Front Range
AvalancheMauri Dimeo · Dec 26, 2016 · Front Range
Weather
Geneva Basin, SE aspect, 11,000ft. Clear and very windy, some gusts strong enough to knock a person over.
Snowpack
Geneva Basin, SE aspect, 11,000ft. Wind slab over depth hoar. The entire SE face of the bowls slid since I was there 48hours ago. A snowpit (Dug on 12/24/16) picture is shown below. The Very Large avalanche initially failed at a weak layer above the ground, but did step to the ground a short distance below the crown.
Avalanche
The slab that slid went big, R5 and at least D3 and down to the ground. It looks like there were smaller slides on wind loaded slopes that triggered the persistent weak layer at convex rolls. Crown for the persistent layer was about a half mile wide and was over a meter thick at the thickest. The slab propagated around terrain features and even slid on lower angle slopes of about 30degrees. There was a smaller slide to the north that had a deep crown but did not propagate beyond the slope.