Avalanche conditions remain dangerous. Yesterday, three human triggered slides were reported, and one resulted in a full burial. Companion rescue was successful, and only minor injuries were sustained. Skiers and riders venturing into steep, wind loaded terrain could trigger small to large wind slabs at the mid and upper elevations. Large to very large persistent slab avalanches also remain a threat. While the abundant recent snowfall is very enticing, it is not worth risking your life. Great skiing and riding can easily be found in conservative terrain.
Sustained snowfall and southwesterly ridgetop winds have formed wind slabs in leeward terrain. At the mid and upper elevations, skiers and riders could trigger these slabs with depths of one to four feet in steep, wind loaded terrain.
A few breaks in cloud cover occurred yesterday, and a very large natural avalanche on Pyramid Peak was reported. This slide occurred recently, had an estimated crown depth of six feet and it connected three separate drainages. A skier also remotely triggered a very large avalanche on the Gros Ventre landslide, which failed on well-developed facets. In the mountains, similar avalanches could be triggered by backcountry travelers or step down from the release of a wind slab. At the lower elevations, persistent slab avalanches could fail on large grained facets near the base of the snowpack.
Skies will be partly to mostly sunny on Monday. This arctic air mass remains weakly unstable. Isolated to scattered snow showers are possible over the higher elevations. Temperatures will drop below zero tonight and rise into the teens and 20s. Winds will remain light and variable. Slabs formed by southwest winds during the most recent storm cycle continue to be a hazard on steep wind-loaded avalanche prone slopes. These slabs could be triggered by skiers and riders with depths to four feet. Slab avalanches can also be triggered by humans on persistent weak layers. These slabs could be 2 to 6 feet deep. These dangerous persistent slab avalanches are most likely to be triggered in areas that had a shallow snowpack with poor snow structure at the end of January. In the Teton Range these areas can be found at the lower elevations and in the northern portion of Grand Teton National Park. These areas are prevalent in the Togwotee Pass area below an elevation of 10,000 feet and up to even higher elevations on the east side of the Continental Divide. These areas can be found in most of the Greys River area and are prevalent in the eastern portions of this forecast zone. A careful assessment of the snowpack and conservative terrain choices are essential for snowmobilers and skiers who recreate in avalanche terrain. The general avalanche hazard is expected to be moderate below an elevation of 7,500 feet and in some areas with a deeper snowpack. The hazard will be considerable in areas where recent new snow lies upon a snowpack with poor snow structure.
