textproduct: Great Falls

KEY MESSAGES

- Gusty north to northwest winds this morning with a few localized stronger gusts across eastern portions of north- central Montana.

- Another period of gusty north to northwest winds is likely Tuesday and Wednesday with a few snow showers possible.

- A turn to much colder temperatures and increased risk for snowfall will develop late this week into the weekend.

DISCUSSION

/Issued 409 AM MST Sun Jan 18 2026/

- Meteorological Overview:

The Northern Rockies and MT remain under a fast northerly flow aloft through most of the upcoming work week, situated in between a high amplitude upper level ridge with axis offshore of the west coast while troughing broadens across central/eastern Canada. Surface high pressure is building south into the area this morning in the wake of a mid-level wave dropping south through eastern MT and the Dakotas. A period of gusty north to northwest surface winds will accompany the surge of high pressure across the plains this morning with any gusts in excess of 40 mph limited to eastern portions of north- central MT. Clouds within a fairly shallow layer of moisture around 700MB will expand south into northern portions of southwest MT by this afternoon as the deeper northerly flow overspreads the area. While a few flurries/snow showers are possible near the central MT mountain ranges today, the relatively shallow depth of moisture and instability will keep precipitation limited.

Dry and less windy conditions are expected Monday before the next series of waves track south through the area Tuesday and Wednesday. Another round of gusty north to northwest winds will accompany these disturbances with the risk for locally strong gusts again mainly limited to areas near the island mountain ranges across eastern portions of north-central MT. A somewhat greater coverage of flurries or snow showers is possible Tue/Wed, again favoring areas near the central MT mountains.

Multi-model ensemble means continue to broadly support the potential for a more significant surge of cold air and potential for snowfall by Fri/Sat as Canadian troughing broadens westward with the offshore ridge lifting north toward AK. There is still a fair amount of spread from run to run and among models/members with the extent and depth of the troughing into the NW US. Hoenisch

- Forecast Confidence & Scenarios:

A High Wind Warning remains in effect through this morning for the Bears Paw mountains and adjacent areas as well as portions of Fergus county. After peaking Saturday evening, gusty northwest winds will re-intesify early this morning with the arrival of higher surface pressure and a slight increase in wind speeds aloft. Gusts in excess of 50 mph are likely to be fairly localized again, favoring locations just east/southeast of the Bears Paw, Judith and Snowy ranges.

While confidence is increasing in the turn toward much colder conditions late this week into next weekend there is still a fair amount of uncertainty with the depth/extent of the cold airmass and still low confidence in timing/amount of precipitation. Probabilities for daytime temperatures in the single digits or colder and subzero overnight temperatures are as high as 60-80% across the north- central MT plains by Saturday with much lower (<20%) probabilities for SW MT. There is a reasonable (30-50%) chance for 2" or greater snowfall amounts Fri/Sat across much of the area. Hoenisch

AVIATION

18/12Z TAF Period

Moisture embedded within northerly flow aloft will produce widespread broken cloud-cover across much of the area today. Mainly low-VFR cigs and mountain obscurations with a period of MVFR cigs possible this morning at some n-central MT terminals. Gusty north to northwest surface winds will peak this morning at most terminals with winds gradually diminishing this afternoon and evening. Hoenisch

PRELIMINARY POINT TEMPS/POPS

GTF 35 17 41 28 / 10 0 0 0 CTB 32 13 40 24 / 0 0 0 0 HLN 36 17 38 24 / 0 0 0 0 BZN 35 13 36 19 / 0 0 0 0 WYS 30 -3 28 4 / 0 0 0 0 DLN 36 15 39 19 / 0 0 0 0 HVR 31 10 33 21 / 0 0 0 0 LWT 34 14 39 23 / 10 0 0 0

TFX WATCHES/WARNINGS/ADVISORIES

High Wind Warning until 11 AM MST this morning for Bears Paw Mountains and Southern Blaine-Fergus County below 4500ft.