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!

Four Injuries

USFS Snow Rangers and the Mount Washington Volunteer Ski Patrol assisted with four injured visitors. Each patient was able to evacuate themselves without further assistance beyond Hermit Lake. The first patient was a participant in the Inferno pentathlon who fell during the ski leg and dislocated his shoulder. The dislocation was reduced and the shoulder immobilized. The second patient fell while climbing Left Gully, sustaining abrasions to both forearms as a result of his efforts attempting to self-arrest without an ice axe. The third patient fell while climbing above Lunch Rocks. He also dislocated his shoulder; this dislocation was reduced and immobilized for his walk to Pinkham.

The fourth incident of the day is worthy of further analysis. This skier began to descend the Lip in the late afternoon when he realized the surface was much more firm and steep than he had anticipated. At some point before descending, he dropped his ski poles down the Lip, stepped out of his skis, and began to climb back upward to the ridge. He traversed over to the top of the Sluice, where conditions were not much better than in the Lip. Upon descending, he lost control and began a tumbling fall that ended just short of Lunch Rocks. He was able to walk himself down the Snow Ranger Quarters at Hermit Lake where he was examined by Snow Rangers and the MWVSP. It was determined he may have suffered a minor concussion but was otherwise all right. At the request of the caregivers, he returned later in the evening for a follow-up evaluation before spending the night at his shelter. This incident involves a few common hazards we see each spring. First, when the sun begins to set behind the ridge, the snow surface can quickly turn very icy and slick. Second is descending an unknown route without first climbing it to determine its nature. The Sluice is every bit as steep as the Lip, but also has cliffs and a runout into Lunch Rocks making falls especially precarious. Skiing at the top of your ability in unfamiliar terrain without poles and with a large pack can be very challenging; sometimes walking down can be a good option. Kudos to the patient’s friends for encouraging him to get checked out by trained personnel.

Avalanche Accident in Tuckerman Ravine

Two climbers were involved in an avalanche accident in Tuckerman Ravine. The accident took place on a sunnier-than-expected Saturday early in the spring skiing season. The weather forecast had called for mostly cloudy skies, summit temperatures falling to 15F, and winds ranging from 25-40mph. The morning avalanche advisory discussed the snowpack staying frozen for most of the day, with the best chance of warm soft snow being on south-facing aspects. Northerly aspects were expected to remain cold and frozen through the day. DZ and TF, both athletic and experienced mountaineers, were climbing the steep snow route known as “Dodge’s Drop” unroped, each with two technical ice axes and crampons. They had recently climbed Hillman’s Highway and were familiar with the terrain on the Boott Spur Ridge. The plan was to climb the route to access the hiking trails to the summit of Mt. Washington, then descend through Tuckerman Ravine.

For much of the climb, the surface conditions were refrozen springtime crust. The party reported they were enjoying the climbing conditions when on this surface. At times, they encountered small areas of newer softer snow but this surface was more difficult to climb, so they opted for the old surface when possible. Nearing the top of the climb, they encountered an isolated pocket of relatively new slab. The upper climber (DZ) reported he was unable to swing his axes through the new snow into the crust, his boots were getting full penetration when kicked into the snow, and the snow was fully supporting his weight. He stated that he decided to move left to get around the slab both for stability reasons and for the easier climbing on the crust. As he was working himself toward the edge of the slab the avalanche released.

DZ recognized what was transpiring and was able to see the fracture line propagate upwards from his feet to a point about 6-8 feet above him. The fracture then propagated outward and the slab began to slide downhill. TF was about 10 feet below and slightly to the side of DZ. He had both ice tools sunk into the snow. The initial slab, which DZ was entrained in, pulled out more snow above TF. He attempted to hold on against the force of the slab pouring over him but he was eventually pulled off his stance. Both individuals were carried downhill, and each reported being airborne at some point. DZ stated he was impressed by how much time he had during the course of the slide to figure out what to do. He said he was unsure of whether to try to self arrest or swim to stay on top. At one point he discarded one tool and attempted to self arrest with the other. He felt the pick engaging the crust, but was unable to stop himself. He also reported that during this time he saw his partner slide past him, indicating he at least managed to slow himself to some degree. The avalanche carried them over a small cliff (hence DZ reporting being airborne for “3 heartbeats”) and down into a treed slope below. The compressive force of the snow impacting the slope below the cliff was quite strong; it ripped both ice axes out of TF’s hands and they both felt as though their clothes and gear were also being pulled loose. They came to rest in the trees with most of the debris though some of the debris continued to run farther downslope. Both individuals came to rest on top of the snow; no excavation was required.

The avalanche was witnessed by a crowd in the courtyard of Hermit Lake Shelter’s caretaker’s cabin. The commotion alerted a Snow Ranger (Jeff Lane) who saw the climbers sliding into the trees. The caretaker of the shelter site was climbing nearby in Hillman’s Highway; he established communication with the climbers who yelled to him that they were all right. The caretaker continued over to the climbers to assess their injuries more thoroughly. Meanwhile a Snow Ranger and one member of the Mount Washington Volunteer Ski Patrol headed uphill to tie in with the party. DZ suffered a small laceration on his forehead, a broken pinky finger, sprained ankle, some ligament damage in his knee, bruising on his thigh and shin, and abrasions on both elbows. The abrasions were caused by sliding on the icy crust while wearing only a synthetic t-shirt. TF reported that he lost his vision momentarily when they came to rest but regained it soon after. He also suffered multiple abrasions on both arms and hands, ligament damage in one knee, and a bruised pelvis. The climbers were escorted to the Snow Ranger cabin at Hermit Lake where they were more thoroughly assessed and treated. From here, they were transported to the parking lot in the USFS Snowcat, where they were released into their own vehicle for transportation to a local hospital.

Snowpack information: On the night of April 6, 2009 Mt. Washington received a soaking rain transitioning to mixed precipitation and snow. Total water equivalents from this event were 0.71” recorded on the summit, with 1.2” of this coming as snow. Lower on the mountain at Hermit Lake the USFS manual snowplot precip can had collected 1.45” water equivalent with 1.9” of this falling on the storm board as snow. This rain event soaked the snowpack then refroze, giving us a baseline below which there have been no stability issues. Overnight on April 8, the summit recorded 0.4” of new snow. This new snow was not sufficient to raise the avalanche danger above Low for any of the nearby forecast areas in the days following this relatively small snowfall. It’s worth noting the ability of the wind on Mt. Washington to transform seemingly insignificant snow totals into deeper slabs. One excellent example came earlier this month. On April 4, the summit recorded 0.6” new snow. The following morning USFS Snow Ranger Brian Johnston found slabs averaging 9-10” in sheltered lee areas, with one slab measuring 24” deep. Although the snowfall responsible for this avalanche was only 0.4”, winds had been able to develop deeper slabs in isolated areas. This slope has a NNE aspect, and recent weather had been warm but not sufficiently warm to create a melt freeze cycle on northerly aspects. This isolated pocket was able to remain cold and dry while similar slabs in nearby areas with different aspects had been skied numerous times without incident in the days between the snowfall and the avalanche. The fracture line from this avalanche was estimated to average 6” deep and 30-40 feet wide. The slab depth at DZ’s high point was at least 12”.

Summary: These two climbers were incredibly fortunate. This route is generally considered “no-fall” territory due to numerous rocks, cliffs, and trees in the fall line. The total vertical drop of their fall is estimated to be around 800 feet. They managed to pass through the rocky section of the fall unscathed, with the injuries being sustained only after being carried into the trees. Ironically the avalanche which caused their fall likely helped protect them from more significant injuries as they probably rode on the debris cushion to their resting point. Falling this distance with crampons on, ice tools in hand, and going over small cliffs usually concludes much worse. That they were able to walk themselves down from an incident such as this is remarkable to say the least.

From an avalanche perspective, the climbers had chosen a reasonable route. Although Dodge’s Drop is not one of the forecasted areas on the mountain it is adjacent to Hillman’s Highway which is one the 8 forecasted slopes and gullies of Tuckerman Ravine. All 8 areas were forecasted at “Low” at the time of the accident and where heavily skied without incident. Some isolated pockets of instability did exist but between skier compaction; skiers cutting up the continuity of these pockets; and solar gain baking out any fracture propagation potential they became inconsequential by late morning. Dodge’s is a northern facing slope which makes it slow to react to sunny days as it does not receive direct solar gain. Slabs on these aspects often require higher ambient air temperatures for rapid settling compared to southern facing slopes which react very quickly to solar radiation. Using an avalanche forecast issued for an adjacent slope to your intended ascent/decent as a tool is a smart use of your available resources. In addition to the forecast discussion points however always consider how your intended route might harbor different instability issues. The slab they triggered was small and isolated; if this were in a forecasted area it would be considered an “isolated pocket.” The climbers recognized the hazard when they encountered this pocket and were attempting to mitigate it as best as they could when the fracture initiated. Many valuable lessons can be learned from this event, two are offered here as they are not uncommon occurrences on Mt. Washington. First, it’s important to recognize that “Low avalanche danger” does not mean “No avalanche danger”. Isolated pockets of instability can be present under a Low rating and you should be capable of recognizing and assessing this hazard for yourself. Second, it underscores the importance of being able to assess hazards before dropping in over the top of them. In this instance, there was at least one skier known to be hiking up Hillman’s with the intention of descending Dodge’s Drop. It’s quite likely that this skier would have triggered the pocket if the climbers had not. Whether the hazard is avalanches, crevasses, undermined snow, etc., it’s always a good idea to assess for hazards before descending from above.

Snowboarder caught an edge in the Lip – torn ACL

A snowboarder caught an edge in the Lip causing him to tumble about 300 feet to the floor of the ravine. The victim tore his ACL during the fall. USFS Snow Rangers and members of MWVSP splinted the injured leg and he was able to walk with assistance to Hermit Lake, where he was loaded into the USFS snowcat for transportation to Pinkham Notch.