If the same avalanche had occurred on a slope shaped like an alluvial fan, the victim most likely would have been caught in snow that was less that knee deep, and probably could have easily stood up and walked away. However, a month or so prior to this period, the temperatures had been in the single digits and teens. During this period, the shallow snowpack became faceted at the ground. The snowfall of the previous day was without wind until the last couple of hours, when gusty 25-30 mph winds resulted in shallow soft slab formation in leeward pockets. Moderate winds near the end of the storm created both low density wind slab and additional load.
Intermediate facets are notoriously weak in shear, but surprisingly strong in compression.
The added load of the new snow, the weight and dynamic energy of two hikers, and the incline of the slope all contributed to an increase in stress. The facets were simply not strong enough to hold the slab in place. The avalanche hazard was moderate at the time of the accident. No evidence of recent avalanche activity could be seen along the route. No collapsing of weak layers or shooting cracks were observed.