Weak layers of faceted snow persist within the snowpack at the higher elevations and comprise the bulk of the snowpack in areas with a shallow snow cover. Yesterday a skier in the Snake River Range remotely triggered an 18 inch deep slab avalanche on a buried layer of surface hoar. Skiers in the Teton Range experienced a large collapse that failed on depth hoar. At the higher elevations persistent weak layers may still be capable of failing due to the weight of a person. Slab failure may be more likely to be initiated on steep slopes by a larger triggers such as snowmachines and skiers or riders who hit a shallow weak spot in the snowpack. Avalanches are unlikely below an elevation of 7,500 feet except on isolated terrain features.
In steep terrain at the mid and upper elevations humans could trigger small to large slab avalanches one to three feet in depth. Avalanches are unlikely below an elevation of 7,500 feet.
( Discussion is generated from the previous day's afternoon forecast. )Dry conditions will continue into Saturday. Winds will slowly increase ahead of an approaching Pacific cold front and upper level disturbance. Temperatures inversion will continue overnight but could begin to mix out during the day as this front approaches. Chances for snow will increase in the south during the afternoon and will reach the other areas before midnight.The general avalanche hazard will continue to be moderate at the mid and upper elevations and low below an elevation of 7,500 feet. At the mid and upper elevations persistent slab avalanches one to three in depth could be triggered by humans on steep avalanche prone slopes. Avalanches are unlikely at the lower elevations.
