Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
899 FXUS65 KGGW 092116 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 316 PM MDT Wed Jul 9 2025 .DISCUSSION... KEY MESSAGES: 1) Hot July conditions will continue with high temperatures in the 100s today (Wednesday). A Heat Advisory is in effect today, highlighting the risk for heat related illnesses. 2) A Red Flag Warning is in effect for this afternoon and evening. 3) Strong frontal system winds will generate winds of 20 to 30 mph Thursday afternoon. A Lake Wind Advisory is in effect. WEATHER PATTERN OVERVIEW: The ridge of high pressure will shift a bit more over the northern High Plains this afternoon and then collapse eastward tonight. Many locations have reached near or above 100 degrees. Thankfully, with such a dry atmosphere, the heat index will actually be lower than the actual temperature. But hot is still hot, and the Heat Risk guidance suggests that major heat illness impacts are possible across most northeast Montana locations for those not taking necessary precautions. Today, some isolated to scattered high based thunderstorms have already developed over southern Montana and are moving toward the northeast. Some model data suggests that these storms could form strong downdraft wind gusts which would move into northeast Montana later this afternoon and evening. Models also continue to show very little, if any, rain resulting from them, which raises concerns for dry lightning. See fire weather discussion below. Relief, in the form of cooler air is expected Thursday and Friday. But the gradual frontal passage could also lead to some widespread gusty winds. Heat will return under another dome of high pressure on Saturday and Sunday. FORECAST CONFIDENCE & DEVIATIONS: There is high confidence of temperatures reaching near or above 100 for many locations today. Dry thunderstorms with gusty to near severe wind gusts late this afternoon and early evening is average confidence. Deviations included high-res model wind data to capture expected downdraft wind gusts. && .AVIATION... LAST UPDATED: 2115Z FLIGHT CAT RANGE: VFR. DISCUSSION: Isolated to scattered thunderstorms may sneak into the region later this afternoon and evening, but the hot high pressure may suppress some of that development. WINDS: Winds from the W or NW today around 15 mph with a few stronger gusts. Gusty erratic winds could happen near any thunderstorms this afternoon and evening. Winds will then become light and variable overnight tonight. && .FIRE WEATHER... Isolated to scattered showers/thunderstorms are expected this afternoon and evening, ahead of a frontal passage later tonight. Lightning over dry fuels could lead to some new starts and downdraft gusts from collapsing cells could be borderline severe, fanning new flames. Even with the green-up having occurred, fuels are quickly drying and are even lacking in overall green-ness for much of the area. && .GGW WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 9 PM MDT this evening 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. Red Flag Warning until 4 AM MDT Thursday 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. Lake Wind Advisory from 10 AM to 9 PM MDT Thursday for Central and Southeast Phillips-Central and Southern Valley-Garfield- McCone-Petroleum. && $$ weather.gov/glasgow