Bulletin d’avalanche

South Rockies

Feb 5, 2017Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Sun
Mon
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
3 · Marqué

Points saillants

New snow is creating touchy storm slabs: It's time to rein in your terrain choices and stick to simple, low consequence terrain. Avoid all overhead hazard as well - avalanches have the potential to run to valley bottom.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1–3
  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3
    Triggering deeper weak layers remains possible where hard slabs sit above weak sugary snow. This is most likely in thin snowpack parts of the region.

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

Significant snowfall through to Monday afternoon.SUNDAY: Periods of snow, accumulation 20-30cm by day's end / Light to moderate southeast wind / Alpine temperature -7MONDAY: Flurries, accumulation 10-20cm / Light to moderate southeast wind / Alpine temperature -20TUESDAY: Scattered flurries / Light southwest wind / Alpine temperature -15

Avalanche Summary

Soft slabs from the storm snow were very reactive to ski cutting and explosives control on Saturday. The size and distribution of avalanches will increase significantly by Sunday afternoon: It's time to seriously dial back the terrain use and stick to simple, low consequence terrain. The possibility of triggering the weak faceted layers deeper in the snowpack remains a concern, and storm slabs may step down to trigger larger, more destructive avalanches.

Snowpack Summary

Taking regional variations into consideration, 15-25cm of new snow typically sits on wind-affected surfaces at higher elevations. This new snow is forming touchy soft slabs on all aspects as winds have been shifting on Saturday. Below 1500 metres you may find an isolated thin breakable rain crust about 1 cm thick. The snowpack is quite variable throughout the region. In deeper areas, the snowpack appears to be well settled with isolated concerns about the mid-December facet layer buried 50-100 cm deep. In shallow snowpack areas and lower elevations, the snowpack is weak and faceted. For instance, in the Elk Valley north area near Crown Mountain last week the height of snow was 90 cm with foot penetration of 80 cm; or almost to ground. In these areas, the wind has formed isolated hard slabs above weak facets and created the potential for large persistent slab avalanches.

Régions couvertes