No Fog Bowl/China Wall (Alpental, Pineapple Pass approach)

Quick report

Summary: Skier triggered D2-D3, China Wall (above No Fog Bowl, Alpental), ENE, estimated 4600-4800’. This slide nearly carried/buried skinners on their way up to pineapple pass 6:15 pm, March 13, 2024: From the top of the big trees skin track, we observed a D2-D3 avalanche come down from “China Wall” (ENE aspect, very steep and cliffy, 4600-4800’) on to No Fog Bowl where we had just seen 2 skiers actively skinning up (towards pineapple pass/bryant’s). From our vantage point, we could only see (and hear!) a large amount of snow pouring over a cliff onto NFB, but couldn’t see the the avalanche start zone/cause, the runout, nor whether the skinners had avoided the slide. The avalanche appeared to sweep over the upper portion of the skin track we had just climbed, and likely would have carried us several hundred feet had we been a few minutes later. Burial and or injury was very possible depending on how the debris ran out through the bowl. We were shocked by the power and unexpected nature of this slide. We had identified the recent snowfall and changing conditions as a possible hazard (storm slabs and wet loose/solar affects), but given the time of day I thought any natural avalanche activity would be unlikely, and thus concluded skinning up NFB would be ok, even tho the route is not my favorite due to the overhead exposure. I should note that the reason we took the NFB skin track over our normally preferred big trees approach was convenience- we had taken the climbers right skin track up to source lake, which put us skinning around source lake and made the existing NFB skin track a very convenient option. In the future I will take the extra 5 minutes to gain the normal Big trees track and avoid the exposure. After the slide has stopped, we felt compelled to quickly transition and see if the skinners were okay, but were very unsure if there was additional hazard remaining overhead since we couldn’t determine the cause. I hopped on the common source lake radio channel (2-7) to try and establish comms with anyone in the area. I made contact with someone at pineapple pass, but no one with eyes on the situation. I did some shouting to see if the skinners could hear us. Instead I made verbal contact (but couldn’t see them) with some skiers on china wall that I learned had triggered the avalanche. Communication was very difficult because I could barely hear them. Learning that the avy was skier triggered meant that we would not enter the slidepath until the skiers had made it down. After a few minutes (wondering if the skinners were okay, or buried), the skiers made it down and were able to signal to us that the skinners were ok. From our location, we were unable to have any discussion with the skiers who triggered the slide. The skinners continued up and told us that they had to book it out of the way of the debris to avoid being carried, but they felt the debris had spread out in such a way that burial was unlikely. They noted the same may not have been true for someone higher in the track. We skied out big trees and called it a day. We did not go back to observe the start zone/crown or the debris field due to waning daylight. Above source lake we found a ~2’ of upside down snow from the recent storms, with the top 6-12” becoming dense and slabby. Areas with any hint of solar exposure had a sun crust and below 4000’ had a rain crust.