Human-triggered avalanches are likely this weekend from Girdwood to Seward despite the seemingly calm weather, according to a bulletin issued Friday by the Chugach National Forest Avalanche Information Center.
Anyone traveling in the backcountry should use caution and avoid terrain steeper than 30 degrees, the bulletin said. The warning begins early Saturday and ends Sunday night. It includes Turnagain Pass and the Kenai and western Chugach mountains. Similar conditions may exist in surrounding areas, the bulletin said.
“If you are planning on getting out this weekend, be aware that we are dealing with some serious issues snowpack-wise, and now is not the time to push it into steep terrain,” the avalanche center wrote in Friday’s forecast.
Up to an inch of snow could fall Friday at higher elevations, but calm weather is predicted through the weekend. A foot of snow fell earlier in the week at higher elevations near Turnagain Pass, which made the snowpack more unstable, avalanche forecasters say.
The conditions now — unstable upper layers and weak layers toward the bottom of the snowpack — could cause large avalanches, forecasters say.
The avalanche center said natural and human-triggered avalanches were reported in the mountains four days in a row this week.
A large natural avalanche along the Seward Highway earlier this week buried a section of Alaska Railroad track just south of Girdwood. Early Tuesday, a freight train struck the debris, derailing two locomotives and partially derailing a third.