textproduct: Great Falls

KEY MESSAGES

- Periods of light mainly mountain snowfall continue along the Continental Divide and Southwestern Montana Mountains through most of the week. - Gusty winds expected along the Rocky Mountain Front each afternoon, with strongest winds on Tuesday. - Above average temperatures continue through the week.

DISCUSSION

/Issued 354 AM MST Sun Jan 4 2026/

- Meteorological Overview:

Upper level ridging that was anchored over the Great Basin late last week has begun to shift eastward as an upper level trough begins to dig into the West Coast. While this wont bring many changes to our weather, it will begin to bring some mid level moisture to the area. For most of us, this will just mean some increased cloudiness, but for a few areas along the Montana/Idaho border some periods of light snow will bring some minor snow accumulations.

As this trough pushes ashore and approaches the Northern Plains late Monday and Tuesday a lee trough will develop just east of the Rocky Mountain Front, which will increase the pressure gradient between Western Montana and the plains. As the trough moves overhead on Tuesday along with some increased winds in the mid levels (around 700 mb), strong winds will develop along the wind prone areas of the Rocky Mountain Front and adjacent plains. Otherwise, slightly cooler but still slightly warmer than average air works into the area, which will linger through the remainder of the work week. This cooler air will be accompanied by zonal flow aloft, which will bring multiple weak weather systems through the area, resulting in more rounds of generally light snowfall over the mountains through the end of the week.

- Forecast Confidence & Scenarios:

The most impactful part of the forecast that I foresee over the next week will be the increased winds along the Rocky Mountain Front and adjacent plains on Tuesday. Current NBM probabilities suggest around an 80% or greater chance for 55 mph wind gusts in the usually wind prone areas along the Front, which are backed up by the strong pressure gradient and similar wind speeds at 700 mb. With this in mind, I have gone ahead and issued a High Wind Watch for these areas. Ludwig

AVIATION

04/12Z TAF Period

While VFR conditions are expected to be the norm across North Central and Southwestern Montana this morning, low clouds and thin fog will continue to persist in and around KHVR through 15z or so.

Otherwise the main concern this TAF period will be for increasing surface winds in most locations during the day Sunday. Localized instances of low-level wind shear will be around where surface winds are slow to develop late Sunday morning into the afternoon, including KBZN. -AM/ML

PRELIMINARY POINT TEMPS/POPS

GTF 53 31 47 29 / 0 0 0 10 CTB 47 26 41 26 / 10 0 0 0 HLN 48 28 42 24 / 10 20 20 30 BZN 47 27 42 23 / 0 10 20 30 WYS 36 25 33 21 / 60 60 70 60 DLN 46 27 42 24 / 10 10 10 10 HVR 45 25 42 22 / 0 0 0 0 LWT 51 30 46 24 / 0 0 10 20

TFX WATCHES/WARNINGS/ADVISORIES

High Wind Watch from Monday evening through Tuesday evening for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains- Southern Rocky Mountain Front.