A breakdown in the upper level ridge brought stronger mid level winds and a strong surface pressure gradient to the Rocky Mountain Front. A cold front passing through helped mix these stronger winds down to the surface and produce an isolated high wind gust.
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The episode as NWS TFX wrote it up.
A breakdown in the upper level ridge brought stronger mid level winds and a strong surface pressure gradient to the Rocky Mountain Front. A cold front passing through helped mix these stronger winds down to the surface and produce an isolated high wind gust.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Great Falls, MT wrote its last area forecast discussion before the first event at Sep 21, 4:26 PM MST, 14 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Great Falls MT 526 PM MDT Sun Sep 21 2025 Aviation Section Updated. .KEY MESSAGES... - Scattered showers and thunderstorms through tonight. - A cooler, but seasonable day expected on Monday. - It turns dry and warm from Tuesday into next weekend. && .DISCUSSION... /Issued 243 PM MDT Sun Sep 21 2025/ - Meteorological Overview: A Pacific cold front is approaching the Rocky Mountain Front currently. Scattered showers and thunderstorms are developing ahead and along the cold front. The cold front will move eastward across the CWA this evening and overnight tonight. There will be a few stronger storms, with the main impact being gusty winds. By Monday morning, snow levels will fall down to about 8000 or 9000 feet, with a rain/snow mix possible at ridge tops. For Monday, afternoon temperatures will be cooler than they have been, but still close to seasonal normals. The cool air will not last long, as warmer air moves back into the CWA on Tuesday. By Wednesday, afternoon highs will be in the mid 80s to near 90 degrees, which will be about 15 to 20 degrees above normal for this time of year. The above normal temperatures, will continue into next weekend, just not as hot as the mid week temperatures though. This system will be rather quick moving, and there will only be a few lingering showers on Monday morning, especially over the central mountains, otherwise dry conditions are expected until late next weekend. - Forecast Confidence & Scenarios: An isolated strong wind gust is possible with the thunderstorms tonight, but the threat/possibility for any severe storms is quite low. Most areas will see rainfall less than 0.20 inches, but an isolated stronger storm could produce near a half inch of rainfall. After this system exits the region on Monday morning, the chance for rainfall is almost near zero until late next weekend. Even the system for late next weekend only has very low chances for precip at this time. Afternoon temperatures for Wednesday continue to increase as well. Thus some areas will once again approach 90 degrees for afternoon high temperatures. && .AVIATION... 22/00Z TAF Period. A Pacific cold front will continue east across north-central and southwest MT this evening with main impact to aviation being gusty and shifting winds, both with showers and thunderstorms ahead of the front and with the passage of the front itself. Showers and thunderstorms early this evening will bring some brief MVFR and mountain obscuration with a more widespread area of showers and lower cloud ceilings developing across primarily southwest MT overnight, through some showers and periods periods of MVFR ceilings are also possible for a shorter period overnight across north-central MT. Gusty west to northwest winds continue through tonight after the frontal passage before slowly diminishing Monday morning with clouds clearing by Monday afternoon. Hoenisch && .PRELIMINARY POINT TEMPS/POPS... GTF 48 67 42 77 / 70 10 0 0 CTB 45 67 37 78 / 30 20 0 0 HLN 46 66 40 76 / 70 10 0 0 BZN 44 62 35 71 / 90 30 0 0 WYS 36 56 24 67 / 90 60 0 0 DLN 41 61 33 70 / 90 10 0 0 HVR 49 67 40 78 / 60 20 0 0 LWT 46 59 39 74 / 80 30 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && http://www.weather.gov/greatfalls
Preliminary Local Storm Report
National Weather Service Great Falls MT
455 PM MDT Sun Sep 21 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0440 PM Non-Tstm Wnd Gst 3 SW Cut Bank 48.60N 112.37W
09/21/2025 M59 MPH Glacier MT ASOS
ASOS station KCTB Cut Bank Airport.
&&
BrusdaThe national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
ASOS station KCTB Cut Bank Airport measured a 59 mph wind gust.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2025Every state in 2025This day in weather historyWarnings in Montana, September 2025
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1288139.