Small wind slabs near Castle Peak

In our AIARE1 class today, we toured up to Castle Pass and up the West Ridge of Castle Peak to about 8300’, before skiing the N/NW-facing terrain down to Round Valley. We experienced moderate snowfall all day, with moderate to strong winds out of the south. 

Along the ridge above Castle Pass, some cracking when stepping above the skin track (photo 1) indicated small pockets of wind slab formation, ranging from 4” to 8” deep, on the north side of the ridge. 

After dropping down a short distance from the ridgeline for better teaching, we dug a pit (photo 2) at the dropped pin location to examine the now buried facet layer. At that point, around 12:30, there was about 5” of soft new snow on the 12/11 rain crust, with F-hard facets beneath that. While demonstrating a compression test, the upper portion of the facet layer fractured while cutting through the rain crust (CTV SP down 18cm). 

When we left Round Valley around 2pm, roughly 5-6” of new snow had fallen and the snow seemed to be getting warmer and wetter.