Avalanche forecast

Kootenay Boundary

Dec 24 – 25, 2011Avalanche Canada
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Avalanche danger

Mon
Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Click on the 'Forecaster's Blog' link below for more discussion on how to travel safely under the current conditions.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Watch out for wind slabs below ridge crests, behind terrain breaks, and in cross-loaded gullies. Wind slabs are expected to build in size over the next few days.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–3
    If sufficient new snow builds up, we can expect to see avalanches failing on a persistent weak layer which exists in the upper snowpack.

Confidence

Fair - Due to variable weather conditionsfor the entire period

Weather Forecast

Sunday: Generally light snowfall with a pulse of moderate snowfall expected in the afternoon. The freezing level will rise to 800m by afternoon. Strong south-westerly winds at ridge top.Monday/Tuesday: Further light precipitation with moderate-strong south-westerly winds. The freezing level should slowly rise in the early part of the week.

Avalanche Summary

No new avalanches have been reported.

Snowpack Summary

Recently developed surface hoar and near-surface facets are getting gently buried by light snowfall, potentially creating a weak interface which could become reactive with enough new load from snow and/or wind-transport.Other buried surface hoar layers exist in the upper 15-25cm (with sudden test results on these layers in some locations). Soft and hard wind-slabs can be found on certain slopes in the alpine and around treeline. Generally light snowfall amounts are forecast for the region over the next few days. Without the certainty of heavy or rapid loading, it's hard to know when the weight of new snow building over buried weaknesses might reach a tipping point. Areas with locally heavier snowfall should reach this point sooner. Facets at the base of the snowpack could create a deep persistent slab problem that deserves attention in shallow snowpack areas on planar rocky slopes.

Regions covered