At the upper elevations, approximately two feet of snow has fallen since Saturday afternoon. Strong southwest winds have loaded the snow onto leeward aspects. Skiers or riders can easily trigger wind slabs today in very steep terrain with depths to three feet above 7500 feet and one foot below that elevation. The chance also continues for older buried weakness to fail and large avalanches could be triggered that are likely to have severe consequences. Evaluate the snowpack to avoid areas of wind loading and make conservative decisions regarding areas where the persistent weak layers remain a concern.
Soft slabs formed by southwest winds could be triggered by humans on steep wind loaded starting zones. These slabs could increase in sensitivity today in areas where they are weakened by periods of direct sunlight and warming temperatures.
New snow and winds have increased the load on persistent weak layers. At higher elevations, slabs could fail on faceted snow and/or crusts buried by the last storm on February 2nd and have depths of two to four feet. At lower elevations, where the snowpack is shallow and wrought with weak faceted snow, older layers may fail near the ground with depths to two feet.
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.
