Backcountry travelers could trigger wind slabs in steep, wind-loaded terrain or deeper persistent slabs that lie upon buried weak snow near the ground. Strong winds will continue to load the wind slabs although little snow has fallen overnight. Moderate danger indicates that these slabs require the weight of a backcountry skier or rider to initiate them and that they are not likely to release naturally. The snowpack is still weak and careful evaluation of the snowpack and terrain is necessary today. Yesterday a snowboarder died on the Pyramid path to the south of Jensen Canyon in the Teton Range where significantly more snow has fallen.
Skiers and riders could trigger new and recently developed soft wind slabs on all aspects and elevations. At the higher elevations, these slabs could have depths to two feet and fail on old hard surfaces or density breaks within the recent snowfall. Beware of steep terrain with obvious areas of wind loading.
Above 7,500 feet, hard slabs with depths to four feet lie upon persistent weak layers of faceted snow. Since Wednesday night, around one and a half to two inches of snow water equivalent have been added to the snowpack. Large triggers, such as groups of people, may be needed to trigger one of these slides. However, the weight of a single skier or rider could still act as a trigger.The release of a wind slab could also step down to these basal facets. If triggered, these slabs will carry high consequences.
( Discussion is generated from the previous day's afternoon forecast. )Another system is to bring snow tonight and Wednesday. The National Weather Service has issued a winter weather advisory. A foot of new snow is possible at the higher elevations by Thursday and this snowfall is to be accompanied by strong west winds. Mountain temperatures are to reach near twenty degrees on Wednesday. The general avalanche hazard is expected to be Considerable at the mid and high elevations on Wednesday. By the afternoon, the hazard could raise to HIGH above 9000 feet as natural avalanche activity becomes likely from the new snowfall and strong west winds. The avalanche problems includes new and recently formed wind slabs to 3 foot depths as well as persistent weaknesses which could result in large dangerous slabs to six foot depths in the Tetons or lesser depths in the Southwest Trails or Togwotee Pass areas. Below 7500 the avalanche hazard is expected to be Moderate in the morning and could rise to Considerable in the afternoon depending on snowfall amounts at the lower elevations. Given the amount of loading over the last week and the forecasted heavy snowfall to come, cautious route finding and decision making are essential during this period. Known avalanche paths should simply be avoided and safer, low angle, conservative terrain should be the focus of backcountry travelers.
