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In the spring a young man’s thoughts turn to the backcountry — and avalanches By Amy Fendley From the Grouse Grind to Galtuer, Austria, the winter of 1998-99 has seen some devastating avalanches that have buried towns, killed dozens of people and turned many mountainous areas into time bombs. Yet Whistler, which is experiencing one of its heaviest snow years in memory, has so far been relatively incident free. There have certainly been lots of avalanches in the Whistler and Blackcomb regions this season, both natural and human-induced. And last week a group of people were caught in a minor slide on Whistler, but all managed to escape unharmed. But as we move into March and the urge to get out beyond the ski area boundaries strikes more and more people, is the backcountry a lethal man-trap just waiting to grab the first skier or boarder who makes a wrong turn? "The snowpack is really quite solid, but that doesn’t mean nothing is going to happen," said Jan Tindle, an avalanche forecaster for Whistler Mountain. "There’s always the risk of an anomaly. In the spring there are weaknesses when it begins to rain a lot, but I see a low probability of that happening here this spring." The reason the snowpack in the Whistler area is relatively solid is because it has built up through successive storms this winter without any major underlying weakness or flaw. That compares with three winters ago, when temperatures soared early in the season, depositing rain on top of snow. That then froze, creating a slick surface that never bonded well with the snow that piled up on top of it. That weakness lay buried in the snowpack across virtually the whole province all that winter. Blackcomb avalanche forecaster Tony Sittlinger agrees with Tindle and says he sees a single strata weakness as a much less significant threat this year. "The deeper layers are pretty good," says Tindle. "There’s some weakness in the upper 100 cm, but the deep snowpack is stable. When it’s really warm the snow settles and if it’s cold the snowflakes retain their shape and the layer becomes pretty airy." The Canadian Avalanche Rescue Dog Association cautions that even though the snowpack is relatively stable, avalanche activity has been ongoing in the new snow layers, a pattern that has been seen throughout the winter. Although there have been a lot of natural, explosive and skier-triggered releases during and directly after the storms, and then rapid settlement and a trend towards stabilization, CARDA warns that the seemingly trouble-free snowpack that Whistler has been blessed with so far this winter could be harbouring weaknesses below the surface. In most areas the weaknesses are bridged over by a strong slab above. However, in some oddball piece of terrain the weakness could be nearer to the surface and also associated with a potential trigger point on the slope, such as a rock outcrop. It may fail where the slab is thin, pull into the meatier part of the slope and create a potentially deadly avalanche. But even if the snowpack as a whole is relatively stable, avalanche forecasters make two points: conditions can change rapidly in the spring and backcountry conditions may be different from in-bounds areas where ski patrol have been practising avalanche control all winter. "We use explosives, ski cutting and advise skiers when to avoid the terrain," Sittlinger said of in-bound areas. "If we can’t reduce the hazards to satisfactory levels we close the area." The avalanche forecasters for Whistler and Blackcomb will throw 80 to 100 kilograms of explosives every time it snows heavily, or if there is not much new snow but a lot of snow deposited by winds. But in the spring, things change. "When the temperature begins to rise, the changing of the snowpack from a solid to a liquid state poses an inherent threat of instability," says Sittlinger. "It is difficult, but not impossible to control. You can test to see if it will run, and an hour later it will." Tindle says that when the sun comes out and there are hoards of people, warming causes the snowpack to become more fluid, wanting to move more. Increasing hours of daylight in the spring bring directional solar aspects that need to be considered when assessing avalanche hazards. Alpenglows become more intense in the spring from 6 to 8 p.m. By March, Blackcomb faces early morning sun. If an area gets a lot of sun then gets more snow, like Rainbow for example, there could potentially be serious problems. Before jumping into a slope, CARDA advises being mentally prepared for a slide. If the slope does go, it is important to anticipate where it is going to take you; which way is your best escape route if you have any control; are your partners out of the danger zone and do they have you in sight; and are all members of your party carrying the appropriate rescue tools. If you have to rely on an outside search party to dig you out of the avalanche, chances are that you’ll be another body recovery.

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