Blowing snow and signs of wind slab instability on Andesite Peak.

Driving up to Donner Summit mid morning blowing snow was apparent on all ridgetop peaks along the Sierra Crest, giving us a good idea of what to expect in terms of wind slabs. As we transitioned from wind protected below treeline to wind exposed near treeline terrain we started to see moderate amounts of blowing snow. As we continue up above treeline, old skin tracks were filled in by drifting snow and wind slabs up to one foot deep became apparent. Stepping on some of the most heavily wind loaded test slopes produced shooting cracks up to 20 ft long and 1 ft deep. Signs of instability were variable in spatial distribution with significant shooting cracks in some areas of newly formed wind slab and no cracking in others.