Bulletin d’avalanche

North Rockies

Mar 13 – 14, 2023Avalanche Canada
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Archivé · expiré 4 years ago

Danger d’avalanche

Wed
Thu
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

New snow and moderate south wind may form reactive wind slabs at treeline and above.

Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    10-15 cm new snow and moderate south wind has formed small wind slabs on lee aspects at treeline and above.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    2.5–4

    A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth, but large triggers such as cornice failures or smaller avalanches in motion have the potential to produce very large avalanches with surprisingly wide propagation. Suspect terrain for human triggering includes steep, shallow, and rocky terrain where the snowpack transitions from thin to thick.

Confidence

Moderate

Avalanche Summary

A few small (size 1) naturally triggered wind slabs on steep northwest aspects at treeline and above were reported on Sunday.

Snowpack Summary

10-15 cm new snow and moderate south wind has formed small wind slabs on lee aspects at treeline and above.

Below the new snow, is generally hard surfaces from extensive wind effect or a thin sun crust on steep, sunny slopes.

The middle of the snowpack is generally well settled and strong.

A weak layer of large and weak facets is found near the base of the snowpack. This layer is of greatest concern in shallow snowpack areas in the north and east of the region.

Weather Summary

Monday Night

Partly cloudy with isolated flurries; 0-3 cm / 30 km/h southwest ridgetop wind / Low temperature at treeline around -16 C

Tuesday

Mix of sun and cloud / 30 km/h southwest ridgetop wind / High temperature at treeline around -10 C

Wednesday

Mostly cloudy with isolated flurries; 0-5 cm / 30 km/h southwest ridgetop wind / High temperature at treeline around -9 C

Thursday

Sunny / 30 km/h southwest ridgetop wind / High temperature at treeline around -6 C

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • Sheltered low elevation terrain will likely offer the best and safest riding today.

Régions couvertes