Greeting to all Avalanche students, those who did the online program, and those who wanted to but couldn’t.
Here we are at the beginning of May and while restrictions are starting to loosen up, it seems as if the snow will melt a lot before we can get back into the mountains and do the field work as we had hoped. The plan was to use the Tioga Pass area, but the road is not open yet.
So, it looks as if that will have to wait until next winter. But we will get it done. We have lists of everyone who did the online session and that will count as Day 1 for the sessions of 2020 and 21. When we get snow, call us up or email us.
What Do You Think?
An Incident to Remind You What we Talked About
- Preparation: Getting information from home
- Planning: Gathering information along the way & selecting terrain
- Teamwork: Working together
- Riding: Putting the plan into effect.
- Debriefing: How did the day go?
A party of two skiers, one male, one female, both in their mid to late twenties, set out around 9:30am on April 29th to ascend, then ski a prominent canyon on the northeast side of Independence Peak, above the Onion Valley Rd near the Kearsarge Pass trailhead. After skinning up the chute for ~1.5 hours and gaining a couple thousand feet, at ~11:00am they stopped on the edge to transition from skinning to booting. While they both had their packs off they heard then saw an “explosive fast moving” avalanche release approximately 300-500′ above them. With no time to react, both were caught up in the moving snow but the male was able to grab on to some rocks until the moving snow passed. The female, though, was carried out of sight down the canyon.
The male subject, now missing his skis and backpack, was able to move down the canyon and eventually found his partner (and half of a ski) on the skier’s left edge of the debris, unburied but with rib and lower back injuries severe enough that she was unable to continue out, having been carried approximately 1,000’ by the avalanche.
Details of the initial contact are not clear, but shortly after 11:00am the Inyo County Sheriff received a call concerning some sort of slide on the Kearsarge Pass Road, and the Inyo County Search and Rescue team was deployed along with resources from the CHP including CHP helicopter H40, Inyo County Sheriff and CAL Fire. The total response included over 40 personnel. The Inyo County Sherrif and a Deputy were first on scene and were able to boot up to the skiers. Upon arrival of the SAR team, the SAR team snow safety officer and other team members evaluated avalanche conditions and concluded that the area continued to have high avalanche danger conditions. In addition to a successful rescue of the subjects, a goal was to minimize the number of respondents exposed to the avalanche hazard, so the SAR team and CHP determined that a helicopter hoist offered the fastest and safest means of extricating the injured subject. H40 was able to insert one SAR team member at the subject’s location and the patient was subsequently evacuated by the helicopter and taken to Southern Inyo County Hospital.
The avalanche started in steep NE facing terrain around 10,800′, presumably as a loose snow slide. At around 10,400′ a large wet slab avalanche released on a deeper weak layer with an estimated 2’-4’ crown. The total slide length was about 2,500’, and measured a D2.5/R3. Rapidly warming temperatures, parly cloudy skies, and a weak overnight refreeze of the snowpack were all likely contributing factors. Weather from nearest remote weather sensor – Charlotte Lake (10,400′): -4/29: Low Temp of 35F at 4am. Temp rose from 41F to 51F between 8:00am – 8:45am. 56F at 11:00am, up to a high of 58F at 12:00pm. -Although the previous day high temperatures rose to 60F on 4/28, the skies were clear, and low temperatures the night before dropped to 33F. The party said that winds at the time of avalanche were light.
Additional details and comments: The party estimates that ski penetration while they were skinning (mostly in the shady side of the chute) was between less than an inch to barely 2″, but that on the sunny side it appeared to be softening more. They overestimated the superficial surface refreeze that they felt was deeper. They both had transievers on, but their rescue equipment in their packs was swept away by the slide, as they were in the middle of transitioning. Had the slide occurred minutes earlier when they were still skinning, or minutes later when they were booting with packs and skis on their backs, both of their outcomes could have been much worse. The skiers had ~5yrs and ~12 years of backcountry experience, no formal avalanche education, but quite a bit of informal education from experienced partners.
So, what do you think?
If you want to learn more about avalanches visit our Avalanche School web page and register for a program.