Rising temperatures and rain will create dangerous avalanche conditions through the weekend in Southcentral Alaska, but officials say there is also concern that the weather pattern could break into older, deeper layers of snow — leading to larger and more unpredictable avalanches in coming weeks.
Backcountry travel is not recommended throughout the weekend, said Wendy Wagner, director of the Chugach National Forest Avalanche Information Center. Updates on conditions can be found at the avalanche center’s website.
A large, “scary-looking avalanche” released Thursday at Turnagain Pass on Tincan Proper, Wagner said. A group of skiers had been looking for avalanche warning signs and wind slabs as they skinned up the mountain that morning, but conditions seemed safe, one of the skiers wrote in a report published by the avalanche center.
The skier stepped back behind a rock pillar after hearing a loud noise. Then, an avalanche began sliding down the mountain, the report said. The avalanche was 2 feet at the crown and 5 feet deep.
“If I had been a few more paces out on the wind slab I likely would have been carried down the north chute 2000′ to the valley floor,” the skier wrote.
Wagner said the avalanche was concerning not only because of its large size, but also because no red flags were present.
“Just after Christmas we had a really significant warmup and even the ridge tops got so warm that it created what we call a melt-freeze crust on the surface all the way to the ridge tops,” Wagner said. “And that has now been covered with several feet of snow. But those crusts can do strange things — which is what we saw at Tincan.”
Several other wind slab avalanches were reported in the last few days, although Wagner said they were smaller.
Rain and wet snow could fall late Saturday and into Sunday around portions of Southcentral Alaska, said National Weather Service meteorologist Brandon Lawson. Temperatures Friday hovered around or above freezing near Anchorage and along the Turnagain Arm but began rising in the evening.
The higher temperatures began complicating avalanche conditions Friday, Wagner said. There was considerable danger up to 2,500 feet of elevation and there was a high risk of avalanches for people traveling in the alpine area. Areas near Portage and Seward will be especially dangerous because the heaviest precipitation is expected to hit there, according to the avalanche center’s forecast.
“There’s some concern that we could get some larger avalanches with the weather that could potentially break in some deeper, weak layers that aren’t everywhere, but as we found out yesterday, there could be some little booby traps out there that a bigger avalanche could be produced,” Wagner said.
“We have all the red flags for weather, we have heavy snowfall, we have strong winds and we have warming temperatures,” Wagner said. “So as long as this storm cycle persists, people should be well aware of avalanche paths. And this is everywhere, not just in our forecasts ... don’t go on a summer trail that has an avalanche path above it.”
“... If people heed the advice and everyone stays out of avalanche terrain, hopefully they’ll get overloaded and avalanche,” she said of the slopes. “And that’s a good thing if that happens on its own without people around.”