Avalanche forecast

Northwest Coastal

Apr 1 – 2, 2012Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–5
    Forecast strong winds and new snow will create fresh windslabs on lee terrain.
  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    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

Weather Forecast

Monday: light to moderate snowfall continuing overnight - strong to extreme southeast winds - freezing level at 800m Tuesday: light snowfall - strong southeasterly winds - freezing level at 700m Wednesday: moderate to heavy snowfall starting tuesday evening - strong southwest winds - freezing level at 700m

Avalanche Summary

On Saturday sluffing to size 2 was observed in steep, sun-exposed terrain. There has also been an increase in glide crack activity on solar aspects, especially where rocky ground cover is smooth and slabby. I expect a spike in wind slab avalanche activity with forecast weather on Monday.

Snowpack Summary

Light amounts of recently fallen snow override a variety of old surfaces that include wind slab, crusts and spotty surface hoar. Spring-like conditions have existed over the past several days forming crusts on solar aspects at all elevations that become moist under sunny skies during the day. Melt conditions exist on all aspects below 1000 m, with no significant re-freeze. Below all this, down 60-120 cm exists a very spotty surface hoar/ facet interface. Operations from the field noted no recent activity on this layer. I suspect it's becoming dormant, but would be suspicious of large triggers like cornice fall, or under the weight of a sled and it's rider in specific areas. Cornices in the region are reported to be very large and potentially unstable.

Regions covered