Avalanche forecast

Northwest Coastal

Mar 14 – 15, 2012Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    Forecast strong winds and new snow will form fresh wind slabs on lee slopes.
  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–6
    Cornices are reported to be very large and potentially unstable at this time. A cornice fall could be destructive by itself, and may also act as a trigger on the slope below.

Confidence

Fair - Intensity of incoming weather is uncertain on Thursday

Weather Forecast

Thursday: moderate snowfall starting Wednesday evening and continuing through Thursday - moderate to strong southeast winds switching to southwest throughout the day - freezing level @ 600m Friday: light snowfall - light to moderate southwest winds - freezing level @ 600m Saturday: trace amounts of snow with possible clearing skies - light and variable winds - freezing level @ 600m

Avalanche Summary

A size 3 natural cornice failure was observed in the region on Wednesday. A size 1 skier triggered soft wind slab was also reported.

Snowpack Summary

Sporadic strong and variable winds have redistributed light amounts of recent storm snow into thin wind slabs that most commonly exist at treeline and in the alpine.In the northern part of the region two persistent weak layers are on the radar of some operators: Surface hoar buried at the beginning of March is as much as 70cm deep. The early February persistent weak layers (surface hoar, facets, crusts) are over a metre down. Although triggering persistent weaknesses has become less likely, persistent slabs would be destructive in nature, particularly below treeline on isolated and sheltered steep terrain where buried surface hoar may be preserved. Cornices in the region are reported to be very large and potentially unstable.

Regions covered