Avalanche forecast

Sea To Sky

Dec 12 – 13, 2016Avalanche Canada
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Archived · expired 10 years ago

Avalanche danger

Tue
Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low

Highlights

It's all about the wind! Best avoid steep slopes where recent winds have blown new snow into pillowy slabs.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    Winds slabs may be lingering on all aspects due to recent winds from a variety of directions. These wind slabs may be sitting over a weak layer which could increase their reactivity.

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

Tuesday, Wednesday and Thursday: Cold and dry and mostly clear throughout the period. Treeline temperatures in the -8 to -10C range, winds light, initially from the northeast, becoming easterly on Wednesday. Some cloud appearing Thursday.

Avalanche Summary

On Sunday, a small cornice was human-triggered and loose snow avalanches were noted in steeper terrain. Otherwise no notable avalanche activity occurred. On Saturday, ski cutting was producing very soft slabs, in leeward terrain features and a few natural size 1 loose avalanches were also observed.

Snowpack Summary

Around 20cm of new low density snow has buried the heavily wind affected surfaces from the strong outflow winds last week. The old surface is highly variable and may include hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or small surface hoar. Expect the new snow to be bonding poorly with this interface. The cold temperatures appear to be preserving the old wind slabs from the end of last week and they still may be reactive to human triggering in isolated areas. In high elevation terrain, moderate southwest winds over the weekend may have redistributed some of the new storm snow and soft slabs may exist 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.

Regions covered