Bulletin d’avalanche

South Columbia

Mar 28 – 29, 2016Avalanche Canada
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Archivé · expiré 11 years ago

Danger d’avalanche

Wed
Thu
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Points saillants

Expect avalanche danger to rise during the day, particularly on sun-exposed slopes. Plan to start your day early and move away from large sun drenched slopes during the heat of the day.

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    2–5
    Tread cautiously near large overhanging cornices. Weak cornices could pop off naturally, potentially triggering large slabs on the underlying slope.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    3–6
    Intense spring sun and rising temperatures could reactivate buried persistent weaknesses in the upper snowpack.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Strong sunshine and warming could make recent storm slabs sensitive to triggering, particularly on southerly aspects where new snow overlies a solid crust and recent wind-loading may have occurred.

Confidence

Moderate

Weather Forecast

WEATHER SUMMARY: It will be a sunny and warm week! Temperatures will steadily climb each day with the freezing level reaching at least 2500 m by Thursday (treeline temps near +5). Ridge winds should be generally light from the NW-NE.

Avalanche Summary

Avalanche activity was minimal on Sunday. Only minor loose wet sluffing was observed, and one natural cornice fall was also reported. On Saturday there was a report of a natural cornice fall that triggered a size 3 persistent slab on a steep, rocky, north-facing slope. On Friday, just outside the northern extent of the region, there was a report of a very large (size 4) persistent slab on a large south-facing slope that was triggered by new snow loading. This avalanche likely failed on the late February interface.

Snowpack Summary

Approximately 5-10 cm of snow fell on Sunday, which will probably be sun-affected on solar aspects and wind-affected in exposed terrain from forecast northerly winds. Approximately 40-50 cm of settled storm snow sits on a melt-freeze crust buried on Mar. 22. The late February persistent weak layer is an aspect dependant mix of surface hoar, facets and/or a thick crust down around 60-110 cm below the snow surface. Commercial operators continue to see hard sudden planar results in snowpack tests, which suggests that wide fracture propagations are possible. Cornices continue to be described as large and fragile. Expect loose wet avalanches and natural cornice falls with strong solar radiation and significant warming this week.

Régions couvertes