722 FXUS65 KGGW 222022 AFDGGWArea Forecast Discussion National Weather Service Glasgow MT 222 PM MDT Mon Sep 22 2025
.DISCUSSION... KEY MESSAGES:
- Gusty northwest winds and slight chances for rain continue through this afternoon behind the cold front passage.
- A Lake Wind Advisory is in effect through 6pm today.
- The remainder of the week will be warm and dry.
WEATHER PATTERN OVERVIEW: A narrow upper trough is working its way though east through central Montana. This trough is expected to push south then east, forming a partially closed low. This will form the eastern low on a quasi omega block with another low off the southern California coast. The upper ridge of the system will extend north into Montana by midweek with fast zonal flow over Canada.
Cooler temperatures will also drop south behind the front, before warming into midweek with the building ridge. Temperatures level off after midweek with the Canadian zonal flow becoming more dominant for northeast Montana.
FORECAST CONFIDENCE & DEVIATIONS: The upper low centered off the coast of California has decent model agreement through Friday, the timing in which it moves off or dissipates is less certain. While this low remains it will drive mostly zonal flow with the possibility for shortwave troughing/ridging that may cause small disturbances in northeast Montana.
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.AVIATION... UPDATE: 1930Z, September 22
FLIGHT CAT RANGE: VFR
DISCUSSION: Clear skies will return to the region by tomorrow morning. Broken midlevel clouds will continue to push eastward while chances of rain remain in southern and central Montana.
WIND: Gusty northwest winds will continue through the evening. By 6Z winds will calm to 4 to 5 kts and become variable. After 14Z tomorrow a partially closed low moving through southern Montana will cause a wind shift from generally west winds ahead of the low to south winds behind the low. EQUIPMENT: KSDY AMD NOT SKED will remain in place until METARs comms issue is repaired.
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.GGW WATCHES/WARNINGS/ADVISORIES... Lake Wind Advisory until 6 PM MDT this evening for Central and Southeast Phillips-Central and Southern Valley-Garfield-McCone- Petroleum.
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weather.gov/glasgow
NWS GGW Office Area Forecast Discussion