I unintentionally triggered an 18" deep, 250' long, 20' wide avalanche while skiing "Miny" in Mill B South. I entered a small, short chute-like feature from the top and as I made a turn after entering, something felt a little off as though my skis were really sinking into the snow. I picked up speed, made a few more turns, and cut out to the side. I turned around a watched my sluff move slowly past my position. It was then overtaken by a quick moving D1 avalanche.

As I was coming into this terrain feature, I was well aware of issues with sluffing that I had been expecting and experiencing. I knew that I had to move quick and get out of the way as I got out of this feature. When I was skiing, something felt off and I got up speed and got to my safe area. It appears that this avalanche stepped down to the buried facet-crust interface in the terrain feature (20'x20' area) but below that ran on top of the crust. I think this was triggered by my ski breaking into the crust, down to the facets and not the sluff stepping down.

8500', E aspect, ~40 degrees, skier, unintentionally triggered, 18" deep, 250' long, 20' wide, D1/R1, buried weak layer