Bulletin d’avalanche

South Coast Inland

Apr 14 – 15, 2018Avalanche Canada
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Archivé · expiré 8 years ago

Danger d’avalanche

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

More snow forecasted in the south of the region Saturday night will keep the hazard at Considerable. Observe for the bond of the snow with the underlying crust before committing into avalanche terrain. Be particularly cautious if the sun comes out.

Problèmes avalancheux

  • 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 in the north of the region. Be particularly cautious around upper treeline and alpine terrain on shady aspects.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2.5
    Recent snow has created slabs that are not bonding well to a crust. The slabs are particularly reactive in lee features, as the snow fell with strong south winds. Slab and loose avalanches will become more likely on south slopes if the sun comes out.

Confidence

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

Weather Forecast

SUNDAY: 10 to 20 cm snowfall in the south of the region early-morning, otherwise a mix of sun and cloud with late-afternoon snowfall, light northeast winds, alpine temperature -4 C, freezing level 1500 m.MONDAY: Cloudy with snowfall, accumulation 15 to 20 cm, light west winds, alpine temperature -5 C, freezing level 1400 m.TUESDAY: Mostly cloudy, light west winds, alpine temperature -5 C, freezing level 1500 m.

Avalanche Summary

Numerous small wind slab avalanches were triggered by skiers on Friday, 20 to 35 cm deep and on northerly aspects in alpine terrain.  These were running within the recent storm snow on the melt-freeze crust. They were reported as easy to initiate, indicating that the bond between the new snow and the crust is poor.

Snowpack Summary

Around 30 to 50 cm of snow has fallen in the region between Thursday and Saturday.  This snow overlies a thick and hard melt-freeze crust.  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