Bulletin d’avalanche

Coquihalla

Mar 7 – 8, 2023Avalanche Canada
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Archivé · expiré 4 years ago

Danger d’avalanche

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

Wind slabs may remain reactive on a variety of aspects at treeline and above.

Sheltered terrain at lower elevations will likely offer the best and safest riding.

Problèmes avalancheux

  • Wind Slabs

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

    Wind slabs may remain reactive on a variety of aspects at treeline and above.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1.5–3

    A crust formed in mid-January can be found down 90 to 130 cm. In areas around the Coquihalla, facets can be found sitting on the crust. This layer is of greatest concern with large triggers, such as a cornice fall, or by first triggering a smaller avalanche that could step down to this interface.

Confidence

Moderate

Avalanche Summary

A naturally triggered glide slab avalanche was reported on a west aspect on Sunday.

On Saturday, explosive avalanche control work resulted in numerous very large avalanches. They included storm, persistent, and deep persistent slab avalanches and were size 3-4. They initiated on a variety of aspects in the alpine.

Snowpack Summary

Up to 100 cm of snow last week and shifting strong winds formed wind slabs on a variety of aspects at treeline and above. These slabs are sitting on either hard surfaces or small facets.

A melt-freeze crust formed in mid-January is buried up to 170 to 190 cm deep at treeline and above. Though still a concern, it appears to be gaining strength.

Weather Summary

Monday Night

Partly cloudy / Light south ridgetop wind / Low temperature at treeline -13 C / Freezing level valley bottom.

Tuesday

Mix of sun and cloud / Light southeast ridgetop wind / High temperature at treeline -2 C / Freezing level 1100 m.

Wednesday

Mix of sun and cloud / Light southeast ridgetop wind / High temperature at treeline -2 C / Freezing level 1200 m.

Thursday

Mix of sun and cloud / Moderate southeast ridgetop wind / High temperature at treeline -3 C / Freezing level 1100 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be especially cautious as you transition into wind affected terrain.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
  • Sheltered low elevation terrain will likely offer the best and safest riding today.
  • Avoid exposure to slopes that have cornices overhead.

Régions couvertes