Dangerous avalanche conditions exist. A series of storm systems has brought periodic snowfall to the area since Tuesday. During this time, over two feet of snow has fallen in the Tetons. Winds that have been strong at times have varied from the south-southeast to the northwest. Caution is advised as the new and recently fallen snow could be easily triggered as soft slabs in steep leeward terrain by backcountry enthusiasts. Once triggered, such an event could cause deeper instabilities in the snowpack to fail, resulting in large to very large avalanches. The size and sensitivity of triggering these avalanche events is greatest at the mid and upper elevations, however human triggered low elevation slides remain possible.
Skiers and riders could trigger recently formed slabs in steep wind loaded terrain. These slabs could fail on density breaks within the last few days snowfall or on hard sun crusts or faceted snow that was buried on Tuesday with depths to thirty inches at the higher elevations and to eighteen inches at the lower elevations.
During the last several days, over two inches of snow water equivalent has been added to a snowpack that has buried persistent weak layers. Above 7,500 feet, this load has increased the likelihood of these weaknesses failing to human traffic, or more likely, following the release of a wind slab. Once triggered, these slabs could have depths of two to four feet. The snowpack is comprised of mostly faceted snow below 7,500 feet, where skiers and riders could trigger recently fallen snow that could also be considered a persistent slab with depths to eighteen inches.
Skies are to clear this evening and be mostly sunny and dry on Tuesday. Temperatures are to be much colder and mildly inverted in the morning with mountain lows in the single digits followed by highs in the teens. Northwest winds are to have fifteen to twenty mile per hour averages during the day which will keep ridge-tops cool, while sunlit calm areas have the potential for rapid warming. The general avalanche hazard will continue to be Considerable above 7500 feet and Moderate below that elevation. The recently formed slabs have gained some strength and due to time and their nature, will behave less like new winds slabs in the days to come. They will continue to be dangerous and sensitive to human presence as their behavior takes on characteristics primarily of persistent slabs. In some areas, the slabs lie above sun crusts and surface hoar while in others, slabs lie over a very weak snowpack. Predicting where these weakness make the snowpack unstable enough to slide by a persons weight is very difficult as many slopes will not fail while others may release remotely. Restraint and patience are key in managing this hazard. Slab depths could reach three or possibly four feet at higher elevations and eighteen inches at lower elevations.
