textproduct: Great Falls

KEY MESSAGES

- Strong and gusty winds over eastern portions of Central and North Central Montana through Friday morning, mainly northeast of a Judith Gap to Sweet Grass Hills line.

- Afternoon temperatures not quite as warm as they have been, but still mostly above normal for most areas over the next week.

UPDATE

/Issued 854 PM MST Thu Jan 15 2026/

Biggest change this evening was that I trimmed the High Wind Warning from Judith Basin County as winds have generally been under performing across the area this evening. I strongly considered removing Toole and Liberty counties as well, but I think there is still a decent chance that a few spots in the Sweetgrass Hills hit. While impacts from a few isolated High Winds will be minimal, I decided to leave them in for the time being. Ludwig

DISCUSSION

/Issued 854 PM MST Thu Jan 15 2026/

A strong cold front, which was associated with an upper level shortwave digging to the southeast from over the Canadian Prairie Provinces, will continue to surge south through the remainder of Southwest Montana this afternoon and into Northern Idaho. While significant temperature drops in excess of 10+ degrees over a short amount of time (i.e. less than 30 minutes) have not been common with this front, with most locations seeing between a 5-10 degree drop over a 30-60 minute period of time, strong northerly wind gusts of between 45-55 mph were occurring across most locations along the initial frontal passage (T+2hr).

Satellite imagery showed expansive mid-level cloud cover over and north of the Island Ranges towards the International Border, with skies then clearing along and northeast of a Claresholm, AB, to Bow Island, AB, to Onefour, AB, to Chinook, MT line. As this clearing line, which is where sinking motion is occurring in wake of the upper level shortwave, advances to the southeast expect surface winds to increase from the north due to mixing. These winds will be especially strong and gusty northeast of a Judith Gap to Sweet Grass Hills line where a strong low to mid-level jet of 35-50kts will reside through Friday morning. Areas immediately to the southeast of the Island Ranges across the aforementioned areas of eastern Central and North Central Montana, along with those locations in terrain gaps, will be the most susceptible to seeing the strongest winds through Friday morning due to downsloping or terrain funneling. WInds will gradually subside through the day on Friday, with otherwise "lighter" winds expected through the next week outside of the Rocky Mountain Front.

Strong mid-level frontogenesis draped across Central and into portions of North Central Montana combined with northerly upslope flow will also support a period of snow showers over the Island Ranges and in their northern foothills through the early evening hours tonight. These snow showers could produce brief periods of moderate to heavy snow, especially across the Little Belt and Snowy Mountains. Visibilities beneath these heavier burst of snow could fall to as low as 1 mile at times, with snowfall accumulations of between 1-2 inches (generally between 5000-7000ft). - Moldan

AVIATION

16/06Z TAF Period

VFR conditions will prevail across all terminals during this TAF Period. It will windy at the KHVR and KLWT terminals during the majority of this TAF Period. From now through 16/15Z there will be isolated instances of low-level wind shear and mountain wave turbulence. During the first few hours of this TAF Period there will be mountain obscuration across Southwestern Montana. -IG

PRELIMINARY POINT TEMPS/POPS

GTF 22 34 16 48 / 10 0 0 0 CTB 18 33 13 49 / 0 0 0 0 HLN 21 35 14 42 / 20 0 0 0 BZN 16 31 9 40 / 10 0 0 0 WYS 0 26 -4 31 / 0 0 0 0 DLN 17 34 12 41 / 0 0 0 0 HVR 19 29 9 39 / 0 0 0 0 LWT 18 28 13 46 / 20 0 0 0

TFX WATCHES/WARNINGS/ADVISORIES

High Wind Warning until 5 AM MST Friday for Bears Paw Mountains and Southern Blaine-Eastern Toole and Liberty-Fergus County below 4500ft-Hill County-Northern Blaine County.