613 FXUS65 KTFX 261138 AFDTFXArea Forecast Discussion National Weather Service Great Falls MT 538 AM MDT Fri Sep 26 2025
Aviation Section Updated.
.KEY MESSAGES...
- A quick moving cool front will move from west to east across the CWA this morning, brining in a bit cooler temperatures for this afternoon.
- Dry and quiet weather conditions continue through Sunday morning, before the chances for showers and thunderstorms increase over Southwest MT on Sunday afternoon.
- Expect above normal temperatures early next week, with cooler temperatures by late next week.
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.DISCUSSION... - Meteorological Overview: Quiet weather conditions overnight will give way to a fast moving cool front that will move from west to east across the CWA this morning. The main effect from this front will be for one day of cooler temperatures this afternoon, and a short period of increased smoke as the front moves through. Otherwise, dry conditions are expected across the CWA through Sunday morning.
The flow aloft will shift to a more southwesterly flow on Sunday, as a strong area of low pressure develops off the coast of Washington state. This will allow for scattered showers/thunderstorms to develop over Southwest MT on Sunday afternoon, and then gradually spread northward Sunday night into Wednesday. Overall, no severe storms are expected, but a few storms could produce some gusty winds or brief heavy rainfall. This will be a slow moving upper level trof that moves from west to east across the CWA early next week, with temperatures not cooling off until about Wednesday.
- Forecast Confidence & Scenarios: The main weather concern will start on Sunday afternoon with showers/thunderstorms over Southwest MT. This chance for showers/thunderstorms will increase daily through Wednesday. Overall, most areas will have light precipitation, there is about a 20 percent chance that some areas could receive brief heavy rainfall.
In terms of temperatures, above normal temperatures are expected most day through Tuesday, before temperatures return back closer to seasonal normals for late next week. Brusda
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.AVIATION... 26/12Z TAF Period.
VFR conditions will prevail across the CWA through the period. However, do a Pacific front will move from west to east across the CWA this morning, with a slight wind shift at the surface to the northwest over North Central MT. Some smoke will also drift across the CWA this morning with the frontal boundary, reducing distant visibility at times. Expect a band of mid/high level clouds this morning, along with breezy winds this afternoon. Skies clear out and winds diminish early this evening. Mountains/passes could be obscured at times through this afternoon by smoke. Brusda
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.PRELIMINARY POINT TEMPS/POPS... GTF 72 45 81 46 / 0 0 0 0 CTB 68 43 76 43 / 0 0 0 0 HLN 72 41 79 46 / 0 0 0 0 BZN 73 37 79 42 / 0 0 0 0 WYS 69 29 70 31 / 0 0 0 0 DLN 71 36 77 40 / 0 0 0 0 HVR 70 42 80 46 / 0 0 0 0 LWT 69 42 79 48 / 0 0 0 0
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.TFX WATCHES/WARNINGS/ADVISORIES... None.
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$$ http://www.weather.gov/greatfalls
NWS TFX Office Area Forecast Discussion