Bulletin d’avalanche

South Coast Inland

Apr 11 – 12, 2018Avalanche Canada
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Archivé · expiré 8 years ago

Danger d’avalanche

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

The calm before the storm!Watch for wind slabs in the immediate lee side of ridgelines. They may be reactive to human triggers.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2
    Reactive wind slabs likely exist in isolated areas at treeline and above on leeward slopes. At lower elevations, loose wet avalanches may occur as the daytime temperature rises.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3
    Cornices are very large and fragile, especially when the sun comes out. Give them a large berth while on ridges and avoid traveling underneath them, as they may trigger avalanches on slopes below.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3
    A weak layer buried 50 to 100 cm is still surprising people and producing large and destructive avalanches. Be particularly cautious around upper treeline and alpine terrain on shady aspects, where this layer is most likely to be a problem.

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Thursday: Cloudy with some sunny periods. New snow up to 5 cm and strong southwest winds at ridgetop. Freezing level 1300m.Friday: Stormy. New snow 15-25 cm through the day. Ridgetop winds strong from the South. Freezing levels 1400 m. Saturday: The storm continues, bringing another 15-20 cm. Ridgetop winds strong from the southwest. Freezing levels 1500 m. Less snow amounts expected in the Northern areas of the forecast region.

Avalanche Summary

On Monday, a MIN report from the Duffy Lake area showed a skier accidental size 2 storm slab from a north aspect at 2700 m. Please check out the report here. No new observations on Tuesday or Wednesday, however, alpine observations seemed limited due to the weather. Expect the avalanche hazard to rise through the forecast period with new snow and wind.

Snowpack Summary

Up to 10 cm of new snow overlies moist snow surfaces. At higher elevations, this overlies slabs formed from last weekends snow that fell with strong southwesterly winds. On ridges, cornices are reported to be large and fragile. At low elevations below treeline, recent rain has created moist or wet snow conditions.A weak layer consisting of surface hoar, facets, and/or a melt-freeze crust from late March is now buried about 50 to 100 cm. This layer is spotty in its distribution. It is mostly likely to be problematic on west, north, and east aspects between 1900 m and 2250 m.The mid and lower snowpack are well-settled and strong.

Régions couvertes