CORNICE COLLAPSE, AVALANCHE
British Columbia, Yoho National Park, Mount Vice President
On April 9, an American man who was backcountry skiing in Yoho National Park died when he was swept away by an avalanche. Park wardens discovered the man’s body at about 1800, buried under about 60 centimetres of snow. He had been skiing on the Vice President, a popular destination for backcountry skiing and mountaineering in the Little Yoho Valley. The victim was standing apart from his party on top of a comice when it broke off. The human-triggered comice failure produced a size three avalanche on an east aspect starting at 3100 metres and running full path. The slab stepped down to the rocks with the crown over a metre deep in some places. The victim was carried more than 600 metres down the mountain. The party, comprised of five or six members from both the U.S.A. and Canada, had a satellite phone and was able to call for help. Six wardens and two rescue dogs were called to the scene. A helicopter with an avalanche beacon suspended below it was used to locate the victim.
At the time of the accident, the avalanche forecast was low but contained specific reference to increasing instability resulting from daytime warming. The forecast warned skiers that large cornices are starting to fall apart. This cornice failure occurred in the afternoon. The same day, a number of other natural avalanches were observed on sun-exposed slopes, demonstrating the deterioration of the snow pack that occurs in the afternoons with spring weather. In the spring, skiers are well advised to get up very early to enjoy the best conditions and finish their ski day early before afternoon warming creates isothermal conditions. (Source: Genevieve Svatek, Banff Crag and Canyon)