Bulletin d’avalanche

Northwest Coastal

Mar 28 – 29, 2014Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Points saillants

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–4
    Strong Easterly outflow winds have developed hard wind slabs in the alpine and at treeline.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–5
    The early March persistent weak layer is buried deep enough to produce large avalanches when triggered. Periods of solar radiation may increase the sensitivity to triggering this buried weak layer.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    3–6
    The early February persistent weak layer is buried deeply in the snowpack and continues to be a concern. Heavy loads like cornice falls or storm slab avalanches in motion may trigger this weak layer resulting in very large avalanches.

Confidence

Fair - Wind effect is extremely variable

Weather Forecast

Synopsis: Zonal flow directs the bulk of the moisture stream at the South Coast while the North Coast remains high and dry.Saturday: Freezing Level: 500 - 1000m Precipitation: Trace; Treeline Wind: Light, E | Ridgetop Wind: Moderate, SESunday: Freezing Level: 200 - 800m Precipitation: Nil; Treeline Wind: Light, SE | Ridgetop Wind: Light, VariableMonday: Freezing Level: 400 - 1200m Precipitation: Nil; Treeline Wind: Light, Variable | Ridgetop Wind: Light, Variable

Avalanche Summary

No new avalanches were reported Thursday.

Snowpack Summary

Strong Easterly winds have been reported to have caused intense wind transport of the recent storm snow, developing pockets of wind slab on various aspects in the alpine and at treeline. Forecast cool temperatures are not expected to promote much settling or bonding of the near surface layers, and probably not much change to the persistent weak layers. The deeply buried persistent weak layers continue to provide moderate to hard sudden planar results in snow profile tests, but may be deep enough to require a heavy load for triggering. The March weak layer is a combination of hard wind-scoured slab surfaces in exposed terrain, facets and/or surface hoar in sheltered and north aspects, and sun crust on steep solar aspects. This layer is widespread throughout the forecast region and is now buried close to 150cm in most parts of the area. A late January/early February crust/facet/surface hoar combo is now buried 200 cm or more.

Régions couvertes