Anchorage Daily News

Ten inches to a foot of fresh snow that looks great for snowboarding and snowmobiling could be setting a trap to get someone killed this weekend, avalanche professionals around the region are warning.

Even before the latest snowfall, said Debra McGhan, executive director of the North America Outdoor Institute in Wasilla, conditions in the area were getting dicey.

"On Feb. 1,'' she reported, the institute's Dan Dryden "counted over 10 recent avalanches in Hatcher Pass. The avalanches were on all aspects -- north, south, east and west. He skied up the west ridge of Microdot (Mountain) and encountered shooting cracks, a clear marker of snowpack instability. He reported hearing whoomping of a collapsing weak layer at approximately 3,500 feet.''

Upon digging a snow pit, Dryden only found the situation worse. There were multiple layers of dense, compact snow sitting on layers of weak, unconsolidated snow. These are prime conditions for creating the kinds of avalanches that send automobile-size chunks of slab roaring downhill.

"(And) now we have several new inches of snow as the icing on top of this mixture,'' McGhan said in an e-mail. "In layman terms, this is a lasagna recipe for avalanche. The (loose) depth hoar acts like ball bearings, and all it takes is a simple trigger like ... a snowboarder, skier or snowmachine to rip it loose and put everything in its path in peril.''

McGhan said anyone planning to recreate this weekend needs to be especially careful. She notes there have been more than 50 avalanche victims in the state in the past decade.

And it's not just Hatcher Pass that is dangerous at the moment.

The Chugach National Forest Avalanche Center is warning not only of the risks of human-triggered avalanches but of potential dangers of people being caught in runout areas by naturally occurring avalanches. The Turnagain Pass area has the same layer-cake problem that Hatcher Pass has.

Wind slabs, Chugach avalanche officials report, have formed "over the most recent layer of buried surface hoar that formed over the past two weeks (of cold). The weak layer is buried about 16 to 23 inches deep. This layer is fairly widespread in the Kenai and Chugach Mountains. Two other weak layers of buried surface hoar exist in isolated pockets approximately three to four feet down and four to six feet down.''

An avalanche triggered at such depths would likely be massive, but even a slide going only a foot deep can easily bury and kill someone.

Closer to Anchorage, conditions are equally dangerous in Chugach State Park, officials said.

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