Tetons

A cold front brought very strong winds to the Tetons on Friday and transported available snow onto leeward slopes. These winds were not isolated to the higher elevations, and shallow pockets of wind slab formed in leeward terrain and in unusual locations. At the mid and upper elevations, skiers and riders could trigger these small slabs on steep, wind loaded slopes. Backcountry travelers still have some potential to trigger large persistent slab avalanches. Evaluate the snowpack often, and don’t assume that one snow pit will give you a representative picture of the avalanche hazard. At the lower elevations, skiers and riders might be able to trigger an isolated pocket of shallow slab in very steep terrain.

Cloud cover will increase overnight as the first in a series of Pacific disturbances approaches the region. Light to moderate snowfall from this system will develop by noon. Overnight lows in the mountains will be in the single digits before rising into the mid-teens in the afternoon. Westerly ridgetop winds will back to the southwest and increase to 15 to 25 miles per hour during the day.The general avalanche hazard is expected to be Moderate on Sunday above 7,500 feet. Friday’s wind event created pockets of wind slab and loaded existing weak layers of faceted snow that developed in November and early December. As Saturday’s fatal avalanche event illustrates, human triggered avalanches remain possible. The substantial amount of spatial variability associated with both wind slabs and persistent slabs requires a cautious approach to terrain management. Below 7,500 feet, backcountry travelers might be able to trigger an isolated pocket of slab in very steep terrain.