The Canadian Avalanche Centre has issued a special avalanche bulletin for most of British Columbia, including the North and South Columbia mountains around Revelstoke for this weekend.
“The clear, dry spell covering the province in early February had a weakening effect on the surface of the snow at that time,” said Karl Klassen, manager of the CAC’s Public Avalanche Warning Services. “Now that surface is buried and left us with a very complex upper snowpack, with a number of weak layers. Conditions are very tricky to manage right now. If you’re going into avalanche terrain, you need local knowledge, extensive experience and training.”
The CAC has rated the avalanche danger as high in both the alpine and at treeline; and considered below treeline for the North and South Columbia’s on Thursday and Friday. The danger ratings drop to considerable at all elevations in both regions for Saturday.
The CAC is advising all recreational backcountry users to monitor avalanche bulletins and make sure they’re well prepared with a shovel, probe and transceiver when heading out into the backcountry. It is also recommending people take an avalanche safety course.
A posting to the CAC’s Forecasters Blog on Wednesday afternoon highlights some of the concerns with the snowpack. It states:
“We are receiving reports that experienced backcountry travellers are pulling the plug early today and coming home due to avalanche concerns. Some folks are saying they are remote triggering 20 degree slopes from 70m away on surface hoar. Large natural avalanches (to size 3.5) are running in the alpine where windslabs have formed.
In the Purcells, Selkirks, and Monashees at least and maybe other places it looks like all those slopes that have been hanging on by their fingernails are letting go and it’s going off out there.
It’ll take time for this to settle down and residual problems will likely persist well after the initial period of very poor stability and obvious avalanche danger is over. This may be just the beginning, so heads up for the next week or so.”