Avalanche: Summit

Started to skin across the north side. Not positive of the exact altitude but there were still trees around me. I was going to check it out to see if it was worth coming over to or if we should just ski the ridge down.
I got to a point about 200 yards from the where I crossed the ridge, heading southeast, and realized it was a waste of time. I was about to turn around and there was a giant whumph under my feet and I looked behind me and the slope was sliding above and behind me, but didn't slide where i was. One in the group slid for about 30 feet but not buried. Not exactly sure how wide the slide was but I would say about 100 yards or larger and it ran down into the trees so you couldn't tell how far it went. I estimated the slope to be between 30-32 degrees from past experience and others input. The crown varied due to snow drifts around trees but id say an average of 18 inches to 2 feet. It was a hard wind slab. It didn't give any red flags, no shooting cracks and no whumphing until the actual event. I didn't do any more investigating or take good pictures because we were working on getting off the slope.