textproduct: Great Falls

KEY MESSAGES

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

- There is a low chance for showers in Southwestern Montana on Tuesday and Wednesday.

- Widespread precipitation returns late Thursday through Friday.

- Outside of Tuesday temperatures will be well-above seasonal averages through Thursday.

DISCUSSION

/Issued 136 AM MDT Mon Oct 19 2026/

- Meteorological Overview:

Today there is an upper-level ridge over North-central, Central, and Southwestern Montana with strong southwesterly flow aloft. This will bring warm (well-above seasonal average) temperatures to the area with mostly dry weather. On Tuesday the upper-level ridge transitions to weak zonal flow (west-east) aloft over North-central and Central Montana with southerly flow aloft over Southwestern Montana. This will cool down temperatures to near seasonal averages. Due to some moisture moving over Southwestern Montana combined with weak southerly flow aloft there is a low chance for showers across Southwestern Montana on Tuesday. See the Forecast Confidence & Scenarios section for details. It will be dry across North-central and Central Montana on Tuesday.

On Wednesday 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 on Wednesday temperatures will rebound to above seasonal averages on Wednesday. Across North-central and Central Montana it will be dry with a low chance for showers across Southwestern Montana on Wednesday. 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 will bring widespread precipitation and cooler temperatures 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 be snow. On Friday there is an increasing pressure gradient and strong low-level and mid-level winds. This will bring windy condtions 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. -IG

- Forecast Confidence & Scenarios:

Tuesday through Wednesday 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 the Rocky Mountain Front, Hi-Line, Judith Basin and Fergus Counties.

For total liquid precipitation Thursday night through Saturday morning there is a 50 - 80% chance for one half inch of liquid precipitation or greater across most of Central and Southwestern Montana. For total liquid precipitation Thursday night through Saturday morning there is a 25 - 50% chance for a quarter inch of liquid precipitation across North-central Montana. For total liquid precipitation Thursday night through Saturday morning there is a 50 - 80% chance for one inch of liquid precipitation or greater across the Madison and Gallatin ranges and the Little Belts. 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 Saturday morning. Thursday night through Saturday morning there is a 50 - 70% chance for 4 inches of snow or greater across the Madison and Gallatin ranges. -IG

AVIATION

19/12Z TAF Period

VFR conditions will prevail at all terminals during this TAF Period. At all terminals but the KEKS terminal there will be light winds during this TAF Period. -IG

PRELIMINARY POINT TEMPS/POPS

GTF 71 39 56 36 / 0 0 0 0 CTB 61 35 54 31 / 0 0 0 0 HLN 68 35 61 35 / 0 0 0 0 BZN 67 34 63 33 / 0 0 10 10 WYS 59 25 58 27 / 0 10 20 10 DLN 65 34 62 36 / 0 0 10 10 HVR 66 33 60 30 / 0 0 0 0 LWT 71 40 56 34 / 0 0 0 0

TFX WATCHES/WARNINGS/ADVISORIES

None.