Much of the United States is firmly in winter’s grasp, with ice storms snarling the nation’s mid-section. But in more mountainous areas, from the Sierras and the Rocky Mountains to New England, the risk of avalanche is dangerously high.
The situation in the southern stretches of the Rockies has been particularly precarious, with four fatalities in the past week, including two men who were buried in-bounds by an avalanche on lift-served terrain at Taos Ski Valley in New Mexico. Over the past month, eight people have been killed in avalanches from Montana to New Mexico, including three snowmobilers and five skiers.
In the case of one avalanche on January 5 in southwestern Colorado, slides were triggered by a group of skiers participating in an avalanche safety class. Six skiers in the group were caught in the snow and one was buried and killed.
Reports filed so far for the fatal avalanches from the past month have one thing in common: a weak layer of coarse-grained or “faceted” snow near the ground that can give way, sending layers of snow on top of it careening downhill. Early season snows followed by relatively persistent cold temperatures can help to create such weak layers that may then become dangerous, especially when wetter, heavier snow falls on top of it.
“Today, you can trigger a large and dangerous avalanche,” writes the Colorado Avalanche Information Center’s Matt Huber in his latest avalanche forecast for the Aspen area, where a backcountry skier was buried and killed Monday. “Over the past week, heavy snowfall and strong southwest winds put a heavy load on a weak snowpack.”
According to Avalanche.org, which is a partnership of the American Avalanche Association and the federal National Avalanche Center, considerable avalanche danger can be found in the backcountry of Washington state, California’s eastern Sierras, much of Colorado’s mountains and popular parts of Wyoming, Montana and Idaho. Moderate avalanche danger is also reported in New Hampshire, while the most dangerous conditions can be found in the mountains to the west and south of Salt Lake City in Utah.
This winter is on the same pace as the previous season, in which there were a total of 25 avalanche-related fatalities in the United States, more than double the amount of the 2016-2017 season.