Northern San Juan

After skiing part way down low angle ridge, skiers decided to ski a short pitch of steeper terrain into basin. 1st skier dropped and skied majority of run, then avalanche was triggered at edge of ridgeline when 2nd skier stepped towards cornice to watch 1st skier exit run. Avalanche started at cornice, creating a crown that is over 4 ft deep in places, and propagated nearly 1000' wide. Avalanche ran for 500' to basin. 2nd skier was briefly caught as cornice broke beneath him but was able to scramble off of moving snow onto bed surface just below the ridgeline. Debris was quite deep and the speed of slide was surprising. Width of propagation and size of avalanche was also quite surprising. No one was buried or injured.

Warm weather, light to moderate winds.

Dense wind ripple snow on run that slid. Persistent weak layer problem has existed since last storm cycle and other small natural slides were observed on similar aspects and elevations during tour.