Avalanche forecast

Northwest Coastal

Feb 9 – 10, 2012Avalanche Canada
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Avalanche danger

Sat
Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    3–6
    Large cornices are looming over some slopes which could act as a trigger for large, deep avalanches if they collapse.

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–4
    Winds are forecast to change direction and increase in strength, potentially leaving wind slabs on slopes facing all directions. New wind slabs may bond poorly to they surfaces they land on. Take extra care on steep or convex terrain.

Confidence

Good - -1

Weather Forecast

Overnight Thursday: Snow amounts up to 10cm. As the front weakens on Friday only few flurries are expected. Freezing levels near 1000m. Ridgetop winds will be light from the SW, with alpine temperatures near -3. Saturday/Sunday: A weakening front may bring 2-5cms later Saturday night. Clear, sunny skies and lower freezing levels expected on Sunday.

Avalanche Summary

One natural cornice fall triggered a size 2 on the slope below. Reporting persons mentioned it may be 48hrs old. Suspect the Jan 20th facet layer, which may still be susceptible to large triggers. Isolated wind slabs have been triggered by skiers on steep rolls near treeline.

Snowpack Summary

Variable wind slabs have been reported. A melt-freeze cycle has created a crust which is harder and thicker the lower in elevation you go. On north aspects in the alpine, near surface facetting has kept snow dry and loose. Surface hoar of size 1-4mm is likely to get buried by incoming snow on Thursday night and Friday. A facet layer buried on Jan 20th still exhibits hard, sudden planar results in isolated snowpack tests and avalanches are occasionally failing on this layer with large triggers. It's about 120-150cm deep in the snowpack. Large cornices have the potential to act as a trigger for deep avalanches on the slope below.

Regions covered