Nuking in the Swan

Investigated the site of the avalanche accident on Spring Slide Mountain on January 5, 2019.   Will update the accident observation tomorrow with details.  Today, we found dangerous avalanche conditions with numerous natural and human triggered storm slabs.

• 12" to 16" of new snow at mid and upper elevations.   Very heavy snowfall rates this afternoon, ~2"/hr.  Strong winds with intense snow transport at ridgetop.
• We observed a large (D2) storm slab run naturally this afternoon and saw the crown of a smaller storm slab from earlier in the day.  We also intentionally skier triggered several slabs up to 15" thick, D1 to D1.5.  
• We noted shooting cracks ranging from 1' to 10' long at mid and upper elevations.  Slabs that were stiffer from wind affect (both leeward and windward) were more reactive and produced larger cracks than in sheltered slopes.  We observed one large collapse with cracks radiating 50 feet on a shallow, windward aspect. 
• Pits showed easy, propagating results within the storm snow, 1' deep, and no results on deeper layers.  
• Given plenty of obvious signs of instability, we kept to mellow slope angles on our descent until about 5500'.  Below that elevation, slabs were generally too incohesive to be reactive, and we practiced sluff management in steep but small pitches.