A weak, sugary snowpack is raising the avalanche danger in parts of the West, leaving slopes vulnerable to crumbling under the pressure of heavy snowstorms that also have lured skiers and snowmobilers looking for fresh powder.
Avalanches killed three people in Colorado over the weekend, including two who were skiing at resorts that were pounded with new snow. On Monday, an avalanche buried a man in Montana, but snowmobilers and skiers were able to quickly dig him out. In Wyoming, U.S. Forest Service officials warned backcountry enthusiasts to beware of dangerous conditions.
Avalanche forecasters say a weak base layer of snow, packed with large grains of ice that aren't well connected to each other, is plaguing parts of Colorado, Utah, Montana and California and could keep avalanche risks high for the rest of the season.
"This has the potential to be a pretty dangerous winter because of the foundation," Colorado Avalanche Information Center avalanche forecaster Scott Toepfer said Tuesday. "It may haunt us into the spring."
The Colorado Avalanche Information Center has recorded eight avalanche deaths around the West this season, with four in Colorado, three along the Wyoming-Montana border and one in Utah. There were 25 recorded last winter and 36 the season before.
All four Colorado deaths this winter happened within the last week following storms. A backcountry skier near the Snowmass ski area was trapped Jan. 18. Resort officials said one skier died after being caught in a small avalanche at Winter Park Resort on Sunday, and a 13-year-old skier died after being trapped Sunday on a closed area at Vail Mountain.
On Monday, rescuers reached a snowmobiler who took shelter in a snow cave after an avalanche trapped him and his brother over the weekend. Jordan Lundstedt, 21, of Fort Collins, made swimming motions to stay near the surface and dug himself out of the snow, but 24-year-old Tyler Lundstedt died after being buried under an estimated 2 to 3 feet of snow, said Mark White of Jackson County Search and Rescue.
The brothers' snowmobiles had gotten stuck, and they were on foot when the avalanche struck, either late Saturday or early Sunday, White said.
Jordan Lundstedt told rescuers the brothers had avalanche beacons, which led him to find his brother in the dark, but the slide stripped him of his other gear.
More than 100 slides have been reported to the Colorado avalanche center since Friday.
In Utah, avalanche dangers remained high on Tuesday across the northern mountains after two back-to-back storms brought the region its first significant snowfall of the season. Several feet of snow fell on the mountains through the weekend, adding dangerous layers atop older snow.
The instability can last days after a storm, Utah Avalanche Center Director Bruce Temper said.
"That's what makes it so dangerous because after the storm is over, it's just basic human nature to think when the storms are finished, the danger is finished, but the snowpack is just teetering on the edge," Temper said. "It's just waiting for someone to give it a thump and it'll just come on down."
New gear, new technology and backcountry ski and snowboard films have lured more and more powder hounds to seek fresh snow after storms.
This season, icy base layers have proven a weak matrix for snow dumps to rest on. If more than a foot of snow piles up quickly, like it did in Colorado last weekend with gusts reaching 70 mph, the layers of snow can give way, Toepfer said.
"If you built a foundation of your house on potato chips, you get a wind storm and your house is going to blow over," Toepfer said.
In Colorado, north-facing slopes that don't see as much sun and slopes at 30- to 40-degree angles are prime avalanche country.
Officials at the Utah Avalanche Center were warning people to remain out of much of the backcountry. More than a dozen avalanches have been reported just since Sunday, but Utah has only had one slide-related death this season.
Jamie Pierre, a world record-holding professional skier who once famously jumped off a 255-foot cliff, died Nov. 13 in the mountains near Salt Lake City while on a steep slope at Snowbird Ski and Summer Resort. The resort wasn't yet open and had not begun avalanche control.
Avalanche deaths are more common in the backcountry than at ski resorts. Out of about 900 avalanche deaths nationwide since the 1950-1951 winter, 32 were within terrain that was open for riding at ski resorts, according to the center.