JACKSON, Wyo. — The Bridger-Teton Avalanche Center has issued an avalanche warning that will remain in effect through 10 p.m. on Saturday, Jan. 13. Travel in avalanche terrain is not recommended, as natural and human-triggered avalanches large enough to bury people are almost certain to occur, according to the warning.
According to the Backcountry Avalanche Forecast, a generally weak snowpack is being rapidly loaded by continued snowfall and strong winds, and will stress a historically weak snowpack making natural and human triggered avalanches likely.
The Backcountry Avalanche report states that since Jan. 4, three to four feet of new snow containing nearly three inches of moisture has fallen on weak snow surfaces formed during one of the driest Decembers on record. Avalanches involving this interface are expected to occur naturally and will be very sensitive to human triggers. Slides can be initiated remotely, meaning from flat terrain that is above, beside or below an avalanche starting zone. Avalanches on this layer could be hard or soft and have depths up to three feet. This avalanche problem is widespread at the mid and upper elevations and extends into the lower elevations on certain aspects.
Snow that started falling on Thursday, Jan. 11, has been impacted by strong winds and has formed soft slabs on steep leeward slopes. This surface instability will be more obvious at higher elevations, where there should be signs of wind-loaded snow and will be less apparent at lower elevations where wind loading will be less obvious. These slabs could have depths to 18 inches and once initiated are likely to pull out the underlying snow lying on the weak persistent layers, according to the Backcountry Avalanche Forecast.
The Bridger-Teton Avalanche Center reports that avalanches could also involve deeper weak snow near the base of the snowpack. This avalanche problem exists due to the weak layers formed during the extended drought in November. It has proven to be mainly dormant but added load due to recent snowfall and wind-loading could provoke an avalanche on this layer. The layer can be found at the mid and upper elevations with a northerly tilt.
According to Buckrail’s Meteorologist Alan Smith, backcountry travelers should be prepared for significant avalanche danger, as the snowpack structure leading up to this cycle is in poor shape. Check in with the Bridger-Teton Avalanche Center for the latest conditions.
