Bulletin d’avalanche

South Rockies

Mar 2, 2017Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Thu
Fri
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Strong to extreme winds and new snow are driving the danger ratings. Slab avalanches are primed for rider triggering.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1–2
    Touchy storm slabs may have a poor bond to old snow surfaces and be reactive to rider triggering. Thicker and stiffer slabs will exist on leeward slopes due to wind transported snow.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–4
    A weak layer near the base of the snowpack has the potential for large avalanches, especially in areas with minimal rider compaction or thin variable snow cover.

Confidence

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

Weather Forecast

An organized low pressure system will track across the region bringing rising freezing levels, more snow and strong winds. Conditions will remain unsettled through the forecast period. Enhanced snow amounts may be greater than forecast for Saturday/ Sunday.Thursday: Cloudy with snow 5-10 cm. Ridgetop winds strong from the SW, alpine temperatures near -7 and freezing levels 1300 m.Friday: Periods of snow 5-15 cm. Ridgetop winds light gusting to 80 km/hr from the SW, alpine high of -5 and freezing levels 1400 m.Saturday: Snow 5-10 cm. Ridgetop winds generally light with strong gusts. Alpine temperatures high of -5 and freezing levels 1400 m.

Avalanche Summary

Several explosive triggered slab avalanches up to size 2.5 were reported on Wednesday.

Snowpack Summary

Another 20 cm of low density storm snow arrived overnight bringing the recent snow totals up to 50 cm since Saturday. Strong southwesterly winds will likely transport the new snow onto leeward slopes, building thicker and stiffer slabs. The new snow may have a poor bond to previous old snow surfaces that primarily consist of stiff wind slabs, crusts and facets. The mid-pack in this region is generally well settled and strong, but the bottom third of the snowpack is composed of weak facets (sugary snow crystals). Approximately 100-120 cm of settled snow sits above the weak layer of sugary, rotten facets that developed mid- December. This remains a concern and should be on your radar especially when change is happening to the snowpack.

Régions couvertes