Bulletin d’avalanche

Sea To Sky

Apr 7 – 8, 2016Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Sat
Sun
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

Extremely warm conditions with strong sun will drive the Avalanche Danger. Be alert to conditions that change throughout the day, and watch your overhead hazard. Large avalanches may run farther than expected.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    Recently formed wind slabs are expected to settle and gain strength with the warm conditions but for the short term I'd remain extra cautious of steep, wind-loaded pockets in the high alpine.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–5
    Large cornices may become weak with afternoon warming and sun exposure. They can be destructive by themselves, and may also become the trigger for a slab avalanche on the slope below.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Loose wet sluffing is likely on sun exposed slopes during the heat of the afternoon. Very warm conditions may increase the size and run length of natural sluffing.

Confidence

Moderate

Weather Forecast

A ridge of high pressure will remain the dominant feature for the weekend. Sunny conditions are expected for Friday with moderate southwest winds in the alpine and afternoon freezing levels around 3200m. Mainly sunny conditions are expected for Saturday and Sunday with light alpine winds and afternoon freezing levels around 3000m.

Avalanche Summary

On Wednesday, natural loose wet avalanches up to size 1.5 were reported. Skiers and explosives were triggering wind slabs up to size 1.5 in leeward features and on steep rolls. Small natural cornice falls were reported in the afternoon. With warm and sunny conditions continuing, spring avalanche problems are expected to be the primary concerns. Loose wet avalanches and large cornice falls are expected throughout the forecast period. Lingering wind slabs may also still be a problem on high elevation north aspects.

Snowpack Summary

20-40cm of recent snowfall overlies a mix of old surfaces that formed as a result of last week's big warm-up. The old buried surface includes hard crusts on high elevation solar aspects, settled dry snow in high north-facing alpine terrain, and moist snow everywhere else. The recent snow has been shifted by strong southerly winds into fresh wind slabs in wind-exposed terrain. With forecast solar radiation and warm temperatures, most surfaces will transition to a daily melt-freeze cycle, while recently formed wind slabs will linger on high north-facing slopes. Below the new snow, the snowpack is generally strong and well-settled. Cornices are huge and will become weak with warming and solar radiation.

Régions couvertes