Bulletin d’avalanche

South Rockies

Jan 1 – 2, 2022Avalanche Canada
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Archivé · expiré 5 years ago

Danger d’avalanche

Mon
Tue
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

Watch for fresh wind slab formation if you notice the wind pick up. Check out the latest Forecaster Blog for tips on managing the persistent slab problem in this region.

Problèmes avalancheux

  • Wind Slabs

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

    Fresh wind slabs are likely to form at upper elevations as the wind picks up this weekend. Lingering reactivity may also be observed in older wind slabs on a variety of aspects.

  • 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.

Avalanche Summary

Wind slabs were touchy on Thursday when natural and remotely triggered size 2 wind slab avalanches were reported on easterly aspects at alpine and treeline elevations.

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

Confidence

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

Weather Forecast

Friday night: Clear. Light northwest wind. Alpine temperature around -27 C.

Saturday: A mix of sun and cloud. Moderate northwest wind. Alpine high around -18 C.

Sunday: A mix of sun and cloud with flurries starting in the afternoon. Strong southwest wind. High of -10.

Monday: 5-10 cm new snow. Moderate southwest wind. High of -5 C.

Snowpack Summary

Recent 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.

Terrain and Travel

  • Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
  • Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
  • 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.

Régions couvertes