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Backcountry Advisory

As of Wednesday, Dec. 15

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For the areas adjacent to Whistler-Blackcomb

Alpine: Considerable

Treeline: Considerable

Below Treeline: Moderate

While facet crust weaknesses linger near the bottom of the snowpack, the instability on the crust that formed on Dec. 10 and was buried on Dec. 13 is the main concern for riders. Easily triggered size one to two soft slab avalanches have been running within the 25 to 30 centimetres of wind-loaded storm snow and on the crust. Continued mild temperatures and light precipitation could further stress this upper crust weakness by increasing the load over the crust.

The Dec. 10 rain event was a sufficient trigger to produce some very large slab avalanches with crowns in excess of 1.5 metres. Large triggers could produce more results like these. The crust is best developed as a hard ice crust between 1,900 and 2,050 metres, and a 10 to 20 cm windslab above 2,100 metres.

Shallow areas of the snowpack, steep lee features in the alpine (especially over summer ice) and at treeline should all be carefully assessed for any instability. Remember that there are numerous terrain traps out there with the relatively shallow snowpack.

Conditions are changing quickly, with the possibility of more precipitation and mild temperatures looming over the next few days. Stay in tune with the weather and check the current hazard ratings at www.avalanche.ca or 604-938-7676.

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