Avalanche: Butler Basin

My party observed this from Wilson Peak. Party of two skinned up Butler basin, gained the ridge, and each took a lap off the ridgeline....just above what is sometimes called the Triangle. The party skinned back up to take a second lap. The first skier dropped in 50' west of the previous tracks and appeared to trigger the avalanche immediately..and was able to outrun the avalanche. No tracks exited out the skier's right...the slide just engulfed his tracks. It's possible that the slide was triggered remotely well below the fracture line...but where the tracks "enter" the fracture line the slab was 1'/30cm thick; elsewhere the slab was 2' deep.

Weakness in question is from the 2/9 storm that began with graupel and followed with roughly three more inches of snow. The snow above the graupel faceted under clear skies over the next 11 days until it was buried on the 20th with 6-10" of snow. This wasn't enough to activate the layer until this past few days of storms which brought 2-3' of snow since 2/26.

1- pointing out this interface on 2/22 from field report Kessler/Mineral

2- interesting conjecture - the ski tracks defined the skier's right flank of the slide

3- Slide left up to 10' of debris

4- looking up and across the crown

5- touring partner Nat Grainger (Snowbird ski patrol) investigating the weak layer

6&7- 1mm faceted grains - the weak layer that has prompted collapsing, remotely triggered slides and many slides triggered on 3/3 and 3/4.