Fragile Cornices and Wind Loading on Castle Peak

About 10 inches of new snow greeted us upon our arrival at the Castle Peak trailhead. On our way up to Castle Pass, we hopped out of the track a few times to test some small but steep test slopes right next to the trail. In these sheltered areas, the new snow felt right side up (less dense snow on top with more dense snow near the old snow / new snow interface). The snow near the old snow surfaces was also still wet. Ski cuts on these test slopes did not trigger any cracking or other signs of storm slab instability. Hand pits also revealed decent bonding between the wet snow and the new snow above it. 

As we continued onto the west ridge of Castle Peak we started to encounter signs of wind-loading. There were several cornices and small wind-loaded test slopes. The small cornices would break easily when we kicked near them with our skis but the pieces fell onto the wind-loaded slopes below them they did not trigger wind slabs. They did entrain some of the snow in a sluff (loose sliding snow). Father up the ridge the cornices above the test slopes got larger and even more tender. Ski kicks well away from the edges would release refrigerator-sized pieces of cornice. On one of the most heavily wind-loaded test slopes, one of these large cornice pieces did cause some cracking and a small wind slab failure in the slope below. The wind and wind-loading continued to increase with elevation. Near the summit, we wanted to look over into the N bowl of Castle but blowing snow and low clouds made visibility so poor that we could not see anything. We also did not want to get anywhere near the edges of the larger cornices in that area.

On the way down, we moved back into more sheltered terrain to avoid the large wind-sculpted features in more exposed terrain. As we descended below 8000 ft on the E side of Andesite Peak, we noticed that the new snow felt heavier and wetter than it had when we started up the trail earlier in the day.