Key Points
- Winter Storm Warnings issued for high elevations in Idaho, Montana and Wyoming.
- Up to 16 inches of heavy wet snow expected above 6,500 feet.
- Yellowstone and nearby mountain routes could experience hazardous travel.
- Temperatures forecast to drop 20 to 30 degrees within days.
A rare winter storm warning has been issued across parts of Idaho, Montana and Wyoming, bringing the unusual possibility of heavy snowfall during the final days of June.
Forecasters say higher elevations above approximately 6,500 feet could receive between 4 and 16 inches of heavy, wet snow, while isolated mountain peaks may see even greater accumulations. Strong wind gusts of up to 30 mph are also expected, creating difficult travel conditions across mountain passes and backcountry routes.
Snow Returns During Peak Summer Travel
The storm arrives just as millions of travelers prepare for summer vacations and Fourth of July trips to some of the western United States' most popular national parks.
Roads leading to Yellowstone National Park, Glacier National Park and Grand Teton National Park could experience slushy conditions, reduced visibility and temporary travel disruptions, particularly across higher mountain passes.
Campers, hikers and outdoor enthusiasts have also been advised to prepare for rapidly changing weather conditions, including near-freezing temperatures and an increased risk of hypothermia at higher elevations.
Unusual Weather Pattern
Winter storm warnings during late June remain uncommon, even in the northern Rocky Mountains.
Meteorologists attribute the event to an unusually cold Pacific weather system pushing snow levels much lower than normal for this time of year. Some valleys that recently experienced temperatures in the 80s and 90s are expected to cool by 20 to 30 degrees within just a few days.
The combination of heavy wet snow, strong winds and saturated ground could also increase the risk of fallen trees, localized flooding and difficult driving conditions in mountainous areas.
Travelers Urged to Prepare
Weather officials recommend delaying unnecessary travel through higher elevations until conditions improve.
Those who must travel are encouraged to carry emergency supplies including warm clothing, blankets, food, water, flashlights and tire chains where appropriate. Campers are also advised that accumulating snow can damage tents and outdoor equipment even during the summer season.
The warning highlights how rapidly mountain weather can change, even as much of the United States experiences typical summer temperatures.
