Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
259 FXUS65 KGGW 290711 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 111 AM MDT Sat Aug 29 2026 .KEY MESSAGES... - There will be chances for showers and thunderstorms today and tonight. - A cold front on Sunday will bring showers and thunderstorms at times. - Upper low will bring cooler temperatures and gusty west winds Sunday and Monday. && .DISCUSSION... WEATHER PATTERN OVERVIEW: SW flow aloft will be over Montana today as the upper ridge moves east and upper trough/low moves inland from the Pacific. The SW flow aloft will bring increasing moisture and instability into NE Montana today with chances for showers and thunderstorms developing across the region. The chances for showers and thunderstorms will continue at times tonight. The upper low moves into Montana Sunday morning> A cold front will move through eastern Montana during the day on Sunday with showers and thunderstorms at times. West winds behind the cold front Sunday afternoon may be strong enough for a Lake Wind Advisory over Fort Peck Lake. SPC has a Marginal Risk over most of the forecast area for severe weather on Sunday with damaging winds being the main threat. The upper low moves into Alberta and Saskatchewan Sunday night with most of Montana moving into a dry slot. The upper low will be over Saskatchewan on Monday with the dry slot and gusty west winds over the forecast area. A Lake Wind Advisory is likely for Fort Peck Lake on Monday. High pressure moves into the area Monday night with diminishing winds and upper ridge will bring dry weather with warmer temperatures on Tuesday. SW flow aloft is expected Wednesday and beyond with an upper trough/low over the Pacific NW and and upper ridge to the east. FORECAST CONFIDENCE & DEVIATIONS: Only deviation to NBM was to tweak PoPs today through Sunday. There is high confidence that there will be showers and thunderstorms at times this afternoon, tonight and Sunday with low confidence in timing and precipitation amounts. && .AVIATION... LAST UPDATED: 0700Z. FLIGHT CAT RANGE: VFR, MVFR in thunderstorms. DISCUSSION: Varying amounts of mid and high clouds are expected today and tonight. There will be chances for showers and thunderstorms after 18z today and continuing at times this afternoon and tonight. WINDS: Variable winds today less than 10 knots becoming northeast at 5 to 10 knots this evening and continue overnight. && .GGW WATCHES/WARNINGS/ADVISORIES... None. && $$ weather.gov/glasgow