Kent May skied Turnagain Pass on Friday and felt the snowpack deflate.
About 100 feet away, snow fell from the mountain and triggered another avalanche farther down and then a third.
"It's one of those things where you know not to go further," said May, of Girdwood, who was skiing with five others. "But we were able to see the red flags that the conditions were worse than we thought and to change our travel plan accordingly."
With snow expected to pummel the eastern Turnagain Arm area into Sunday and worsen already-tender backcountry conditions, an avalanche warning was issued Saturday for the Kenai and Western Chugach Mountains. The warning is in effect until 5 p.m. Sunday. It does not include developed ski trails or highways.
The National Weather Service forecast up to 30 inches of snow for the backcountry area.
If the storm hits as hard as forecasters predict, it could double the shallow 30-inch-deep snowpack on Turnagain Pass, said Graham Predeger, avalanche forecaster with the Chugach National Forest Avalanche Information Center. The mountains are typically covered with 64 inches of snow at 1,880 feet around this time, he said.
"We have a really weak foundation to our snowpack, and that's been set up due to unusually cold temperatures and just not a lot of snow," Predeger said.
The added pressure from fallen snow will only destabilize conditions.
On Friday, four avalanches were reported, one that resulted in the death of a dog that ran down Tincan Peak before it collapsed. There were no human deaths or injuries reported as of Saturday evening.
Like May's experience, the avalanche that killed the dog was also caused by the weight of people on the mountain. The warning issued by the Chugach National Forest Avalanche Information Center says natural avalanches are likely and human-triggered slides "are certain."
"That's some pretty strong wording coming from our office," Predeger said. "We rarely use wording that strong unless we're absolutely sure things are going to go off."
Avalanche warning signs include shooting cracks in the snow, he said. You should also stay away from areas where you suspect a avalanche has already occurred.
If in the middle of an avalanche, "the best thing you can do is fight like hell to stay at the surface," Predeger said.
On the road end, Matt Murphy, avalanche specialist with the Department of Transportation, said his crews will evaluate the situation as it develops.
"I just won't know until I see what the storm does."
When avalanche danger is imminent, DOT uses a 105mm howitzer for avalanche prevention. It looks like a cannon and fires a bullet up to the top of the mountain, causing an avalanche.
"Basically the idea is to trigger an avalanche intentionally and under a controlled environment," Murphy said.
While the eastern Turnagain Arm area prepares for the storm, Anchorage will be spared, according to the National Weather Service.
The city received less than one inch of snow Saturday. Scattered rain and snow showers are forecast for Sunday, said Bill Ludwig, meteorologist with the National Weather Service.
"We're expecting the mountains to protect us from the main snowfall," Ludwig said.
Reach Tegan Hanlon at firstname.lastname@example.org or 257-4589.