It’s the second-to-last full weekend of summer with heat and wildfire smoke spreading widely across Montana. Air quality was “unhealthy” in the Bitterroot on Friday, and that smoke will continue to spread east through the weekend. Saturday will be warm and sunny with highs in the 80s and 90s under a sunny but foggy sky. Smoke will slowly increase from west to east. There will be a light easterly wind. Sunday, upper-level flow will turn southwest, pushing wildfire smoke across Big Sky. A few isolated thunderstorms will build across the western mountains, including around Helena. Highs will be warm in the 90s. Monday will be a windy, hot, dry day with highs in the 80s and 90s. Smoke could be thick and air quality could be poor. Changes will begin on Tuesday with a cold front pushing south from Canada. A few isolated thunderstorms are possible and highs will cool to just the 80s. A storm system will move in from the Pacific on Wednesday with scattered showers and thunderstorms and cooler highs in the 70s. Scattered showers are possible on Thursday with cooler temperatures in the 60s and a chance of snow at higher elevations. This storm should bring rain and cooler temperatures to Oregon, Idaho and southwestern Montana, where smoke is prevalent.

Enjoy the weekend,
Curtis Grevenitz
Chief Meteorologist