6996

We took a closer look at a previously reported large avalanche in southern Glacier Park's most popular spot for backcountry skiing. 

• The avalanche started just a few feet below the summit at 6990 feet and traveled to 5700 feet. This is about 2/3-3/4 of the path.
• A soft slab of wind-blown snow triggered a larger hard-slab avalanche on weak faceted snow 90 cm beneath the surface. 
• The slide was confined to the skier's left side of the east-facing avalanche path, locally known as the Big Run. Partway down, the slide propagated right but still left most of the skier's right side untouched. The left-hand side is steeper and more open, with a convex terrain feature. 
• Recent winds had transported substantial snow and filled the crown in most locations.
• The slide ran on top of a stout crust for most of its length. It broke through this crust near its terminus.

Moist unsupportable surface snow below 5800 feet. Supportable with dense new snow above that.