Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
660 FXUS65 KMSO 100805 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 205 AM MDT Wed Jul 10 2024 ...This Afternoon Will Be The Hottest Day This Week... .DISCUSSION...Dangerously hot conditions, especially in north- central Idaho will continue today. While temperatures will remain hot and well above normal Thursday and through the weekend, the Excessive Heat Warnings and Heat Advisories have been trimmed back to expire this evening. Many western Montana valleys, such as Libby, Thompson Falls, Missoula, and Stevensville, just to name a few, have around a 70-80% probability of reaching the century mark this afternoon. Locations where Excessive Heat Warnings are currently in effect in north- central Idaho, will see temperatures ranging from 100-110F A subtle disturbance will pass through the region on Thursday causing the ridge to flatten. This feature will cause temperatures to cool slightly, around 5 degrees, but afternoon readings will still be extremely warm for this time of year. The disturbance will also cause increased westerly winds Thursday afternoon and evening. The combination of winds and low humidity readings will be approaching critical fire weather conditions, especially across southwest Montana. There is also an outside chance (10-15% chance), that isolated dry thunderstorms will develop Thursday afternoon and evening across southwest Montana. The ridge axis nudges to the east Friday into the weekend. This shift in the ridge will place the Northern Rockies in subtle southwesterly flow aloft. This flow appears to allow some monsoonal moisture to make its way up into the region by Saturday afternoon causing isolated high-based storms over southwest Montana and Lemhi County. && .AVIATION...VFR conditions are expected through Thursday. Well above normal temperatures will continue for all aviation sites this week. There is around a 70% Probability temperatures will reach or exceed 100F at KMSO this afternoon. The probabilities are much lower, around 20%, at KGPI. Smoke from regional wildfires in Oregon and Washington will further create hazy conditions across the region today especially 10/23z till 11/03z. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Heat Advisory until 11 PM MDT Wednesday for Flathead/Mission Valleys...Kootenai/Cabinet Region...Lower Clark Fork Region...Missoula/Bitterroot Valleys. ID...Heat Advisory until 10 PM PDT Wednesday for Northern Clearwater Mountains. Excessive Heat Warning until 10 PM PDT Wednesday for Lower Hells Canyon/Salmon River Region...Orofino/Grangeville Region... Southern Clearwater Mountains. && $$