Strong winds and new snow are increasing the avalanche hazard. The mountains have received up to 10 inches of new snow with about an inch of moisture. Wind gusts to near 91 miles per hour were recorded this morning at the Mt. Coffin weather station at an elevation of 10,870 feet. Avalanches are unlikely below an elevation of 8,000 feet.
At the upper elevations strong west to southwest winds will be forming pockets of wind slab up to 18 inches in depth. Up there these slabs lie upon slick crusts or weak layers of faceted snow. There are could be steep slopes where these slabs can be triggered by humans.
( Discussion is generated from the previous day's afternoon forecast. )A low pressure trough with embedded disturbances will dig southeast through the region resulting in mountain snow and a mix of rain and snow at the lowest elevations. One of these disturbances will cross the region early Friday morning and provide a brief period of moderate to heavy snowfall before sunrise. Light snow with little accumulation is forecast during the day. Another disturbance will bring heavier snowfall Friday evening and into Saturday morning. Temperatures will be in the teens and 20s in the mountains and in the 20s and 30s in the mountains. Southwest winds will increase to 25 with gusts to 50 miles per hour.As new snow depths and winds increase so will the avalanche hazard. Pockets of wind slab will form on hard crusts and persistent weak layers of faceted snow. Due to the surface distribution variabilities in these old snow surfaces some of these wind slabs may be very sensitive to human triggers while other may not. Total snow depths are shallow. Getting caught in a small slide on a very steep slope could have serious consequences. If the weather forecast verifies the general avalanche hazard is expected to be LOW and on the increase. Increased snowfall and winds could quickly increase the hazard to MODERATE.
