Three Human Triggered Avalanches- Center Bowl

This was a very warm and busy day with three human triggered avalanches, three head lacerations, and two lower leg injuries. Avalanches were a concern as recent snowfall had developed slabs in lee areas a couple days earlier. These slabs had been subject above freezing temperatures for a full day and night, leading to the Lip, Headwall, and Bowl being posted at Considerable on Friday the 24th and Moderate danger for the 25th. Additionally, the potential for falling ice from the Sluice and Headwall areas was another cause for concern.

The first patient of the day fell in the center Bowl area and injured his lower leg in the fall. One Snow Ranger and one Ski Patroller had to briefly delay hiking to him as a safety measure. When the area became sufficiently clear of traffic, they brought a litter to the patient, loaded him into it, and quickly moved to a safer location for further assessment. The second patient fell in the upper Chute and injured his knee and thigh during the fall. As a safety measure, lookouts were posted above the patient as well as off to the side. Both patients were splinted and transported to Pinkham with the help of numerous bystanders who were willing to help out.

All three head lacerations were bandaged and the patients were able to walk themselves down to Pinkham. One cut the back of his head when he attempted a backflip on a man-made jump in the floor of the ravine. A second fell off a cliff while skiing the left side of the Headwall. The third fell while carrying his skis down a steep section between the Little Headwall and the Lower Snowfields. He slipped and fell into another person’s ski edge, causing a facial laceration.

As mentioned, three human triggered avalanches took place, all in the center Headwall area. This area, as well as the Bowl and Lip (including the Sluice) were rated at Moderate avalanche danger. The avalanche advisory for the day discussed the unusual avalanche issues for the day related to continued warming of recently developed slabs over an older more stable bed surface. Despite the Moderate rating, numerous people were skiing almost every line imaginable in the Headwall area. Just prior to noon, the first slab avalanche was triggered by sluff created as a person attempted to descend the center Headwall. A little more than an hour later a second and slightly smaller slab released farther left of the first slide. This snowboarder was carried with the debris but not buried. The third avalanche involved hangfire that remained between the first two slides; the trigger for this one was able to remain on his board and not be carried with the slide. In addition to the Headwall, we were concerned about stability issues in the Lip and Sluice. Stability was decreasing as the day progressed due to increased melting; however, skier compaction of the Lip from the day before and early on this day helped stabilize this area before the decreasing strength of the slab reached the critical threshold. Somehow, the Sluice did not see any traffic except for a couple riders at the very end of the day. The avalanches that occurred are not the usual type for Mt. Washington. As an example, the second slide released after many people, perhaps up to 30, had already descended the same area that day. Warm slabs can still retain their cohesiveness while the meltwater breaks down their tensile strength. We believe this is what happened to the slabs that released here. In these cases the trigger was human but it also could have been entirely natural.

It is difficult for us, as professional avalanche forecasters, to fully understand the human factors involved in the decisions visitors were making throughout the day. We believe there existed a wide variety of attitudes and perceptions of the hazards on the mountain this day. The vast majority of visitors listened to our advice and made safe decisions. Others listened to our safety messages then allowed other human factors to take priority. There were also some who understood the hazards and willingly chose to accept the risk involved. We also believe there are others who truly did not understand the magnitude of risks they were dealing with. In this case, several key pieces of bulls-eye data existed (i.e. recent avalanche activity in one part of the Headwall gives a clear indication that snow may be unstable on other similar slopes). We are thankful for the relatively low number of injuries on such a busy day and feel lucky that no injuries resulted from the three avalanches. We want to emphasize that our role in Tuckerman Ravine each spring goes beyond helping out those who are injured. We firmly believe that with good information visitors will make better and safer decisions. We are here to provide information and guidance that will help you have a positive experience. Please seek us out anytime you have questions about what hazards exist on a given day!