A high avalanche danger hangs over the West Kootenay Boundary backcountry as instabilities in the snow pack have been compromised by a recent dump of 70 centimetres of storm snow.
The Canadian Avalanche Centre (CAC) is warning skiers and snowboarders about a high avalanche risk across the region this week, with the danger easing somewhat from high to considerable as the week wears on.
Alpine areas are at the highest level of warning, while areas in the tree line are rated at a considerable risk. The risk is moderate to low below the treeline.
“Instabilities may ... be triggered naturally or by the weight of a person,” said forecaster Peter Marshall in a briefing from the CAC.
He noted that “whumpfing,” shooting cracks and recent avalanches are all strong indicators of an unstable snowpack. Several natural and skier triggered slab avalanches up to size 2 were reported throughout the region last weekend.
“Stick to simple terrain and be aware of what is above you at all times,” he advised.
Up to 70 cm. of moist storm snow has fallen in the past several days, accompanied by generally moderate south-southwest winds, forming wind slabs in exposed leeward terrain. Marshall said below the new snow is a layer of surface hoar or a thin crust.
A frontal system is expected to move through the West Kootenay Boundary this weekend bringing moderate snow, very strong winds and rising freezing levels. Unsettled and cooler conditions are expected in the wake of this system.
For those who are still learning to read the snow, in January, Rossland Search and Rescue is expected to stage their annual Avalanche Awareness Days on Red Mountain in conjunction with the CAC.
The snows had reached a critical level in the upper reaches of the West Kootenay on Wednesday. The Department of Highways closed the Kootenay Pass Summit in both directions for a 10-kilometre stretch because of avalanche control.