866 FXUS65 KTFX 122050 AFDTFXArea Forecast Discussion National Weather Service Great Falls MT 250 PM MDT Fri Sep 12 2025
.KEY MESSAGES...
- Scattered showers and thunderstorms will continue across north-central and central Montana through the evening.
- Above normal temperatures and daily chances for showers and thunderstorms will continue through the weekend.
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.DISCUSSION...
- Meteorological Overview:
Thunderstorms are already underway across portions of central and north-central Montana with the strongest storms expected in Judith Basin, Fergus, and Blaine counties. The latest CAMs show MLCAPE in the 1500-2000 J/kg range which is more than sufficient to kick of stronger storms. Due to a lack of shear, these storms are quasi- stationary at the moment which may become a concern for localized flash flooding under stronger cells.
An active pattern will continue through the weekend with daily chances for showers and thunderstorms across the region. Above normal temperatures will persist across north-central and central Montana with more seasonably temperatures expected across southwest Montana.
- Forecast Confidence & Scenarios:
Right now the main concern are the storms firing off of the Little Belt and Bears Paw mountains. Some gusty winds, generally less than 40 mph, are expected along with small hail. There is a concern that a couple of these thunderstorms may get stronger and produce locally stronger wind gusts up to 50 mph and larger hail up to 1 inch. At this time, widespread severe weather is not expected with the biggest threat for severe thunderstorms off to the east of our area.
Otherwise the primary concern is how slow these storms are moving. Quite a few of the storms that have developed have storm motions of 5 to 10 mph which is expected given the lack of shear but it also means that the threat for flooding starts to slowly tick up the longer these storms stall over one area. For now, there is low confidence (
NWS TFX Office Area Forecast Discussion