A rare late-June snow event is covering parts of the northern Rockies with up to 12 inches of snow [1].
This weather anomaly highlights the extreme volatility of current atmospheric patterns, where winter-like conditions in the mountains coexist with a national heat wave.
The snowfall is impacting residents across Idaho, Montana, and Wyoming [2]. Specific areas under alert include the West Yellowstone gateway, Lemhi Pass, and Lost Trail Pass [3]. According to reports, the snow event began Saturday night and is expected to last through Monday morning [3].
Weather forecasts for the region have varied. Some reports indicate that the northern Rockies could see 12 inches of snow [1]. Other forecasts from the weather service suggest a maximum of eight inches [2].
Meteorologists said the phenomenon was caused by a late-season cold front and an unusually cold air mass [4]. This system interacted with a broader summer heat wave affecting the rest of the country, creating a stark contrast in temperatures across different U.S. regions [4].
While the mountain passes face freezing conditions and accumulating snow, other parts of the U.S. are managing extreme heat. The interaction between these two opposing weather systems is what created the rare timing of the snowfall during the transition to summer.
“A rare late-June snow event is covering parts of the northern Rockies with up to 12 inches of snow.”
The occurrence of significant snowfall in late June suggests a disruption in typical seasonal transitions. When extreme cold air masses penetrate deep into the northern Rockies while the rest of the continent experiences a heat wave, it indicates high atmospheric instability and a sharpening of temperature gradients across the U.S.
