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Avalanche Forecast

Dec 16th, 2016–Dec 17th, 2016
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: Sea To Sky.

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

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.

Avalanche Problems

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