Wind slab NW Andesite

Touring up the back side of Andesite, from the north, near the top of ridge we found 15cms of one finger wind slab (12/17,18). It was cleanly failing to ski cuts on a mix of fist hard grauple, decomposing fragments, and small surface facets.  This wind slab was isolated and reactive to ski cuts and moving tests. Propagation was limited to meter sized blocks.  Also down in the sheltered areas open to the sky was well developed surface hoar. See photos