Dense surface slabs lie upon persistent weak layers comprised of buried surface hoar. These slabs have gained volume and could be triggered on approach, after being crossed multiple times and on lower angle terrain than one might expect. Two days ago a guide was caught, carried and fully buried in the Snake River Range. He was uncovered by companion guides and was not injured. The potential for humans to unintentional trigger dense slab avalanches with severe consequences is significant.
At the mid and upper elevations dense surface slabs up to two feet in depth could be human triggered on buried layers of surface hoar in steep terrain. In isolated areas some potential may exist for these slabs to step down to deeper layers of buried surface hoar with depths to three feet.
A high pressure ridge will build into the region from the west. Limited moisture in a northwest flow ahead of the ridge will keep a chance for snow showers in the mountains overnight. Clearing skies are expected on Tuesday. Northwest winds will slowly relax from speeds of around 20 to 10 miles per hour as the day progresses. Temperatures will drop to around 10 degrees by morning and rise into the teens and 20s during the day.Dense slab avalanches with depths of one to three feet could be human triggered in steep terrain at the mid and upper elevations. Shallow dense slabs up to foot in depth could be human triggered at the lower elevations in areas that do not have stout rain crusts. These slabs lie upon a persistent weak layer and will remain problematic with respect to the potential for them to be unintentionally triggered. The general avalanche hazard is expected to be MODERATE above an elevation of 7,500 feet and LOW below that elevation.
