BOZEMAN – Interesting weather pattern over the next 7 to 10 days for Montana. First, comes a short-lived heatwave Friday through Sunday. Second, look for a pattern change by Monday with cooler temperatures, showers, and thunderstorms with a Canadian storm dropping down into Montana.
High-pressure is lifting into the Pacific NW sending temperatures into the upper 90s to low 100s across Oregon and Washington. Some of this heat will drift into western Montana beginning Friday. By the weekend, most of Montana should see highs in the 90s to lower 100s.
Wildfire smoke is likely to worsen as well beginning Thursday afternoon. At times the smoke could be rather thick this weekend so look for deteriorating air quality conditions.
A Pacific storm will begin to migrate through Canada Saturday and begin to drop down into Montana Sunday night into Monday. Ahead of this storm a stronger SW flow will develop and trigger a heatwave and worse smoke described above. This storm will drop a cold front through Montana from north to south by Monday.
Cooler temperatures, gusty winds, and scattered showers or thunderstorms will develop with this frontal system early next week. The best news is cooler temperatures should stay over the region with a NW flow aloft through most of next week. Forecast highs will be below normal next week with a mix of 60s and 70s and only a few lower 80s across the state.
Finally, the updated drought monitor shows very little change in conditions over Montana from last week to this week. In fact, the percentages of Exceptional, Extreme, Severe, and Moderate drought remained the same thanks to the Pacific storm that passed through earlier this week. The widespread rain and thunderstorms from Sunday into Monday was not enough to reduce drought conditions over Montana and only brought a few days of relief.