Avalanche forecast

Sea To Sky

Dec 16 – 17, 2012Avalanche Canada
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Archived · expired 14 years ago

Avalanche danger

Tue
Wed
Alpine
4 · High
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2–6
    Deep and touchy wind slabs exist on many slopes due to changing winds. Be alert for these below ridge crests, behind terrain features, and in cross-loaded gullies.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1–4
    In areas protected from the wind, fast-moving sluff could knock you off your feet or carry you into a terrain trap.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period

Weather Forecast

Sunday night: Strong SE winds. Freezing level at surface. 10-15 cm snow.Monday: Strong winds changing from SE to W. Alpine temp lowering to -10. A few cm snow.Tuesday: Light to moderate SE winds. Alpine temp -7. Very light snow. Wednesday: Light SE winds. Alpine temp -11. 20 cm snow.

Avalanche Summary

Recent activity has been limited to a few small (size 1) soft slab avalanches in immediate lee features and small loose snow avalanches in steep terrain. Observations from early last week included several old size 2-3 avalanches, primarily from northerly aspects in the alpine. These events may have released on a weak layer of surface hoar, now down over a metre deep.

Snowpack Summary

Up to 50 cm of new snow may have buried a thin layer of surface hoar in some areas. Recent winds have been stiffening the low density storm snow and forming reactive slabs in exposed lee terrain. Below the recent storm snow weaknesses, the snowpack is well settled and strong. A layer of surface hoar that formed during late November has been found intact or decomposing in some locations down a metre or more. The early November crust/facet combination near the base of the snowpack seems to be dormant, at least in deep snowpack areas where it is buried too deeply by a stiff snowpack to be affected by light triggers on the snow surface.

Regions covered