On Saturday, April 15th, 2023 a skier triggered a soft slab avalanche around a foot deep on a high elevation NW aspect. The skier was caught and carried around 2,000′ over rocks and one large cliff band. The skier was not buried when they came to rest and is ok despite minor injuries. This was on the upper face of Captain’s Chair in the Lynx Creek area. This point is also called East Groundhog Peak on some maps and is at 4462′.
Please read below for the account passed to us from the skier involved and another member of the group. We greatly appreciate these skiers for sharing their experience and we are so grateful everyone is safe.
|Number Caught/Carried?||1||Number Partially Buried?||0|
|Number Fully Buried?||0||Number Injured?||1|
After speaking with the persons involved, this is most likely an older soft wind slab. The weak layer is unknown. The slab was described as soft; when skied prior to the avalanche, it felt like soft settled powder. The crown was estimated at 8-12" thick and roughly 200' wide. Loose snow was entrained on the descent and the debris ran for around 2,500 vertical feet. Daytime warming can make slabs slightly more reactive even if the surface snow is still dry, this could have played a role, but that is unknown.
A group of 4 snowmachine-skiers headed up Lynx Creek from the Johnson Pass trailhead around 1230pm on Saturday, April 15. They used snowmachines to access the ridge to East Groundhog Peak, 4462' (commonly referred to as Captain's Chair), in order to ski it's NW face. The up-route used was in the drainage to the south. This route traveled through a similar aspect and elevation, albeit a bit lower, with no signs of instability seen.
The first skier skied the face, just to the north (skier's right) of the predominant Captain's Chair chute, without incident. The skier noted only soft settled powder, good skiing, and sluff management. The second skier made three turns then on the fourth saw cracks shooting out and knew they had triggered an avalanche. They attempted to ski out to the right and made it within 10 feet of the edge of the slab before being caught completely. Once caught the skier let go of their poles and pulled their airbag. They tumbled ~2000' down the face, through and over rocks and over one large cliff band lower on the slope. Both skis ejected at some point along with one glove. During the fall, the skier was sucked under the moving debris at times and snow was being forced into their mouth, which they had to clear with a hand multiple times. The skier's GPS recorded a speed near or just over 40mph. The skier came to rest on top of the debris and after a moment was able to radio they were ok. They suffered minor injuries. Both the skier's poles, glove and one ski were recovered.
After the avalanche, the 3rd skier retraced the up-route back to meet the group along the Lynx Ck trail. The fourth skier did not access the ridge and watched and assisted the group from below. They were well out of the way when the avalanche occurred. After regrouping and assessing injuries, they made their way back to the parking lot on their snowmachines.
No signs of instability were seen prior to the avalanche on similar aspects/elevations. There were wet loose avalanches on southerly aspects however.
High clouds with some sunshine.
Ridgetop winds were light from the east.
Temperatures were warm, in the mid 20'sF.
At the time of the avalanche, ~3pm, the group reported it felt like a warm afternoon.
Soft settled powder, dry snow.
CNFAIC Comments: The skier credits their helmet and fan operated airbag for keeping them from sustaining worse injuries during such a long and violent ride. The group had been assessing the snow conditions all day and did not see any red flags on slopes without sun effect. They were aware of the consequences of the terrain they were in and had all their safety gear working. They also exposed one person at a time and had good radio contact with all members. Following these good practices stacked the odds in their favor. Last, this is an example of how being in big and steep rocky terrain adds more committing elements with potentially sever consequences even when the initial avalanche isn't all that big.