Slow moving avalanche

Went up to Wheeler Ridge a few miles away from Bear Valley, at about 8600ft. It's a flat ridge, wind scoured and on top of a North Western slope with a few cliffs. Strong winds, as it was forecasted and I saw snow being swirled around so I was careful as I expected wind loading. I never skied that slope, but I would guess it is about 30-35 degrees. I stayed at least 20 feet away from the cliffs because I suspected cornices. I wanted to see whether I could ski down that slope but when I traversed on top of the cliffs and finally had visibility of what was going on below, I saw the slide happening. Nothing too major, not moving very fast, but from above the debris field looked fairly substantial. I left the area at this point and didn't want to take any more chances, so couldn't see from below. I'm not sure how this happened. I was at least 150 feet away from the slide, and probably 150 feet higher. I didn't see a cornice collapse which could have triggered it. Possibly just the stress of me standing above the cliffs somehow triggered it.