In the Teton Range some very large slab avalanches with crowns to 8 feet in depth released naturally on Sunday night. These slides occurred during an intense precipitation event that was accompanied by strong westerly winds. These destructive avalanches are believed to have failed on a persistent weak layer that formed in December and lies above a crust that formed in late November. In the afternoon a skier was caught and swept down a steep couloir in Granite Canyon but not buried or injured. Natural avalanche acitivty is less likely today. Dense surface slabs and very dangerous deep persistent slab avalanches could be human triggered. Close calls involving skiers have occurred during the previous two days. Expert route finding skills and conservative terrain choices are essential.
At the mid and upper elevations dangerous persistent deep slabs up to six feet in depth could be human triggered on a variety on aspects. These slabs could fail due to the weight of a snowmobile or a single person who encounters a shallow weak zone. These slabs could propagate and run long distances and are likely to carry severe consequences to anyone involved.
Dense wind slabs formed by strong westerly winds could be human triggered to depths of two feet and once triggered could step down and become a large destructive deep slab avalanche.
Skies will continue to be mostly to partly cloudy with some light snowfall in the mountains. Accumulations will generally range from a trace to two inches. Temperatures will be in the teens and 20s. Winds will be from the west-northwest at 20 with gusts to 30 miles per hour.Today’s remotely triggered slide in the Teton Range and widespread natural avalanche activity two evenings ago indicate that a persistent weak layer is still capable of producing dangerous slab avalanches. Due to the size of the recent avalanches and their distribution throughout our terrain a cautious approach to avalanche prone slopes is recommended. Large slab avalanches two to six feet in depth could be triggered by riders or skiers on a variety of aspects. The general avalanche hazard is expected to remain CONSIDERABLE on Wednesday.
