ECTP's and Wind Transport on Castle Peak

Density changes still existed in the storm snow and were evident in hand pits and snowpit tests. One of these changes in density existed about 6 inches below the surface of the storm snow and one of them existed near the base of the storm snow. Snowpit tests in sheltered areas below treeline yielded variable results on these density changes and some tests showed unstable results and others did not (2 x ECTN, 1 ECTP on the density change near the base of the storm snow). Other observations like settlement cracks and ski cuts on test slopes indicated that the storm snow is gaining some strength in the sheltered below treeline areas.

In near and above treeline areas wind affected snow surfaces were widespread and wind loading had turned the 2 ft of storm snow into 5-6 ft wind slabs in the most heavily wind loaded areas. Some weaknesses existed in the wind loaded snow and snowpit tests did yield unstable results on a density change about 12 to 18 inches from the snow surface (ECTP). Active wind loading was ongoing on the near and above treeline slopes. An oven sized cornice piece dropped onto a previously wind loaded test slope did cause some cracking on wind loaded ESE facing slope. Another oven sized cornice piece dropped onto a wind loaded slope on Andesite Peak did trigger a wind slab avalanche (click here for more information).

Photo 1: Wind loading across a ridgeline on Castle Peak

Photo 2: Settlement cracks near a tree on a below treeline slope