Avalanche forecast

Banff Yoho Kootenay

Apr 4 – 5, 2014Parks Canada
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Archived · expired 12 years ago

Avalanche danger

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

Cornices have grown and are touchy - Several natural failures observed in past 2 days with snow volumes up to size 2. Keep an eye on overhead hazard. Best skiing on due North aspects. Avoid thinner snowpacks where basal facets can be triggered.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Wind slabs 15-25 cm thick were found in immediate lee terrain and failed easily in snowpack tests.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3
    Very low confidence in this basal layer of depth hoar as daily avalanches size 2-3 and large whumphs continue to be reported. Mainly a problem on the East side of the Continental Divide or in shallower snowpacks in Kootenay Park.

Weather Forecast

Mainly cloudy along the Continental Divide and mix of sun and cloud East of the Divide. Winds to remain moderate with strong gusts from the West.  Freezing levels to remain at valley bottom, but start to rise Monday night.  Watch for solar related avalanche activity or cornice failures, especially on Sunday.

Snowpack Summary

New wind slabs 15-25 cm thick in the immediate lees. Western areas such as Emerald and Field have a deep and stable snowpack. Contrast this with the Lake Louise, Hwy 93 N, & Sunshine areas, where a there is a weaker snowpack with sudden collapse very easy compression results on the basal depth hoar. A crust exists on all but N aspects.

Avalanche Summary

Everyday for the past week, there have been avalanches, size 2-3 or large whumphs failing on the facets at the base of the snowpack. They were triggered by cornice, explosive, skier, or prolonged periods of sun. These observations were in the Lake Louise, Hwy 93N, and shallow areas in KNP. Several cornice failures to size 2 observed in past 2 days.

Confidence

Regions covered