Avalanche rocks Blackcomb, triggers backcountry caution Spring slides especially dangerous By Chris Woodall A "class-3" avalanche down to Lakeside Bowl on Blackcomb's south side should serve as a clear warning of backcountry dangers as spring melts into summer, say mountain ski patrollers. The Lakeside Bowl slide was powerful enough to physically crunch a car and break trees. "They're always a big event for us," says Blackcomb ski patroller Tim Smith about the size of avalanches here. The Lakeside Bowl slide occurred sometime during the night or early morning, April 1-2, says ski patroller Anna Brown. It was in out-of-bounds territory beside Xhiggy's Meadow, but was an impressive sight that drew skiers and boarders to see the power of Mother Nature. There are five classes of avalanche, as graded by Canadian ski patrollers, based on a European system. A class-3 avalanche has a mass of 1,000 tons and travels about a kilometre. A class-4 avalanche is a rare event in this part of the world, Smith says, but it involves 10,000 tons of snow and could crush railway cars. The Duffey Lake area had a class-4 slide this year that left a seven-metre-high crown line. It slid down a mountain, across one of the Joffre lakes and up the other side. A class-5 slide moves 100,000 tons of snow and ice and could destroy a village. Ski patrollers have been busy blasting mountain crest cornices within resort boundaries during the past couple of weeks. Sounds of blasting echoed sharply down the valley last weekend. "It sounds louder than in winter because the blasts are near what is now open rock and the sound travels farther in clear weather," says Smith of the muffling effects of January's deep snowpacks, and frequent presence of cloud or fog. Ski patrollers use explosives between 10 and 50 kilos in size to crack cornices, Smith says. "Explosions in wet snow don't do much because it absorbs the blast," Smith says. Impressive snow/ice boulders the size of small vehicles were visible at the base of the Couloir Extreme. "Cornice control results are classified as avalanches, too," Smith explains. "They could certainly hurt people on the way down, but that's why we control the cornices." "There's not a lot of big hangers left, but there are in the backcountry," warns Brown. The backcountry is no place to fool around in the spring, Brown says. "The thing I want to alert people to about the backcountry is that cornices are obvious and you don't want to walk underneath them," she says. Slab slides are different. And sneaky. "Slabs of snow can slide on rain crusts — laid down back in November — as the slab gets heavy and wet," Brown says. "When you cross the slopes, take note of the time of day, how warm it is and what kind of slope you're traversing."