The next storm has begun to impact the area. A Winter Storm Warning has been issued by the National Weather Service. New snowfall and strong southwest winds will continue to add to recently formed wind slabs as well as further load deeper weaknesses in the snowpack, allowing for the possibility of large to very large avalanches to occur. By this afternoon, skier or rider triggered avalanches will become likely and natural avalanches will be possible at all elevations. Make conservative decisions with regards to backcountry travel plans today, watch for areas of wind loading and remember that the danger will increase this afternoon.
Southwest winds and expected new snowfall today will add to recent snow to form wind slabs in steep leeward avalanche terrain. These slabs will increase in size and sensitivity and could have depths to one foot at higher elevations this afternoon.
Much of the Togwotee Pass forecast zone has a poor snowpack structure. In those areas newer snow lies upon a weak base of well-developed faceted snow. Other persistent weak layers in areas where the snowpack is deeper include buried layers of surface hoar and near surface faceted snow. Large slab avalanches with depths from 1 to 3 feet could be triggered by the weight of a single person on these problem layers. The sensitivity of these slabs will increase as they are further loaded by new snow.
( Discussion is generated from the previous day's afternoon forecast. )Snow will return late tonight and continue through Wednesday and Wednesday night. The heaviest snowfall is expected from the mid afternoon through midnight. Over a foot of snow is expected by sunset. Southwest winds are to have averages between twenty and thirty miles per hour. Temperatures in the mountains are to rise from the low to upper teens. The general avalanche danger is expected to be Considerable in the morning at all elevations and could increase to High at the upper elevations of the Tetons during the afternoon if significant precipitation occurs. Snowfall and strong winds will form sensitive wind slabs that could fail as shallow slabs on today’s snow surfaces or involve the last few days snowfall to depths of one to three feet. The new snow will also further load the persistent weaknesses that could be triggered by the presence of a person or release once a wind slab is initiated. Look for signs of wind loading and make conservative terrain choices to avoid the chance of triggering deeper snowpack issues that could result in large and dangerous slides.
