Local Avalanche IncidentsMarch 3rd, 2013 - Kicking Horse Drainage, Takhinsha Mountains
Weather and Snowpack Summary:
1.34" of precipitation fell in Haines from Feb. 27th - Mar. 2nd.
Daytime high temperatures in the 3 days leading up to the accident were 1-4 degrees Fahrenheit higher than the previous week, but there was no strong warming trend. The main change in weather was a clearing of the clouds that had persisted all week.
Clouds cleared on the 2nd of March bringing some of the first strong solar radiation of the season. There was a hard freeze on the morning of the 3rd, followed by strong solar radiation once again. The 3rd brought the largest diurnal temperature spread (17 degrees F) of the last 36 days in Haines. High temperatures in the alpine on the 3rd were estimated to be in the low to mid 20's F.
Details of the Incident:
Four clients and one lead guide were dropped off on a ridgeline above the Garrison glacier in the upper Kicking Horse valley approximately 10 miles southwest of Haines.
While the group was standing on the ridgeline, the snow they were standing on collapsed underneath them with a big 'whomp', an audible fracture, and them a 'boom'. Four of the five people in the group fell with the collapsed snow ledge onto and down the steep slope below. The section of ridge that broke was estimated at about 40 feet long and about 10 feet wide.
The riders tumbled approximately 600 to 1000 vertical feet before coming to rest close to each other. No one was buried in debris, and at least one person deployed an airbag (this person was remarkably uninjured).
After the fall, one person was found unresponsive, CPR was initated, and he was transported to the Haines medical clinic where he was pronounced dead. Of the three others in the fall, two had serious injuries. The snowboarder who survived sustained multiple femur fractures. One skier had fractures to his hip and nose, and lacerations and contusions on his face/head.
The helicopter that had dropped them off was in the area, and assisted with the rescue.
There was another group of recreational backcountry skiers approximately 35 miles away that remotely triggered a large cornice break that same afternoon (March 3rd, approx. 3pm). It is worth noting that this second incident was in a more continental zone with a much different snowpack. The group was on a summit when they felt the snow settle about 3 inches with a whumph. It was heard to travel downslope to a very large cornice feature (approx. 10m tall and 600m long), which then broke into pieces the size of small buildings and tumbled onto the approx. 35-degree slope below, triggering an avalanche rated as D3.5 R4. The hard slab slide ran to the ground, and was about 1m deep. The group involved in this second incident remarked at how strong the sun was that day, and that this was the first day they had used sunscreen all winter. Despite the sunshine, they were caught off-guard by the cornice collapse, as the day was still cool with temperatures in the 20's F in the high alpine.