Sluffs, Wind Slabs, and Cracking on Hidden Peak

Hand pits, ski cuts, and snowpit tests indicated the new snow was not bonding well to the frozen crust at the base of the new snow. In most areas the new snow remained un-cohesive and had very few slab characteristics. In these areas it would sluff away from the crusts with a push from a ski. In open areas where it was slightly wind affected in below treeline terrain the new snow had enough slab-like properties for some skier triggered cracking to occur on convex rolls. On one wind affected, NE facing, 40 degree test slope a ski cut triggered a 12-14 inch soft slab failure with the new snow sliding on the frozen crust.

In more exposed near and above treeline terrain near the summit of Hidden Peak, active wind loading was occurring and wind slabs were present on wind loaded slopes. In some areas wind loaded snow depth measured 3+ ft. Ski cuts on steep wind loaded tests slopes produced shooting cracks and one small wind slab failure. 

Snowpit data showed a snowpack that measured over 6 ft in depth at 8500 ft. and did not reveal any signs of instability around the Dec. 13 rain crust or the surface hoar that once existed beneath it. These layers have become very difficult to even locate in the pit. Snowpit tests also did not reveal any signs of instabilities. ECTN 4 within the new snow, ECTN 14 at the new/old interface, ECTN 22 just below the most recent rain crust (12/24 rain crust), PST 125/125 just below the 12/13 rain crust where the surface hoar used to be.

Parties also reported some skier triggered sluffing and cracking on Jakes Peak and some skier triggered cracking on wind affected slopes near the summit of Rubicon Peak 

Photo 1: Small wind slab triggered by a ski cut on this test slope in near treeline terrain on a NE facing slope at 9000 ft. 

Photo 2: Skier triggered shooting crack on a wind loaded test slope. 

Photo 3: Soft slab on a 40 degree, NE facing, open, wind affected test slope located at the GPS coordinates attached to this observation.