Avalanche — East Slopes Northern Cascades, Washington

2011-03-05 · East Slopes Northern Cascades, Washington

Event narrative

A 28 year old male skier triggered an avalanche at the top of Hooky Bowl located near Mt. Cashmere. The slab depth, at the point where the avalanche was triggered, was just over a half a foot in depth and increased in depth up to three and one quarter foot. The horizontal dimension of the slab was approximately 3 feet by 200 feet. The skier was carried through several groups of trees and funneled down a steep gully. After the avalanche ended, the skier was found alive with one leg dismembered and the other leg suffering significant fractures. Other skiers arrived within two minutes of the event and performed lifesaving measures immediately, however, patient eventually died as a result of his injuries.

Wider weather episode

A substantial rain event in mid January resulted in a strong, thick rain crust on an already established snow pack in the east slopes of the Cascades. Mid-January to mid-February was mild with only modest amounts of snowfall added to the slopes. Temperatures were much colder through the end of February and a series of storms from February 28th through March 4th resulted in heavy snowfall over the thick icy crust. This series of events resulted in an unstable slab of snow susceptible to avalanche formation.

Source: NOAA Storm Events Database, event_id 285786. Narrative written by the NWS forecast office that issued the report.