Size 3+ skier-triggered avalanche at Rogers Pass

ACMG Mountain Conditions Report

Thursday, December 1, 2011

[MCR] Rogers Pass avalanche

A skier triggered size 3+ avalanche occurred late this afternoon on Grizzly Gully, off the summit of Grizzly Peak.  The first skier of five did a ski cut in the start zone with no result.  The second skier in made another ski cut, again with no result.  Upon doing a kick turn in a shallow area however, the slope in the start zone failed down 1.5-2 meters, producing a large avalanche that ran to 1700 meters (the pinch-point of the Grizzly path).  It ran 800 vertical meters, over about a kilometre.  The snow lower in the path was primarily storm snow, down about 50cm.   One skier was involved, sustaining serious injuries, and a second lost some equipment.

Although conditions seem to have stabilized in Rogers Pass, with few new natural avalanches running over the past few days, some instabilities still linger near the base of the snowpack.  It is unknown whether this was related to a buried surface hoar layer from earlier in the year, or whether it was wind loading of the large amount of storm snow from last week.

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