Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
705 FXUS65 KGGW 310602 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 1202 AM MDT Fri Jul 31 2026 .KEY MESSAGES... - Saturday will be one of the hottest days of the summer with temperatures reaching or exceeding 100 in many places. A Excessive Heat Watch covers Saturday and Saturday night as overnight temperatures are not expected to drop below the low to mid 70s in most places. - Northwest winds ramp up significantly Sunday in the wake of a frontal system. Critical fire weather conditions can be expected with very low humidities (10-20%) and winds 15-25 mph with possible gusts to 40 mph. - There will be an overall cooldown across the region next week, with a near 20-30 degree high temperature dropoff between Saturday to Monday. && .DISCUSSION... WEATHER PATTERN OVERVIEW: Upper air pattern showing an upper ridge over most of the country with a very strong upper low over the Gulf of Alaska. Said upper ridge will help to heat things through Saturday across northeast Montana as nearly full sun and rising 500 mb heights will allow temps to be warmer or much warmer than what they were Thursday with highs today in the 90s most places. Look for highs Saturday to be 90s in the northeast with 100-110 elsewhere. A Excessive Heat Watch remains in effect for Saturday and Saturday night. The strong upper low over the Gulf of Alaska will move east translating to an upper trough over west-central Canada by Tuesday. This will send a couple of cool fronts across the area, the first one arriving early Sunday morning with the second pushing through Monday morning. Wind will signal their arrival as only small chances of brief showers are expected Sunday night. The wind with the leftover warm air late Saturday and Sunday could result in Fire Weather issues. A Fire Weather Watch remains in effect for this period. Windy conditions Saturday night through Monday will also likely need a Lake Wind Advisory. After Monday, the upper trough moves east and a zonal flow succumbs a bit to a Desert southwest ridge by the end of the forecast cycle. Expect dry conditions with temperatures warming to near normal. Winds generally look light so Fire Weather issues should be minimal. FORECAST CONFIDENCE & DEVIATIONS: High confidence in the hot weather Friday and Saturday. Confidence is moderate to high for critical fire weather conditions Sunday. Low confidence in amounts and timing of showers Sunday night. No major changes were made from the base forecast with this forecast package. TFJ && .AVIATION... FLIGHT CATEGORY: VFR. DISCUSSION: Mainly clear or sunny conditions are expected into tonight except for small chance for a thunderstorm northeast of KOLF/KSDY Friday evening. WINDS: Southeast winds at 10-20 kts will turn more south during the afternoon. DENSITY ALTITUDE: Will be a concern especially Saturday with temperatures near or over 100. Extra power and longer runway will be needed for takeoffs. TFJ && .GGW WATCHES/WARNINGS/ADVISORIES... Extreme Heat Watch from Saturday afternoon through Sunday morning for Central and Southeast Phillips-Central and Southern Valley-Garfield-Northern Phillips-Northern Valley-Petroleum- Southwest Phillips. Fire Weather Watch from Saturday afternoon through Sunday evening for Dawson/McCone/Prairie/Richland/Wibaux Counties-Fort Peck Reservation and Daniels/Roosevelt/Sheridan Counties- Northern Valley and Northern Phillips Counties-Southern Petroleum and Southern Garfield Counties-The Little Rockies-The Lower Missouri River Breaks including the Charles M Russell National Wildlife Refuge. Extreme Heat Watch from Saturday afternoon through Sunday afternoon for Daniels-Dawson-Eastern Roosevelt-McCone-Prairie- Richland-Sheridan-Western Roosevelt-Wibaux. && $$ weather.gov/glasgow