Turnagain Pass

On Monday we got a report of a disconcertingly large skier triggered avalanche in the Girdwood valley.  It appears to have been remotely triggered near the 2700 foot elevation and slid on or under a 2 week old crust which is now buried 2-3 feet deep.  Yesterday we confirmed the reactive nature of that weak layer.  See the full test results on our observations page.  Our testing found a specific elevation band between 2000 and 3000 feet contains a series of crusts and facets that can collapse under the weight of a person and propagates large distances.  Snow pit testing shows only moderate strength, and failure happens in a clean and fast nature. 

We don’t know how widespread this problem is.  It appears to be common in the Girdwood valley, but so far we have few reports across Turnagain Pass that correlate to a reactive ice crust.  However, it should be assumed to be common at the mid-elevation band regionwide until we prove otherwise.  This problem is not likely to go away quickly, and may get worse before it gets better. 

Wind slabs, large cornices, and building storm snow will be a problem above treeline.  Over the last week, no single day has brought a large amount of snow, but the combined 7 days equals close to 20 inches of new snow at Turnagain Pass and perhaps double that amount in Girdwood.  Wind has been consistently strong.  We can expect to find areas of stiffer and deeper wind deposited snow which may be triggerable by a person.  Any steep wind loaded terrain above treeline should be approached with caution corresponding to the terrain consequences.