Avalanche Forecast

Issued: Dec 16th, 2016 4:02PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada cam_c, Avalanche Canada

Beware of wind-loaded and sun-exposed slopes where the recent storm snow has settled into touchy slabs.

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

A mix of sun and cloud for Saturday with moderate northwesterly winds and alpine temperatures around -10. Sunday should be mainly cloudy with flurries bringing around 5 cm of fresh snow by the afternoon. Ridgetop winds are expected to increase to moderate to strong westerlies and alpine temperatures around -10. Expect to wake up Monday morning with 10-15 cm of fresh snow in the mountains with an additional 5-10 cm throughout the day all falling under strong southwesterly winds. Freezing levels are expected to rise as high as 1200 m by Monday afternoon.

Avalanche Summary

No new avalanches were reported on Wednesday or Thursday. Reports from Tuesday are limited to isolated small sluffs in steep terrain in response to riders and sun-exposure.

Snowpack Summary

Around 20-40 cm of low density faceted powder overlies the previous variable snow surface from late last week, which includes hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or small surface hoar. The cold temperatures appear to be preserving the old (now buried) wind slabs from the end of last week and they still may be reactive to human triggering in isolated areas. Recent snowpack tests near Whistler gave hard but sudden results in faceted snow under the old hard wind slab. Moderate southwest winds over the weekend and more recent northerly winds have formed soft wind slabs in immediate leeward features. The widespread mid-November crust is typically down 1-2m in the snowpack. Recent snowpack and explosive tests have shown the crust to be unreactive, but it could remain a problem in shallow alpine start zones.

Problems

Wind Slabs

An icon showing Wind Slabs
Fresh soft and old hard winds slabs may be lurking on all aspects due to recent winds from a variety of directions. The recent storm snow may also have settled into a reactive slab on sun-exposed slopes.
Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.On steep slopes, pull over periodically or cut into a new line to manage sluffing.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 17th, 2016 2:00PM

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