Bulletin d’avalanche

South Rockies

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

Danger d’avalanche

Thu
Fri
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

New snow, wind, and warming temperature have created dangerous avalanches conditions. Stick to conservative low-angle terrain and avoid travel in the alpine.

Problèmes avalancheux

  • Storm Slabs

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

    Continued loading from new snow and wind has formed storm slabs on all aspects. As the snow stacks up, storm slab size and sensitivity to triggering has increased. 

    Even in lower snowfall areas, don't discount the moderate to strong southwest winds, loading lee slopes around ridge crests, as well as cross-loaded features. Sticking to sheltered lower angle terrain out of the alpine is a good bet.

Confidence

Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.

Weather Forecast

There is some uncertainty and model disagreement around forecast snowfall amounts.

Monday Night: Flurries 5-20 cm, moderate to strong southwest wind, rising freezing levels around 2000 m.

Tuesday: Light snowfall 5-10 cm, moderate to strong southwest wind, freezing levels 2000 m.

Wednesday: Light snow overnight into Wednesday. Winds become light from the southwest, freezing levels around 1300 m. 

Thursday: Overcast, trace of snow possible, light southwest wind, freezing levels 1300 m.

Avalanche Summary

A natural size 2 storm slab avalanche was spotted by the South Rockies field team just north of Sparwood on Monday. In the southeast of the region operators reported size 1-1.5 skier controlled storm slabs and loose wet avalanches.

Snowpack Summary

Snowfall amounts have varied substantially throughout the region with the southern areas receiving the greatest values. Totals of about 30 cm in sheltered areas were reported by the end of the day on Monday. Wind loading from moderate to strong southwest wind should also be anticipated as there is now snow available for transport. New snow will need time to bond to a variety of old surfaces such as firm wind-pressed snow, sun crust on solar aspects, surface hoar, and potential cold weak crystals on shaded aspects.

The middle and lower snowpack are generally well consolidated, with a crust/facet layer from early-December found near the bottom of the snowpack. It is currently considered dormant but could become active later this season. Check out the forecaster blog for more information. 

Terrain and Travel

  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Make conservative terrain choices and avoid overhead hazard.
  • Stick to well supported, lower angle terrain.

Régions couvertes