The snowpack is mostly stable, however a layer of surface hoar buried on January 16 continues to be a persistent weak layer at the mid and upper elevations. Skiers have triggered hard slabs on this layer in isolated areas. The most recent event occurred on Thursday in the northern portion of the Teton Range on a northeast aspect at an elevation of 8,600 feet. Strong northwesterly winds, associated with a passing cold front yesterday afternoon, redistributed available snow along exposed ridge crests. Avalanches at the lower elevations are not expected today.
Buried surface hoar lies in the snowpack six to eighteen inches below the snow surface. In isolated areas, particularly in colder protected terrain that has not been tracked, skiers and riders might still be able to trigger hard slabs failing on this weak layer.
Three disturbances embedded in the westerly flow will impact our region during the next three days. The first will bring three to six inches of new snow the higher elevations of the Teton, Salt River and Wyoming Ranges overnight. This first event will taper off midday on Monday with only very light snowfall expected in the afternoon. Temperatures will warm into the teens and 20s. Winds will be westerly at 20 to 25 with gusts to 30 miles per hour along the highest ridge crests.The new snow will fall upon slick crusts, surface hoar and near-surface faceted snow. Shallow loose snow sluffs will likely release from upper elevation cliff areas. Shallow pockets of new soft slab less than a foot deep will be formed by west winds and will be sensitive to human triggers. Some hazard will remain for humans to trigger shallow persistent slabs up to a foot in depth in isolated areas. The general avalanche hazard is expected to be LOW at all elevations, however loose snow sluffs and small pockets of new soft slab could knock people over in upper elevation cliff areas.
