A few observations from the Duffey Lake area in a drainage immediatley south of Cayoosh Mountain:
The skies opened today and it was a pleasant day to be in the high places while turning the legs over.
The snow turned moist quickly once the sun began heating things up. Dry snow is still accessible on true north-facing terrain with good powder that's 20-25cm deep. At open below treeline locations on north aspects, this powder snow is sitting on a crust located 25-30cm below the surface. Tests showed a clean, 'sudden' result where this recent storm snow rests on the crust. Fortunately, the snow at these particular below treeline locations was still quite soft so the hazard is a little lower. As you climb to treeline, and just above, the snow (and hazard) changes.
A party of recreational tourers skier-triggered a healthy size 2 slab avalanche (large enough to bury a person) today on an east (with a little north-facing bias) aspect at an elevation where the treeline thins and the alpine begins. I strongly suspect that this slab ran on a crust. The interesting thing about the terrain, from which the slab was triggered, was that the avalanche began much lower in the start zone on a large convex feature. Essentially, the very strong winds that we recently had relocated much of that snow lower into avalanche start zone locations than usual. As such, it seems that it may be possible to trigger an avalanche from lower down. The slide ran from an adjacent steep cross-loaded slope into a gully-like feature that they were attempting to ski. It was triggered where the gully met the cross-loaded slope.
Cornices continue to be a significant overhead hazard and so, too, are large sun-baked slopes.
On the drive home to Whistler, the clouds were thickening to the west and wind speeds in the mountains had begun to increase. The next system approaches!
'So foul a sky clears not without a storm.'
~ 'Yep', Shakespeare....
Hoping this finds Everyone keeping well and enjoying the Spring touring season....
Best regards,
Dale Marcoux
ACMG Asst. Ski Guide
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