MISSOULA — A few isolated thunderstorms can't be ruled out Friday for western Montana. The main threat here is lightning leading to new fire starts. These storms will be very isolated in nature, most will see sunny and very hot weather Friday.
A heatwave will continue to impact the Northern Rockies through this weekend as the western US remains under the influence of high pressure. Temperatures in the low elevations of central Idaho will top out around 105-112 degrees. Valley areas across western Montana will top out around 96-104 degrees. Heat advisories have been expanded to include the Flathead, Mission, Missoula, and Bitterroot Valleys through Sunday evening.
Looking ahead to next week, Monday will remain hot with highs once again pushing 100 degrees. Cooler air will then begin to move in by Tuesday as the ridge of high pressure breaks down. This will allow temperatures to drop closer to seasonal normal with highs back in the 80s. Northwest Montana could even be looking at temperatures in the upper 70s by the middle and end of next week.