Persistent slabs do indeed persist.

Today we rode up into the Swan Range to sus out recent wind loading and get a sense for the sensitivity of the persistent slab problem. One measly cornice fall told us all we needed to know. 

• We noted numerous small natural avalanches that likely failed within the past few days from wind loading. These were mostly located on east and northeast aspects.
• Recent winds appeared to have transported snow on all aspects at upper elevation. The most recent wind slabs were on south aspects.
• We took advantage of a small to medium size cornice as a test for buried surface hoar. This cornice fell and triggered a large avalanche below. See photos and video for details. 
• We had no results in a pit test on a southeast facing slope at roughly 6700 feet. We did find faceted grains above the 1/13 crust in this location. We felt far more confident with southerly aspects, but still kept slope angles below 35 degrees for the day.

We found excellent riding conditions in mellow terrain on a southeast aspect.