Avalanche: Two Dogs

Matt B

Salt Lake » Big Cottonwood Canyon » Days Fork » Two Dogs

Two Dogs

10,200'

Northeast

Skier

Soft Slab

New Snow

16"

70'

Fist at surface down to 2F @ bed surface. Bed surface was a 1F hardness wind crust at the top of 4-6" of slabby snow from the first storm last week. Below that was the crust from the March heat wave. This setup produced a widespread cycle under skier load but thankfully manageable given depth and speed of release.

Partner triggered a slow roller in Days last Saturday. Trigger point appears to be the turn close to the rock wall atthe very beginning. This mimicked a slide about 150" east of this run, which also triggered in rocky terrain, likely on Friday. Both slides traveled most of the track, est 300' vert. The Friday slide had debris several feet deep while this one was about half the size, with less sympathetic propagation. My partner saw the slough up high, monitored it & moved aside when he saw the slab release at the stauchwall. Being an idiot focused on filming i was slow to recognize the scale of the slide and by the time I could radio a warning he was already out of danger. A good reminder of where the edge is & why minor terrain variations and incremental decisions matter in the mountains. While we largely gauged the risk and snow well, loved ones would likely request a bigger margin of safety. A couple adjustments like no partner and a little colder snowpack could have produced a very different outcome. I did ski West Bowl and Eemas on Thursday afternoon as the storm cleared, so I felt like I had a good read on the upper layers. On the Emma's I'd triggered a small but similar profile slide which seemed at the time like a density change soft slab. Upon inspecting the slide the partner triggered on Saturday it became apparent the weak layer was a wind crust formed sometime between loading events 3/30-4/2. The second storm didnt bond well to that crust and it seems as though NW battered some of the polar aspects, creating a surface layer firm enough to generate a bed surface. While atop Flagstaff there were 4 or 5 similar size, depth and trigger point slides in view.