New wind, snow ramps up avalanche danger in West Kootenay
By Nelson Daily Editor
By Timothy Schafer, The Nelson Daily
The danger of an avalanche in the West Kootenay backcountry has crept back up to considerable Tuesday — after remaining at moderate for nearly one week — with the risk edging up to high on Wednesday, according to the Canadian Avalanche Centre.
Due to rapid loading from heavy amounts of new snow and high winds, the avalanche danger has spiraled upwards in alpine areas, said CAC’s James Floyer. At the tree line and below the tree line, the avalanche risk also is increasing, both areas hitting considerable risk by Wednesday.
More snow is expected Tuesday with light snowfall, around five centimetres, falling. Temperatures are dropping below freezing in the valley bottom, but winds are diminishing to light or moderate from the southwest.
On Wednesday, approximately 20 cm. new snow is expected, with freezing levels rising to around 1,200 metres, and strong winds from the southwest.
One small (size 1) avalanche was accidentally triggered on an eastern aspect on Saturday at around 2,000m.
“Small pockets of wind slab could also be readily ski cut, but did not propagate far,” said Floyer.
During periods of high danger, he said, backcountry skiers are asked to avoid exposure to avalanche terrain unless professional level safety systems are in place.
Areas of concern are:
• Wind slabs on steep, unsupported terrain;
• Any steep terrain loaded with new snow, especially if there is a terrain trap (like a cliff, flat bench or trees) below; and
• Slopes threatened by cornices.
Floyer said a skiff of new snow lies on top of a highly variable, wind hammered surface.
A patchy layer of surface hoar (mostly small crystals) exists buried down around 30 cm. On southerly aspects, this layer is also associated with a sun crust.
At the tree line there is a crust buried around 40 cm. from a brief rain event on Feb. 14.
editor@thenelsondaily.com
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