New snow is adding further load to existing slab avalanche conditions. Above 9000 feet, the chance continues for persistent slab to be triggered by a single rider or skier. Wind slab avalanches could be also human triggered above 7500 feet. These slabs will increase in size and sensitivity today as new soft slabs also develop. Avalanches are unlikely below an elevation of 7,500 feet. Careful snowpack evaluation, cautious route finding and conservative decisions are essential for safe travel in avalanche terrain.
At the upper elevations large slab avalanches with depths to three feet could be human triggered on northerly aspects. These large slabs will likely be hard and have high crowns. Beware that a few tracks are not an indication of stability for this type of hazard.
Recently formed wind slabs and new soft slabs currently forming during this storm event could be triggered today. The newer wind slabs could have depths as large as a foot by the end of the afternoon with a slight potential for older slabs to trigger with depths of an additional two feet.
( Discussion is generated from the previous day's afternoon forecast. )A winter storm warning is in effect through Saturday morning. Snow is to develop overnight and continue through Friday and into the weekend. Precipitation will start with cooler temperatures tonight and then be followed with warmer temperatures on Friday with mountain highs in the mid twenties expected. Approximately ten inches of snow is expected to fall by 5pm Friday. Southwest winds with twenty to twenty five mile per hour averages are to occur through this period. Friday evening and night winds are to increase to 25-35 mph averages and snowfall intensity is also to increase. The general avalanche hazard is expected to remain Considerable above 9000 feet, Moderate from 7500 feet to 9000 feet and Low below 7500 feet. The chance to trigger existing deep slab avalanches and wind slab avalanches with maximum depths to five feet will continue. The avalanche danger is to slowly increase during the day as expected gradual loading increases the sensitivity of these existing slabs and starts to create new wind slabs on existing snow surfaces. The rate and timing of this increase in danger will depend on the actual amount and timing of new snow and wind. Check updated information in Friday's morning advisory.
