Bulletin d’avalanche

South Columbia

Feb 4 – 5, 2016Avalanche Canada
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Archivé · expiré 11 years ago

Danger d’avalanche

Sat
Sun
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

Watch for reactive storm slabs to form as the temperatures rise and the new snow settles. Tricky conditions still exist due to a touchy weak layer. Conservative terrain selection is critical.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    3–5
    The likelihood of triggering persistent slabs is slowly dropping, but if triggered, this layer can still produce large, destructive avalanches. A cornice failure or a small avalanche in motion has the potential step-down to a deeper weak layer.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Moderate winds, new snow and warming temperatures are expected to create touchy conditions as the new snow settles to form a slab. At lower elevations rain falling on snow will trigger widespread natural avalanche activity.

Confidence

Moderate

Weather Forecast

FRIDAY: 10cm new snow through the day, moderate to strong southerly winds, freezing level rising to 1500m. SATURDAY: up to 20cm overnight with lingering flurries through the day, moderate westerly winds, freezing level of around 1500m. SUNDAY: flurries, light westerly winds, freezing level returning to valley floor overnight before rising to 1500m through the day.

Avalanche Summary

A resurgence in storm slab activity is expected  as the new snow settles.  There is the ongoing possibility of triggering more destructive persistent slab avalanches in isolated open, unsupported terrain features at and below treeline.

Snowpack Summary

Up to 20cm of dry, low density snow fell overnight on Wednesday adding to the 40cm that has fallen in the last week. Cool temperatures have slowed the settlement of this storm snow. Moderate southwesterly winds on Thursday will have formed fresh wind slabs in lee features at treeline and in the alpine. This snow may be sitting on a crust that extends up to 1900m. In the far south of the region the new snow may also be sitting on a layer of surface hoar at treeline elevations. Deeper in the snow pack, the surface hoar layer from early January is now down 80-120cm in most places. Although this layer has become harder to trigger and is variably reactive in snowpack tests, it still has the potential for wide propagations. With that in mind, I would continue to show respect for this layer in steep, open terrain at treeline and below.

Régions couvertes