Wind slabs have been forming at the upper elevations over recent days. These slabs could fail with varying depths and several have occurred in the last two days. Although most of these slabs have had relatively small crown depths, backcountry travelers are encouraged to remember that initially small slides can pick up significant amounts of snow in runs that are steep and long such as couloirs. Additionally. small slides can quickly sweep people into or over cliff areas and rocks in exposed terrain. Deep slab instabilities continue to be a concern at the mid and upper elevations where larger triggers such as a moving wind slab or snow machine have some potential to trigger large avalanches. Avalanches are unlikely at the low elevations except for in isolated pockets.
At the upper elevations wind slabs formed by west-northwest to southwest winds could be triggered on steep terrain features. These slabs are failing on recent density breaks and could have depths of 6 inches to 2 feet deep and could become a significant hazard in very steep chutes, and above cliff areas and terrain traps.
Some potential continues for deep hard slab avalanches to occur. Although the likelihood for these avalanches to be triggered is low the consequences of triggering a slab avalanche 3 to 7 feet deep could be fatal. These dangerous slabs are most likely to fail when a larger impact such as a snow machine or a moving surface slab impacts a thin, weak spot on a slope.
Snow is to fall through most of the night. The heaviest snowfall is expected by midnight. By sunrise up to ten inches of snow could have fallen since noon today. Winds are to veer from the southwest to northwest before 8am with averages between ten and twenty miles per hour. Temperature are to drop to the low teens overnight and rise into the mid-twenties during the day. The general avalanche hazard is expected to be moderate above 7500 feet, although, if stronger winds or more snow is received than expected the hazard could raise to Considerable at the high elevations. New wind slabs with depths to two feet could be found in steep loaded terrain. These slabs could be triggered by riders or skiers, particularly near cliff edges and on convex rollovers. Deep slabs, although slowly becoming more unlikely, could still fail. Initiation of one of the deep hard slabs is likely to take a large trigger such as a falling cornice, or a snowmachine impacting a weak spot on a slope.
