Saturday, February 1, 2003

Six boys and a girl from a private school near Calgary were killed in a huge avalanche on Glacier National Park, British Columbia. They were on an annual school tour guided by school staff. The avalanche danger was rated "considerable." I find it difficult to understand why they were out in that place at this time. The Revelstoke disaster a few weeks ago, the "considerable" rating, the well-documented weak layers, a large group, would seem to suggest a "no go" decision. Especially with kids. Here's the opening of the relevant avalanche bulletin: Another 10cm of snow overnight is adding to the light, yet steady snowfalls that have accumulated since midweek.  The new snow has fallen under mild and at times windy conditions in a warm southwest flow.   Thus, a total of 30 cm load of storm snow is contributing to the stiffening of the slab over a surface hoar layer responsible for last weeks extensive avalanche cycle.  Snowprofile work done yesterday concentrated on West and North aspects both around the 2100 meter range.  Stability tests showed consistent failures on the Jan 20 surface hoar with scores in the moderate to hard range.   The new snow instability described yesterday, now over 30 cm deep, was also observed on the west aspect.   Given the recent and past wind events, these are the layers of highest concern at this time, especially on lee slopes or near large terrain features.  Ski tests easily released the Jan 20th layer on unsupported rolls on the north aspect. Notice that last sentence. They were on a North face. 10:49:11 PM