Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
305 FXUS65 KMSO 062003 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 203 PM MDT Sat Jul 6 2024 .DISCUSSION...The Northern Rockies is under northwesterly flow this afternoon which will cause some gusty northwesterly winds and a few showers along the Continental Divide. A ridge of high pressure builds over the region Sunday through much of next week. This ridge will cause excessive heat over the Northern Rockies. The valleys of north central Idaho have an 80 to 100% probability of having temperatures of 100 degrees or higher on Wednesday. While Montana valleys west of Highway 93 generally have a 50 to 80% chance of breaking into the century mark on Wednesday afternoon. The combination of extremely hot days along with warm nights, especially in the valleys of north central Idaho, will create hazardous heat conditions so Excessive Heat warnings and advisories have been issued. A subtle disturbance moves through the region Wednesday into Thursday which will flatten the ridge slightly. This feature will have minimal impacts on the temperatures, but the increase in westerly winds is anticipated. A second disturbance is expected to move along the Canadian border next weekend. This feature will cool temperatures slightly along with the potential for a few showers and thunderstorms to develop across southwest Montana during the afternoon and evening. && .AVIATION...The Northern Rockies will be under northwesterly flow this afternoon and evening. This flow pattern will keep gusty northwesterly winds at area terminals. The majority of western Montana will experience scattered cumulus clouds until sunset with the potential of a few showers developing along the Divide this afternoon. The clouds and winds will begin to diminish around 07/02z. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Heat Advisory from 1 PM Tuesday to midnight MDT Friday night for Flathead/Mission Valleys...Kootenai/Cabinet Region...Lower Clark Fork Region...Missoula/Bitterroot Valleys. ID...Heat Advisory from noon Tuesday to 11 PM PDT Friday for Northern Clearwater Mountains. Excessive Heat Warning from noon Tuesday to 11 PM PDT Friday for Orofino/Grangeville Region...Southern Clearwater Mountains. Excessive Heat Warning from noon Monday to 11 PM PDT Friday for Lower Hells Canyon/Salmon River Region. && $$