Strong winds and new snow are increasing the avalanche hazard and creating dangerous avalanche conditions. The higher elevations have received up to a foot of new snow with over an inch of moisture. Winds are gusting to near 60 miles per hour on the summits. The new snow has fallen upon weak old snow layers and hard crusts. At the upper elevations natural avalanche activity is possible and human triggered avalanche are likely. Loose snow sloughing on steep slopes above cliff areas and terrain traps could also be a hazard. Careful evaluations of terrain and snow stability are essential for safe travel in avalanche terrain. These hazards extend downward into the upper portion of the mid elevations, but to a lesser degree. The avalanche hazard is significantly lower below an elevation of 8,000 feet.
At the higher elevations strong southwest winds have created wind slabs up to two feet in depth on leeward aspects. In places these slabs lie upon slick crusts or weak layers of faceted snow. There are likely to be steep slopes where these slabs can be easily triggered by humans.
The National Weather Service has issued a Winter Storm Warning through 11 AM on Saturday. A strong Pacific weather system will bring moderate to heavy snowfall overnight. This system will be followed by a cold front which will bring another round of snowfall Saturday morning. Overnight lows in the mountains will be in the low teens, and temperatures are not expected to substantially increase during the day. Strong southwesterly ridgetop winds will veer to the northwest at 20 to 35 miles per hour. The general avalanche hazard is expected to be Considerable on Saturday. Strong winds and abundant snowfall will combine to form winds slabs on leeward slopes. In steep, wind loaded terrain at the higher elevations, skiers and riders are likely to trigger these slabs to depths of one to three feet. Natural avalanche activity will also be possible. A cautious approach to terrain management along with conservative decision making will be mandatory for safe travel in and below avalanche terrain.
