Avalanche: Turnagain

Reaching tree line during our approach, we noted roughly 10 skiers ascending Cornbiscuit and multiple wide, interconnected, deep crowns from natural avalanches in a variety of aspects and elevations in the Superbowl area, Cornbiscuit north facing couloirs, on Seattle Ridge, and later on Sunburst S Face. My partner commented on the fact that the north facing Cornbiscuit slopes closest to us hadn't slid. After leaving the Cornbiscuit approach, partner and I traversed across the drainage between Cornbiscuit and Magnum and began to ascend on an established skintrack. We followed both skin tracks and descent tracks on the traverse. We had climbed approx. 400 ft into PMS bowl when I heard what I assumed was a 737 on final approach before turning around to see the large slope above where we had traversed avalanching, covering a large portion of our tracks through the drainage and running approx. 1000 ft. A burial would have been very deep given the terrain feature. We are both glad to have been lucky and ski another day.

Some takeaways:
Avalanches can be remotely triggered while climbing and descending. We were off guard because we doubted anyone would drop to descend the slope we were traversing under.

We didn't give ourselves enough space on the traverse due to above.

Intuition is a good thing. I've seen slides in this area and my partner was questioning the slope as well. Acting on either of these thoughts would have meant taking a safer approach to our objective.

From reading the accounts from others on Cornbiscuit, this avalanche, along with a large slab on the south face of Cornbiscuit, was most likely triggered by people on the ridge, or the group that was skiing on the S face of Cornbiscuit.