Bulletin d’avalanche

South Rockies

Dec 30 – 31, 2021Avalanche Canada
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Archivé · expiré 5 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

Lingering wind slabs may remain reactive to human triggers on lee features at treeline and above.

Check out the latest Forecasters' Blog for tips on managing the ongoing Persistent Slab problem in this region.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2.5

    Strong westerly winds have created fresh wind slabs on lee features at treeline and above.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3

    A persistent slab problem formed by a crust down 60-100 cm has created a low likelihood, high consequence scenario that is difficult to forecast.

    Avoid likely trigger spots such as steep, rocky slopes with a shallow or thin to thick snowpack.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Be aware of the potential for large avalanches due to the presence of a persistent slab.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.

Confidence

Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Weather Forecast

THURSDAY NIGHT: Partly cloudy / Light west wind / Low of -30

FRIDAY: Sunny / Light north wind / High of -22

SATURDAY: Increasing cloud in afternoon / Moderate northwest wind / High of -19

SUNDAY: Cloudy with flurries; 3-5 cm / Strong southwest wind / High of -11

Avalanche Summary

Natural and skier triggered size 2 wind slabs were reported on Thursday.

Explosive control work on Wednesday produced numerous size 3 wind slab avalanches in the alpine on primarily northwest aspects.

Snowpack Summary

Strong westerly winds have created fresh wind slabs on lee features at treeline and above.

The most notable layer of concern in the snowpack is a crust that was formed in early December and is now down 50-120 cm. Activity on this layer has been sporadic. It has generally been triggered on steep, rocky slopes, with a shallow or thin to thick snowpack.

This layer has created a low likelihood, high consequence scenario which is best managed through conservative terrain choices and disciplined backcountry travel techniques.

Régions couvertes