Avalanche forecast

Banff Yoho Kootenay

Feb 13 – 14, 2015Parks Canada
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Avalanche danger

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

Natural activity is tapering, but conditions are still prime for human triggering. Conservative terrain selection is a must as we transition out of a large avalanche cycle.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    2–3
    Recent winds have created wind slabs in the lee of alpine features.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    2–3
    50 to 90 cm of storm snow exist on the January 30th interface which is a crust below 2000m and facets above. A poor bond exists at this interface and large avalanches have been observed running on this layer. Wide propagations are still possible.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3
    The base of the snowpack remains weak due to basal depth hoar/facets. Initiation of a wind slab or a storm slab may step down to trigger large avalanches in thin snowpack areas.

Weather Forecast

Continued warm temperatures with freezing levels around 2000m until Saturday AM. The winds have picked up from the west and are forecasted to be in the moderate to strong range at ridgetop until Saturday PM. A small bout of precipitation (5mm) on Friday overnight, but otherwise partly cloudy skies with a clearing trend Saturday AM.

Snowpack Summary

45-70 cm of storm snow overlies either a rain crust or facets from January 30th. This snow combined with warm temperatures has created storm and wind slabs overlying the Jan. 30th interface. The basal facet/depth hoar layers are still active in shallow snowpack areas. Little recovery overnight created isothermal conditions below 1800m today.

Avalanche Summary

Natural avalanche activity is tapering as the snowpack slowly adjusts to the new load. However, moderate to hard sudden collapse snowpack tests today in the Bow Summit area indicate skier triggering is still very possible.

Confidence

Regions covered