Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
929 FXUS65 KGGW 241859 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 1259 PM MDT Fri Jul 24 2026 .KEY MESSAGES... - Temperatures in the 90s to low 100s for highs are expected this weekend into most of next week. An Extreme Heat Warning is in effect through Sunday...for now. - Dry conditions most of the time but there could be an isolated thunderstorm in the evening tonight and tomorrow evening. - Mainly dry and breezy conditions today. A Red Flag Warning is in effect today and tomorrow afternoon and evening for various locations. && .DISCUSSION... WEATHER PATTERN OVERVIEW: An upper ridge over the western states is bringing the heat back to the area. The base NBM has 100 degrees forecast for at least a few locations through Wednesday. Today, a shortwave trough is expected to bring an isolated storm to the southwest and northeast. The main concern is gusty outflow winds. A shortwave trough is expected to move into the southwest part of the area tomorrow afternoon and evening, and the main concern is gusty winds again. The base HREF has gusts up to around 60 mph, and the maximum HREF has gusts up to 80 mph. There is a low probability of 80 mph occurring tomorrow. The main concern for fire starts is low humidity and strong winds for today, and lightning strikes tomorrow. There is a Red Flag Warning out for fire zones 122, 135, 134, 137, and 136 for today, and fire zones 134, 135, 136, and 137 for tomorrow afternoon and evening. Abundant smoke from the Pacific NW fires is over the area, and mainly reducing visibility from 1 KM to 6 KM above the ground. There is a chance of this haze and smoke affecting sensitive groups near the ground for smoke that does reach the ground. West winds are strong enough to support the Lake Wind Advisory from now through 6 PM this evening. There is an Extreme Heat Warning in effect for this strong ridge that has aided in bringing temperatures up. These warm conditions during the day and poor temperature recoveries at night (temperatures staying above 65 degrees) will make it important to have efficient cooling systems in place. These poor temperature recoveries are in the forecast in the southern half of the area through Thursday. FORECAST CONFIDENCE & DEVIATIONS: The only deviation was to add a slight chance of PoPs to various parts of the area through tomorrow evening. There is high confidence in the heat products that are in effect through Sunday evening. There is moderate confidence in heat products being needed again during the week. There is low to moderate confidence in severe wind gusts occurring in the northeast this evening and in the west tomorrow afternoon and evening. There is high confidence in smoke moving through the area from 1 kilometer and 6 kilometer above the ground through tomorrow morning, and moderate confidence in surface haze and smoke occurring. There is high confidence in the Red Flag Warning verifying today, and moderate confidence for tomorrow. This confidence is the same for the Lake Wind Advisory in effect for today. && .AVIATION... UPDATE TIME: 1830Z FLIGHT CATEGORY: Mostly VFR. MVFR in isolated thunderstorms, haze, ans smoke. SYNOPSIS: An upper ridge is over the area. The main concern at TAF sites through 20Z tomorrow is haze and smoke. There is some indication this will be near the ground today, but most of it is lofted from 2 KM to 6 KM off the surface through about 03Z. Then another round is expected to affect the area from about 03Z through about 12Z Saturday. There is moderate confidence to high confidence of visibilities reaching down to 6 miles, and low confidence in visibility lower than that. The next concern is isolated thunderstorms tomorrow evening from 22Z Saturday to 04Z Saturday for KGGW. DENSITY ALTITUDE: Issues are expected at times with the heat today through Sunday at the terminals as temperatures hang around the 100 degree mark. WINDS: Northwest at 10 to 20 knots with gusts to 28 knots, decreasing to light and variable after 03Z. && .FIRE WEATHER... Upper level ridge moves east across the region today and may topple over after Sunday. Highs will be in the 80s initially with a chance for showers mid-day today. Outside of these isolated showers no wetting rains are expected through the work week. Then, expect a slow warm up back to near 100s Friday through the weekend. && .GGW WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 9 PM MDT this evening for Dawson/McCone/Prairie/Richland/Wibaux 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. Red Flag Warning from 4 PM to 10 PM MDT Saturday for 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. Lake Wind Advisory until 6 PM MDT this evening for Central and Southeast Phillips-Central and Southern Valley-Garfield-McCone- Petroleum. Extreme Heat Warning until 10 PM MDT Sunday for Central and Southeast Phillips-Central and Southern Valley-Daniels-Dawson- Eastern Roosevelt-Garfield-McCone-Northern Phillips-Northern Valley-Petroleum-Prairie-Richland-Sheridan-Southwest Phillips- Western Roosevelt-Wibaux. && $$ weather.gov/glasgow