Submitted by Avalanche Canada
Avalanche Canada, in partnership with Parks Canada, Kananaskis Country, and the province of British Columbia, is issuing a Special Public Avalanche Warning (SPAW) for recreational backcountry users across the mountainous regions of western Canada. A dramatic increase in temperatures is expected to destabilize the snowpack, resulting in dangerous, destructive avalanches. This special warning is in effect immediately and will apply through the end of Monday, May 1. For a map of the SPAW region, click here.
The sudden transition from cool, wintry conditions in the alpine to warm temperatures will create dangerous avalanche conditions. The effect of the warm temperatures on the existing snowpack structure means that these avalanches will likely be very large and may run to valley bottoms.
Dangerous avalanche conditions exist for all mountainous regions in western Canada and the hazard increases with each day of warm air. Regions with persistent or deep persistent slab avalanche problems will be especially problematic, with avalanches potentially involving the full depth of the snowpack.
Warming can also initiate large and destructive cornice falls. Cornices can be destructive by themselves but also act as a trigger for destructive deep persistent avalanches.
All backcountry users, including hikers and scramblers, and anyone recreating in avalanche terrain are advised to leave a wide margin for error during this warming period, stick to simple, low angle terrain, and avoid all overhead avalanche hazards.
Backcountry users should always check the avalanche forecast at www.avalanche.ca. Everyone in a backcountry party needs the essential rescue gear—transceiver, probe, and shovel—and the training to use it.