Avalanche forecast

Sea To Sky

Jan 6 – 7, 2012Avalanche Canada
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Avalanche danger

Sun
Mon
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–5
    Watch for sensitive wind slabs lurking below ridgecrests, behind terrain features and in cross-loaded gullies.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    3–7
    More likely to be triggered from thin slab areas, from heavy triggers like cornice falls, or from storm or wind slab avalanches stepping down to deeper weaknesses.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–5
    Watch for touchy storm slabs on steep unsupported terrain features.

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Saturday: 6-8cm of snow arriving late in the day / moderate to strong southwest winds / freezing level at 1600mSunday: 15-20cm of snow / strong southwest winds / freezing level climbing from 1600 to 2000m throughout the dayMonday: 15-20cm of snow / moderate southwest winds / freezing level lowering to 1000m throughout the day

Avalanche Summary

Widespread natural avalanche activity up to Size 3 was reported on Wednesday. Fresh storm and wind slabs, as well as deeply buried persistent slabs remain sensitive to human triggers.

Snowpack Summary

Weaknesses within and under the 60-100+cm of storm snow will need some time to settle and strengthen. Persistent weaknesses remain a concern in the many parts of the region. Buried surface hoar on sheltered treeline slopes and below and facets with associated crusts in exposed treeline and alpine areas are probably down well over a metre in most places.Basal facets remain a concern in shallow snowpack areas, especially where the snowpack is overlaying summer firn on slopes that have already produced deep persistent slab avalanches and have been reloaded.Wind-loading has resulted in highly variable slab thicknesses with the potential for fractures triggered in highly sensitive thin slab areas to propagate into highly destructive deep slab avalanches. Furthermore, weaknesses within the slab create the potential for step-down fractures.A recently buried thin hard rain crust that extends into alpine elevations is also providing a poor bond to overlying deep hard wind slabs.

Regions covered