Bulletin d’avalanche

Northwest Coastal

Mar 25 – 26, 2013Avalanche Canada
Voir sur la carte
Archivé · expiré 14 years ago

Danger d’avalanche

Wed
Thu
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
Ouvrir la carte complète

Points saillants

Avalanche danger may spike on slopes that are getting warmed by sunshine or warm temperatures. Be alert for changing conditions throughout the day.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–4
    Watch for new wind slabs forming behind ridges and ribs and in cross-loaded gullies. Cornices are also large and untrustworthy.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–7
    A layer of surface hoar buried down 50 cm was especially touchy last week. While the likelihood of triggering is slowly dropping, it can be triggered from a distance, propagate across large distances and create surprisingly large avalanches.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

Tuesday-Thursday: No snow. Light to moderate SW winds. Alpine temperatures near -4.

Avalanche Summary

Naturally-triggered wind slabs and loose moist avalanches have been observed over the last couple of days. Ice fall also triggered size 2.5-3 avalanches near Bear Pass and other areas. On Saturday there was a report of a size 2 avalanche, triggered from a distance by a snowmobile. This slide probably failed on the March 9 surface hoar. Many skier-triggered and skier-remote avalanches of size 1-3.5 were reported last week, with the bulk of events failing on the March 9th surface hoar layer down around 50 cm.

Snowpack Summary

Recent new snow is settling with the influence of warm temperatures. Wind slabs may be found at alpine and treeline elevations. A layer of surface hoar (buried March 9th; now down about 40-60 cm) has been found at all elevations. It’s slowly becoming less touchy, but professionals are keeping a wary eye on it. Triggering this layer is becoming a low probability but high consequence problem. Check out the Forecaster's Blog for related discussion. A second surface hoar layer, buried on March 18, is also reported to be gaining strength. The mid snowpack is generally well settled and strong. Cornices are large and untrustworthy, especially when the sun is out.

Régions couvertes