Numerous avalanches were visible on the west facing terrain of the Giant Stair Case from the backside of the UFO Bowls (pic below) up to the northwest face of Roberts Horn. If you look close you can make out crowns in some of the chutes.
Not visible in this photo but most of these chutes avalanched during the storm.
Numerous crowns are visible on the northwest face of Roberts Horn. These paths are all 800 to 1000 feet vertical.