Tetons

Dangerous avalanche conditions exist as the general snowpack structure is upside-down with a denser slab of snow over a less dense layer of weak snow grains. At the mid and upper elevations on avalanche-prone terrain, it is likely for skiers and riders to trigger large persistent slab avalanches one to three feet deep. Since these persistent layers lie beneath a thick slab of snow, it may be hard to detect the hazard without assessing the snowpack structure, and old tracks should not be trusted. At the lower elevations, where there is only a few feet of snow, which experienced above freezing temperatures for 24 hours, avalanches are unlikely except for isolated pockets of deeper snowpack on steep slopes. This type of avalanche problem is best managed by terrain assessment and safe travel techniques of only exposing one person at a time. Backcountry travelers should evaluate steep slopes carefully and anticipate the potential consequences of triggering a large slab avalanche.

Christmas day will be dry. Expect skies to be clear above areas of morning valley fog. Clouds will increase in the evening. Temperatures will be inverted. The overnight lows are expected to be near or below zero in the valleys and in the low teens in the mountains. Daytime highs will rise into the 20’s.Avalanche conditions remain dangerous on steep slopes above an elevation of 7,500 feet where the general avalanche hazard will be considerable. Large slab avalanches up to three in depth have recently failed on a persistent weak layer and can be triggered by the weight of a single person. These killer slabs could be triggered by the first person to cross a slope or after a slope has been crossed multiple times. Assess terrain carefully and make conservative choices. The general avalanche hazard will be low below an elevation of 7,500 feet.