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Cold air gone by Sunday

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Backcountry advisory

As of Wednesday, Nov. 29

 

Alpine: CONSIDERABLE

Treeline: MODERATE

Below Treeline: LOW

Travel Advisory: North winds during the recent cold weather have redistributed the surface snow, resulting in areas of windslab. These windslabs are often obscuring rocks and other hazards and are reacting easily to skier traffic. A weather system is expected to build more windslabs into alpine start zones by Thursday.

Windward areas are not well covered as the storms that brought us all this snow came with very strong winds and scoured any exposed terrain.

Below 1,700 metres there is a noticeable rain crust below the upper one half metre of loose snow. While this crust covers many of the rocks, many rocks and holes are still lurking beneath the surface.

Avalanche Activity: Ski testing has been producing easily triggered size 1 slabs. Cornices are large and unsupported and have been fracturing well back from the edge while being approached.

Snowpack: Most of the current snowpack came with two big mild storms in early November. These storms left considerable snow in lee areas above treeline. They left a thinner wet snowpack below 1,800 metres that is now found as a buried crust. Windward areas have a much thinner snowpack than lee areas, especially in the alpine where the depth can vary from 0.5 metres to 3 metres.

The recent north winds have formed areas of windslab in the alpine that are lying over loose snow. Easy shears are being found below this windslab. Moderate to hard shears in the mid pack are persisting at the various layer boundaries. Isolated areas of small surface hoar may also be found below Thursday’s storm snow.

The surface weaknesses have resulted in small avalanche activity. Explosive testing has only resulted in isolated activity at the deeper shears.

Weather: Thursday’s storm should give way to clearing on Friday and occasional cloud with possible flurries over the weekend. The cold air should move out of our area by Sunday and we can expect some mild weather systems by the middle of next week.

Remember that there are still many exposed early season hazards so take it easy out there. Watch for winch cats and snowmobile traffic if you re-enter the ski area after operating hours.

Call 604-938-7676 or surf to avalanche.ca or whistlerblackcomb.com for updated information.

Blackcomb Snow Safety

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