A major shift in atmospheric conditions is expected to bring cooler conditions across the West–which will thankfully help firefighters battling late-summer blazes–and bring snow to higher elevations in the Northern Rockies by the weekend. The West will also experience much cooler temperatures, ushering in fall as ski and snowboard films will premiere in places like Jackson Hole.
According to the Weather Channel, the changes come thanks to a jet stream shift where the stream in the west will dip southward which allows colder conditions to come in. Meanwhile, that jet stream will push further north as it moves east, bringing cooler temps to the Midwest and Northeast.
Rains will spread over northern Arizona, New Mexico, Idaho and Montana and with chilly temperatures expected (20s and 30s in Idaho and Montana), snow accumulation could be as much as a whopping 1-2 feet above 6,000 feet. Winter weather advisories will be in effect. Backcountry and early season resort-hiking may come earlier than we think. Or are even ready for.