textproduct: Great Falls

KEY MESSAGES

- It will be mostly dry across North-central, Central, and Southwestern Montana through the day on Thursday.

- It will be windy across North-central Montana on Friday.

- Widespread precipitation returns late Thursday through Friday.

- Temperatures will be well-above seasonal averages through Thursday with temperatures cooling down Friday through this weekend.

DISCUSSION

/Issued 140 AM MDT Wed Oct 21 2026/

- Meteorological Overview:

Today over Southwestern Montana there remains Southwest flow aloft with weak zonal flow (west-east) over North-central, and Central Montana. Due to slightly stronger warm air advection today temperatures will rebound to above seasonal averages. Across North- central and Central Montana it will be dry with a low chance for showers across Southwestern Montana today. See the Forecast Confidence & Scenarios Section for details. On Thursday there remains southerly flow aloft and an upper-level trough associated with a Pacific Cold front begins to move over North-central, Central, and Southwestern Montana by Thursday evening. This will allow temperatures to remain above seasonal averages with mostly dry weather until Thursday evening. Thursday evening into Friday morning precipitation will gradually spread over North-central, Central, and Southwestern Montana.

On Friday the upper-level trough merges with a shortwave trough moving south from Canada. This combined with the cold front that moved through will bring widespread precipitation and cooler temperatures (below seasonal averages) to the area. Due to the cold front that moved through Thursday evening into Friday morning snow-levels will lower and the precipitation that falls in mountain areas on Friday will transition from rain to snow by Friday evening. On Friday there is an increasing pressure gradient and strong low-level and mid-level winds. This will bring windy conditions to North-central Montana on Friday. On Saturday an upper-level ridge begins to build in over North-central, Central, and Southwestern Montana. This will allow the area to dry out with cool temperatures lingering.

On Sunday the upper-level ridge remains over North-central, Central, and Southwestern Montana. This will keep dry and cool (below seasonal averages) weather for the area on Sunday. Monday through Tuesday an upper-level trough moves over North-central, Central, and Southwestern Montana. This will bring cooler temperatures and widespread precipitation to the area on Monday and Tuesday. -IG

- Forecast Confidence & Scenarios:

Today across Southwestern Montana along the Idaho/Montana Border there is a 10% chance for a tenth of rain or greater. On Friday there is a 40 - 65% chance for wind gusts of 45 mph or greater across much of North-central Montana. On Friday along the Rocky Mountain Front and plains west of I-15 there is a 30 - 50% chance for wind gusts of 55 mph or greater.

For total liquid precipitation Thursday night through Friday night there is greater than an 80% chance for one half inch of liquid precipitation or greater along and south of the Montana Highway 200/US Highway 87 Corridor between Great Falls and Lewistown. For total liquid precipitation Thursday night through Friday night there is a 30 - 60% chance for one half inch of liquid precipitation across North-central Montana north of the Montana Highway 200/US Highway 87 Corridor between Great Falls and Lewistown. For total liquid precipitation Thursday night through Friday night there is a 60 - 90% chance for one inch of liquid precipitation or greater across Central and Southwestern Montana. Across most of the mountains of North-central, Central, and Southwestern Montana there is greater than a 60% chance for 2 inches of snow or greater from Thursday night through Friday night. Thursday night through Friday night there is a 50 - 80% chance for 4 inches of snow or greater across the Madison and Gallatin ranges and the Little Belts. Friday afternoon into early Saturday morning there is a high chance that at least some lower-elevation locations across North-central, Central, and Southwestern Montana will see a few flakes of snow. -IG

AVIATION

21/12Z TAF Period

VFR conditions will prevail at all terminals during this TAF Period with primarily light winds and high-level clouds around. At the KWYS terminal between 21/15Z and 21/22Z there is a 15 - 30% chance for rain showers. -IG

PRELIMINARY POINT TEMPS/POPS

GTF 73 45 74 42 / 0 0 0 30 CTB 68 39 70 38 / 0 0 0 60 HLN 69 39 71 43 / 10 10 0 40 BZN 67 38 70 40 / 10 0 0 30 WYS 60 29 62 32 / 30 10 10 70 DLN 65 38 66 41 / 20 10 0 80 HVR 69 37 73 40 / 0 0 0 20 LWT 71 45 75 43 / 0 0 0 20

TFX WATCHES/WARNINGS/ADVISORIES

None.