Forecasters are warning of a heightened risk of avalanches in Southcentral Alaska, from the Anchorage Hillside to Turnagain Arm and the Kenai Peninsula.
People traveling in the mountains, as well as on trails below, need to be cautious, the forecasters said.
The Chugach National Forest Avalanche Center issued a warning Friday morning, as a spring storm blew into the region. New snow in the mountains was expected to overload an already weak snowpack, causing natural avalanches and making it likely for a person traveling in avalanche terrain to trigger a slide.
The atmospheric river event could bring as much as two feet of snow to Girdwood and Anchorage’s Hillside late Friday, said Andrew Schauer, the avalanche center’s acting director. Farther south near Portage and Seward, he said, it could be between three and five feet.
High wind was expected to add to the instability, Schauer said.
“The weight of a person on top of that weak snowpack could be all that's needed to trigger a really big avalanche,” he said.
The storm is set to subside after Friday, but Schauer advised people not to travel in avalanche terrain through the weekend.
“That's the kind of time frame when we see bad avalanche accidents happen, when the weather is a little bit nicer a day or two after a dangerous storm, especially when we have these layers of snowpack like we do now,” he said.
The Chugach National Forest avalanche warning extends through Sunday morning.
To the north, in Hatcher Pass, forecasters have seen a string of avalanches over the past two weeks. Since April 15, the snowpack in the area roughly doubled, said Tim Rogers, lead forecaster for the Hatcher Pass Avalanche Center.
“We got up to four feet of snow, over that probably,” Rogers said. “Several inches of snow-water equivalent. And that created new avalanches, as well as overloading buried weak layers from a season-long, stale snowpack that was extremely weak and faceted.”
On Wednesday, Rogers and two other forecasters found themselves caught in an avalanche, after unintentionally triggering a slide by moving too close to a cornice overhanging a ridge. The avalanche ran 400 to 600 feet and carried two skiers. The forecasters reported no injuries, and all of their gear was accounted for, though “a bewildered sense of shock and awe was shared.”
With the start of spring, Rogers said, the Hatcher Pass center has stopped issuing its regular forecasts. The center will continue to do general information bulletins on Fridays and Mondays.
“Conditions are super dynamic,” he said. “You're really likely to encounter just about every avalanche problem out there. New snow, old snow, warming, cold. You know, it still feels like winter on northerly aspects, and it's very warm in the afternoons on sunny days.”
In general, the start of spring is a particularly dangerous time for avalanches, said Schauer, with the Chugach center. The warmer temperature and rain have weakened the snowpack further, he said.
That’s created an elevated risk for backcountry mountain travelers and those on seemingly mellower trails below, Schauer said. A recent video on Facebook showed an avalanche running over a dirt trail near Portage as a family hiked nearby.
“We had that avalanche incident last weekend that involved five hikers on Peak Three (near Anchorage) or the near-miss out in the Byron Valley near Portage,” Schauer said. “But there's all these hiking trails that are melting out that are exposed to major avalanche threat, and this is the time of year when those accidents happen.”
He advised people to check out their local avalanche warning center’s websites before planning any travel through the backcountry.
