Avalanche out of bounds at Norquay

Natural avalanche seen above Mystic lift at Norquay whilst out skinning. Size 2. Dry slab, crown was at about 2300m, east aspect. 1m deep crown, 30m wide and ran around 150m. Rough estimates as I was far away, but the crown was very visible. No tracks were visible around area, rock and snowfall from rocks above is common so could have been a trigger.