Unstable wind slabs on upper Hidden Peak.

Signs of significant wind slab instability observed above 8,800' on Hidden peak this morning. Below 7,100' snow cover was very thin from recent melt and rain events. Wind effect became more prominent around 8,200'. Shooting cracks became widespread above 8,800'. Gale force SW winds were transporting large amounts of snow in the upper 300' to 400' vertical feet of the peak. Shooting cracks up to 3 m long were observed, but the rate of drifting and refill was so fast that they were barely visible by the time I could get the camera out of my pocket. Hence no good photos of shooting cracks.

Signs of a natural wind slab avalanche, likely from early this morning were observed along the summit ridge at the noted lat/long. A mostly refilled 1 foot crown was present along with en echelon cracking of the snow surface in an area approx 100' wide x 50' downslope. Poor visibility lead to no usable photos.

Rain soaked wet snow, drained but not refrozen was noted below last night's storm snow up to an elevation of 8,700'. New snow amounts above the rain wetted layer ranged from 10 cm at 6,600' up to 40 to 50 cm above 8,000'.

No signs of unstable storm slabs were observed in the wind protected areas below 8,000'.

Photo 1: Thin snowcover near the base of Hidden and Hwy 89 at approx 6,700'.

Photo 2: Skin track refill after about 3 minutes in near treeline terrain at around 8,800'.

Photo 3: Blowing snow on the summit ridge. Observed signs of natural avalanche were located just below the ridgeline in the relatively open area near the center of the photo.

Photo 4: Wind slab cracking in near treeline terrain around 8,850'