Stiff wind slabs on Lincoln Ridge.

Only a minor dusting of new snow greeted us when we arrived at Yuba Pass this morning. Up on Lincoln Ridge, signs of drifted snow last night became apparent on the approach with filled in tracks below the ridgetop and new cornice formations. Approaching the edge of a newly formed but rather stiff wind slab gave some minor cracking. Dropping mini fridge size cornice sections onto the main portion of the wind slab did not produce any additional wind slab failure.

While approaching the ridgetop we stopped to dig a snowpit in an open area below treeline that was just out of the wind affected area. The Dec 11 PWL appeared dormant in this pit location, but PST test results and CT sudden collapse results indicated the potential for reactivation of this weak layer with future loading.

We had just a single whumpf (audible collapse) while touring in this area today. This whumpf occurred along the ridgetop in near treeline terrain where a wind pillow had been drifted onto a NE aspect slope that held the Dec 11 PWL. Skiing over the top of this pillow produced the collapse.