Vail & Summit County

Avalanche

Andrew McWilliams · Nov 18, 2022 · Vail & Summit County

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Observation photo 1Observation photo 2Observation photo 3

Weather

Sky was overcast with S-1 snowfall for most of the morning. There was a brief period of S1 snowfall but there was no significant accumulation. The sun was beginning to break through the clouds as I was leaving.

Snowpack

Overall this area still has thin coverage. Recent winds have built a stiff slab beneath the new snow which overlies the decomposing slab from November and then facets on the ground. Snow depth varied from 60 cm to 10cm. Just beneath the ridge was a pillow of wind-drifted snow. However it extended less than 10 feet from ridgetop. Grass, stumps, and rocks were still visible in many places poking above the snow.

Avalanche

The avalanche was triggered from the top as the party was skinning up towards the trees and broke at their skis. There was cracking all along the pillow up to the trigger point. Note the grass sticking up in the background indicating the overall thin conditions and isolated nature of wind-drifted pillows.