Bulletin d’avalanche

Northwest Coastal

Apr 6 – 7, 2017Avalanche Canada
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Archivé · expiré 9 years ago

Danger d’avalanche

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

Exposed terrain has been walloped by strong winds. Watch for cornices and wind slabs at higher elevations.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2
    Very strong winds on Tuesday night and Wednesday likely formed reactive wind slabs in the lee of exposed terrain.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3
    Large cornices may become weak with daytime warming and have potential to trigger slabs on the slopes below.

Confidence

High -

Weather Forecast

FRIDAY: Cloudy with sunny periods and isolated flurries, moderate southeast wind, freezing level up to 1300 m after an overnight freeze.SATURDAY: 5-10 cm of new snow, light southeast wind, freezing level around 1300 m.SUNDAY: Cloudy with light flurries, moderate south wind, freezing level around 1200 m.

Avalanche Summary

Several natural and explosive triggered wind slabs were reported on Wednesday in north and west alpine features (up to size 2.5). Several avalanches were triggered by cornice falls earlier in the week, including one size 2.5 persistent slab avalanche on the February weak layer. A snowmobiler had a close call with a cornice fall on the weekend at South Douglas (click here for MIN report).

Snowpack Summary

Touchy wind slabs may still exist at higher elevations, as Wednesday's storm delivered 15-20 cm of snow above 1000 m with strong to extreme winds. Extensive wind affect is expected in exposed terrain. An overnight freeze will likely form a crust at lower elevations that will deteriorate with the heat of the day. A weak layer of facets and crusts is buried 100-150 cm deep. The layer has been unreactive recently, but a heavy trigger such as a cornice fall or intense warming may still be able to trigger it.

Régions couvertes