Quick report
We knew there was a risk of wind slabs in the N chutes area given the prevalent wind of the previous days. However, overnight the wind had changed to fairly strong NE winds, scouring that area. So going up it was unclear what instabilities we would find, but we were on the lookout for wind slabs near the ridge lines and dry loose on steep terrain as the main instability problems. Going up, we noticed strong NE winds depositing snow on the lee side and forming more cohesive, slabby snow. Anywhere sheltered from that wind and the previous day's winds had cold, unconsolidated powder. We did not observe any natural avalanches. We first skied a line on the S face (not avalanche terrain) and did not observe any signs of instability. We observed very heavily wind-sculpted and wind-scoured features on the top half of the N chutes. I almost decided not to ski them because it didn't look good at all. However, the bottom half looked nice and not wind-affected so we decided to drop. After the small avalanche (see avalanche report) we did ski a more mellow ENE facing line lookers right of the avalanche area. That area had light, unconsolidated snow that was not wind affected at all and skied wonderfully. A group of snowboarders in the area mentioned they kicked off a few small wind slabs halfway down the chutes that morning. I noticed they were riding fairly aggressive lines and thought I would be able to avoid the touchy areas. The top area looked wind-scoured and wind-sculpted by the NE winds. Traversing through the wind-sculpted top section, I got caught and carried by a small D2 avalanche, see avalanche report below.
Weather
- Air Temp
- 23
- Cloud Cover
- few
- Wind Loading
- moderate
- Recent Snowfall
- 40
Cold clear morning, with fairly strong NE winds on the ridges.
Avalanche
- Size
- D1.5 R2
- Type
- SS
- Aspect
- N
- Trigger
- AS
- Elevation
- 8500 ft
I triggered a small D2 avalanche while traversing through wind-scoured and wind-sculpted snow on the upper end of the Castle Peak N chutes. I was caught and carried for about 100-200 ft and deployed my airbag. Fortunately I was not carried al the way down. The avalanche continued to run for another ~400 ft. Even though I knew this terrain had been wind-loaded in days before, I was caught of guard by the heavily wind-scoured and wind-sculpted nature of the snow due to the more recent NE winds; It looked like it had already stripped the wind slab and what remained would be stable. One red flag that I should have paid more attention to, is that the snowmobile-assisted boarders who were there mentioned they triggered some small wind slabs. It looked to me that they were triggered further down where the NE wind hadn't scoured the surface and in areas that were more obviously wind-loaded or suspect (convex roll over). I didn't go back up to investigate on what layer it broke/propagated and couldn't make it out from where I was swept.