


Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
598 FXUS65 KMSO 071933 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 133 PM MDT Mon Jul 7 2025 .DISCUSSION... KEY MESSAGES: - Hot mostly dry on Tuesday - Increasing thunderstorm chances on Tuesday and Wednesday, capable of gusty winds - Cooler, showery, and breezy by Thursday High pressure is expected to peak on Tuesday, bringing hot temperatures across the region. Daytime highs in the lower valleys of north-central Idaho are forecast to reach 100-108F, with warm overnight lows in the mid-60s to low 70s. This combination will result in moderate to major heat impacts, and a heat advisory is in effect. Moisture will also increase from the southwest, bringing afternoon and evening thunderstorm chances. The main focus for storms capable of producing gusty outflow winds is the southern half of Idaho County, Lemhi County, and southwest Montana. Moisture will continue to increase Tuesday night, with high- resolution models showing isolated showers and thunderstorms overnight. More widespread thunderstorms are expected late Wednesday afternoon through the evening. Breezy winds will also develop across north-central Idaho and western Montana Wednesday afternoon, which, combined with hot and dry conditions, will increase fire weather concerns, especially in north-central Idaho. Model guidance has been trending toward a deeper trough dropping out of Canada on Thursday. This system and its cold front will bring cooler daytime temperatures, northwest winds, and higher chances for showers. The best chance for rain appears to be in northwest Montana, with cool and wet conditions likely in the Glacier region. A warming and drying trend is expected to return Friday and continue through the weekend as high pressure builds back into the Northern Rockies. && .AVIATION...High pressure will peak Tuesday, bringing hot temperatures and density altitude concerns, especially in north- central Idaho where valley highs will reach 100-108F with warm overnight lows. A heat advisory is in effect. Moisture will increase from the southwest, with scattered afternoon and evening thunderstorms possible Tuesday, mainly over the southern half of Idaho County, Lemhi County, and into southwest Montana. Gusty outflow winds will be the main hazard. Isolated showers or storms may linger overnight Tuesday. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...Red Flag Warning from 11 AM to 8 PM PDT Wednesday for Palouse/Hells Canyon. Heat Advisory from 11 AM to 9 PM PDT Tuesday for Lower Hells Canyon/Salmon River Region...Orofino/Grangeville Region. && $$