[MCR] Portal Creek Drainage Jasper National Park

In anticipation of the delayed access restriction ending after today, we travelled into the Portal Creek drainage off of Marmot Peak to inform tomorrow's avalanche forecast. We saw evidence of several large slab avalanches to size 3.5 that had run full path, - likely 48 hours ago during the last warm storm. One crown on a NE slope immediately below the west ridge of Chak peak was at least 3m high and these large avalanches are scrubbing down to ground. Our test profile at 2350m on a SE sheltered slope had sudden collapses that easily propagated in the upper facets below the January 30th storm layer. At this elevation, the Jan 30th layer is a stiff 5cm thick band down 50cm from the surface - well within the depth of influence of a backcountry traveller. Weak facets/depth hoar below this layer extend from 75cm to ground.  

 

Despite the disappointing base of the snowpack, the upper well-settled layers of the last two weeks of warm storms carried our "delicate" skiing style well down below treeline on shaded aspects. A sandwich of several surface crusts on solar aspects makes travel a bit more challenging when you leave shaded terrain.

 

Landon Shepherd ASG

Steve Blagbrough MG

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