co-pilot storm and wind slabs

Scary day -- skier-trigged size 2 on a N/NE 40 degree slope just below co-pilot peak. One skier was caught and knocked down but was able to regain footing and ride across the slope to safety. Previous group of ~10 rode the gulley with no problems; just reaffirms that you can't assume a slope or drainange is safe because someone else rode it without problems or because the avcan rating is only moderate. Significant wind-loading was apparent once dropping into the slope and so the skier immediately started cutting across to safety but was still caught when the slope slide on the ~3rd turn. Skier trigged a ~40 cm crown which propogated across the slope. In some areas that stepped-down from the wind slab to storm slab of similar size. You can see in the last photo some shooting cracks along the wind slab which stepped down. Wind loading was extremely variable and unpredicatable; we actually cut our objective short and tried to get out faster. Snow was amazing, of course, but very reactive. Felt a lot more like an interior snow pack than a coastal snow pack. We were expecting more consolidation but with the cold temps and wind the snow was a lot more reactive than expected. On reflection, we should have stayed out of the alpine where the winds were more aggressive. Treeline conditions were just as good and less reactive due to lack of wind loading. With last night's storm-slab now on top of these layers I expect significant risk in this area until these layers consolidate.

N/NE aspect. Did not slide in same gully at lower angle. Same slope angle 100m down-elevation at lower angle (~25 degrees) did not slide either

Triggered by skier who was knocked down but able to gain their footing and ski out. Mutliple triggers on the same face as the crown propogated. Other group members were in safe locations with eyes on the skier the whole time. Fortunately nobody was injured, and ideally this incident would not have happened, but proper preparation and group-planning ensured the incident did not result in injury or wose