Sunnyside of Hatch Peak

Our group of five traversed over to a sunnier aspect of Hatch Sunnyside for the last run of the day into Valley of Sin after skiing a shady north aspect. There were some ski tracks and skinner on the same slope from a group earlier in the day. I was the first to ski, and after only two or three turns the snow was feeling slightly unsupportable. I began seeing the slope fracturing in front of me, but by the time I realized what was happening it was too late. I was carried into a terrain trap to and rode the slide probably 1200 ft. While the slide was still in motion, after some chaotic shifting of the wet blocks of snow, I had an opportunity to release my splitboard bindings and was able to get on top of the snow mass, where I stayed until the slide came to a stop. No injuries were sustained and I was able to recover my splitboard after a few minutes. For me there still remains a lot to unpack, but right now I'm just happy to have walked away from the incident unscathed, and that I was with partners that were quick to respond. No signs of instability were observed throughout the day other than some point releases off of warming rocks.

FORECASTER COMMENTS:

We'd like to thank the party for sharing their experience. These first-hand reports are incredibly helpful for us all and offer valuable lessons in our own management of challenging problems and accidents. After chatting with the party and reviewing the information, our position is that the avalanche was likely a Persistent Slab. While strong warming played a roll in the slope's instability, good overnight re-freezes likely limited free water percolating to the weak layer. Instead, it's likely that the sun warmed and thickened the starting zone into more of a cohesive slab, contributing to its tensile strength and increasing its likelihood of triggering. Regardless, these are both challenging and dynamic problems that were not on the menu that day. Springtime avalanches have a habit of changing type as they descend the track and deform with friction, which happened in this case and led the avalanche to pick up more snow and present a debris flow that appeared and behaved much more like a wet avalanche. 

Kudos to the party for quick thinking and strong ability to maintain composure. Reports of this avalanche varied in destructive size from 1.5 to 2.5 and likely settle somewhere in between. It was most definitely capable of burying, injuring, or killing a rider, and the terrain trap compounded the debris into a constricted area and increased the avalanche's severity. We're grateful for the report and that no one was injured.  xo HPAC