Avalanche forecast

Kootenay Boundary

Jan 19 – 20, 2014Avalanche Canada
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Avalanche danger

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

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–4
    Wind slabs continue to grow at higher elevations. In some areas up to one metre thick. Warm alpine temperatures may result in loose wet avalanches on southerly aspects, or cornice falls, triggering deeper instabilities.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    2–5
    Recent storm snow may not be bonding to the surface hoar and melt-freeze crusts that developed before the storm. Storm slabs are more likely in areas sheltered from the recent strong winds. Forecast warm temperatures may result in easier triggering.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    3–6
    This problem is more likely in areas that had a shallow snowpack during the cold arctic outbreak. Loose wet avalanches or cornice falls may trigger deeply buried weak layers resulting in large destructive avalanches.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

Synopsis: A strong ridge of high pressure over BC and western Alberta is doing a good job of blocking Pacific moisture from the region. An inversion will see temperatures higher in the alpine than at treeline.Overnight: Nil precipitation. Winds light to moderate from the west, freezing level at valley bottom.Monday: Nil precipitation. Winds light at ridge tops, freezing level in the alpine to 1300m.Tuesday: Nil precipitation. Winds light at ridge tops, freezing level in the alpine to 1400m.Wednesday: Nil precipitation. Winds light at ridge tops, freezing level in the alpine to 1400m.

Avalanche Summary

Recent explosive controls reported results in storm snow only. Sluffing in steep terrain, snowballing and pinwheel activity on steep solar aspects.

Snowpack Summary

Wind continues to redistribute surface snow throughout the region. The snowpack varies widely, but appears to be deeper in the north and east. Basal facets continue to be a concern where wind slabs and storm slabs have added load above these weak layers. The forecast very warm alpine temperatures may result in periods of rapid warming of the wind and storm slabs above weak layers. Strong solar radiation may cause moist or wet loose snow avalanches or cornice falls in the alpine resulting in large additional loads above deeply buried weak layers. Surface hoar has been reported forming on protected north and east slopes along with facetting of the surface and storm slab in protected locations.

Regions covered