Blowing snow and stubborn wind slabs on Silver Peak.

On the approach to Silver Peak, we noticed blowing snow along the ridgetops in near treeline and above treeline terrain. This confirmed our expectation to encounter wind slabs. We identified the features of concern and carefully ascended up to the E Ridge avoiding overhead hazard from wind slabs and avoiding getting too close to the slab edges. Test slopes in the area revealed firm wind slabs that did not fail from kicks or ski cuts. This sent us to the snowpit to look for evidence of instability as informal observations were not providing a complete picture.

In the testpit at 8,000' on N aspect, wind loaded terrain at treeline (noted lat/long), ECTP results in the 22 to 25 tap range were very repeatable.  ECTP failure was occurring 1.5 feet down where 1F hard wind slab sat on top of 4F hard older snow below. These results gave us a more clear picture of difficult to trigger (stubborn) wind slabs with size D2 avalanches as the expected size.

With a good assessment of conditions, we found a spot to exit the ridge across 29-30 degree wind slab and moved into treed, wind protected avalanche terrain for the descent in good quality snow without the wind slab problem.