Prior to the incident on Thursday, April 11, the summit of Mount Washington recorded 1.9” of snow on Tuesday and 1.1” on Wednesday. Winds from the NW blew the snow into wind slabs in lee locations. The Bottom Line section of Thursday’s avalanche forecast read:
Temperatures have continued to fall since yesterday resulting in a sketchy mix of wind scoured, bulletproof ice crust and fresh wind slabs. Areas that contain these wind slabs have MODERATE avalanche danger due to the possibility of a human triggered avalanche.
The forecast went on to describe the potential for sliding falls on icy slopes adjacent to the wind slabs and to describe the uncertainty of warming and softening of the snow, which would improve conditions on icy surfaces but possibly increase the chance of avalanches in some areas. The avalanche problem section of the forecast for the day contained relevant information and identified wind slab as the primary avalanche problem:
Wind slabs up to size D1.5 or even size 2 may be possible in east facing bowls like Tuckerman, Huntington, Gulf of Slides and possibly the Great Gulf. They’ll be thickest in upper start zones and will likely be in the stubborn to reactive range. Expect a poor bond to the icy bed surface until proven otherwise, especially in steeper terrain and on unsupported slopes.
Skiing conditions are prone to changes in the spring as temperatures swing up and down past the freezing point. A Moderate avalanche danger rating is frequently considered manageable by educated backcountry skiers. The reality of skiing during any periods of avalanche danger is that absolute certain stability does not exist. In this case, a 1-5 cm layer of well preserved rimed snow particles and some rounded graupel lay between the icy bed surface and the slab built from the prior two days of wind blown snow. Nicholas’ ski tracks on the surface of the snow above the crown line lie over a convex lens shaped area of icy crust. Stability tests performed on the crown the day following the accident, including at the assumed point of avalanche initiation, yielded moderate but variable results like we find much of the winter. Wind slabs, like some other avalanche problems, are characteristically variable in thickness, distribution, and sensitivity. This complexity is compounded by the fact that any skiing in our alpine and treeline areas necessarily takes you into open terrain that is often ripe with the necessary ingredients to avalanche…a steep slope, a wind slab, followed by a trigger. Due to these wind slabs in our terrain, skiing a steep slope on a wind slab is the norm all winter. Unless you wait for isothermal conditions to develop in the spring, it’s hard to avoid the uncertainty that comes with skiing on these wind slabs. The mitigation for these uncertain risks comes in terrain choices and safe travel techniques. In this case, Nicholas tried for several regular partners, all of whom were either busy or did not like the combination of wind slabs and icy slopes.
Anyone with a bit of avalanche education may question the terrain selection that Nicholas made that day, but many more would admit to making similar choices in similar conditions. The fateful mistakes that Nicholas made were skiing alone and skiing above a terrain trap that carried significant consequence. The slope which released contained a slab just barely large enough to bury a person; add a funnel and a narrow stream bed to this and the avalanche debris became more than enough to bury Nicholas. Though surviving an avalanche on that day above that terrain trap is far from certain, having a partner skilled in companion rescue may have saved Nicholas in this case, assuming effective companion rescue occurred immediately after the avalanche. One other notable factor in this accident was the fact that at least three parties observed and later reported seeing what appeared to be a fresh crown line in Raymond Cataract. No one made the 5-10 minute diversion to look for clues or do a beacon search of the debris where a ski and pole were on the surface 75’ uphill of the burial site.
As backcountry skiing, and more specifically steep skiing in avalanche terrain, continues to grow in popularity, we at MWAC continue to hope that people will get educated by taking avalanche courses as well as bring a partner and the appropriate skills and equipment into the terrain. For many of us, Nicholas’ death gives us an opportunity to reflect on our own risky behaviors. Nicholas, like many of us in the ski community, loved to ski and had taken many of the steps necessary to stay safe while doing it. He had avalanche education under his belt, he carried a ski repair kit, extra layers, plenty of water, and a first aid and survival kit. He was wearing a beacon and carrying a probe and shovel. Unfortunately, no one was watching from a safe location while he skied the slope, ready to rescue him before time ran out.