Skied Big Mac in Canyons backcountry. I triggered a 10-12" deep pocket in a wind loaded starting zone. Soft slab possibly broke on density change (wind loading or graupel likely) ran mostly full track (600') down gully on skier's right of track. The slide released a deeper pocket possibly 18" deep skier's left likely on pooled grapuel below steep rocky feature, which ran roughly 200' on the left side of skier's tracks before piling up on gully terrain feature. Ski tracks weren't overrun as they were on lower angle terrain/subtle ridge around which the slides split. I didn't realize slides had released until I was stopped in a safe zone and saw powder cloud and debris coming to a stop. Didn't see many other signs of instability though there were occasionally high precip rates and enough wind for significant transport. Fortunate to have found the instability on a less exposed slope. Snow was 5 stars so we backed off the slope angles and enojyed the rest of the day.