strong surface high shifts from the Canadian Prairies south through the Dakotas. The coldest of this airmass remains east of the area but temperatures will fall below seasonal averages with the coldest temperatures on the plains. Some warming is likely this weekend as the upper level pattern de-amplifies some and the Canadian trough shifts east, but the area is likely to remain under a northwest flow aloft with some uncertainty in the potential for additional disturbances to move through by then. Hoenisch

- Forecast Confidence & Scenarios:

Snowfall amounts in excess of 2 inches are likely (>70% probability) across the Little Belts and Snowies this morning. Weakly unstable northerly flow will favor some enhancement along and adjacent to the north slopes of these ranges with some potential for a period of more widespread snow showers across Judith Basin and Fergus Counties this morning, where localized accumulation to around 1" is possible. While snowfall amounts are fairly low, gusty winds will occur with the snow showers and may may briefly impact areas along US-87 from Belt east to Lewistown this morning with locally reduced visibility. Hoenisch

AVIATION

20/12Z TAF Period

Gusty north winds develop from north to south this morning as a fast moving weather disturbance moves through the region. Lower clouds and areas of snow showers spread across north-central MT this morning with a period of MVFR cloud cigs and potential for snow showers as far south as KBZN. KLWT will see a more persistent period of snow showers with potential IFR conditions this morning. Low clouds ceilings will improve this afternoon as the system exits with gusty north winds decreasing later this afternoon into this evening. Hoenisch

PRELIMINARY POINT TEMPS/POPS

GTF 35 20 30 10 / 50 10 0 0 CTB 32 16 26 4 / 30 0 0 0 HLN 34 17 31 11 / 50 0 0 0 BZN 32 12 30 10 / 20 0 0 0 WYS 26 -1 27 -3 / 20 0 0 0 DLN 35 13 35 14 / 0 0 0 0 HVR 30 13 24 2 / 30 0 0 0 LWT 32 15 26 6 / 80 0 0 0

TFX WATCHES/WARNINGS/ADVISORIES

None.