Bulletin d’avalanche

Northwest Coastal

Jan 16 – 17, 2025Avalanche Canada
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Archivé · expiré 2 years ago

Danger d’avalanche

Sat
Sun
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

Deep instabilities are present and have produced large avalanches during the storm. The recent storm snow will need time to settle and stabilize, and human triggering is likely.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    2–3.5

    The persistent slab avalanche problem is and has resulted in large to very large avalanches (up to 3).

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2

    Watch for newly formed and reactive storm slabs within the new snow. Potential remains for slabs to step down to deeper persistent weak layers.

Confidence

Moderate

Avalanche Summary

On Tuesday, numerous naturally triggered persistent slab avalanches (up to size 3) were reported. A skier remotely triggered a size 1.5 persistent slab from 50 m away.

Natural avalanche activity may taper but human-triggered avalanches are likely on Thursday.

Snowpack Summary

Another 30 + cm is expected Wednesday bringing storm snow totals up to 80 cm over the past few days. Strong to extreme west through southwest wind has created widespread wind effect, with deeper deposits of snow on leeward slopes.

Down 70 to 120 cm a layer of surface hoar, facets, or a thin crust exists.

A persistent weak layer of surface hoar and facets overlying a crust is buried 120 to 150 cm deep. This layer remains reactive, producing large and dangerous avalanches.

Weather Summary

Wednesday Night

Snow 10 cm. 30 to 60 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 700 m.

Thursday

Snow 5 to 10 cm. 20 to 50 km/h southwest ridgetop wind. Treeline temperature -6 °C. Freezing level valley bottom.

Friday

A mix of sun and cloud, possible flurries up to 5 cm. 25 to 50 km/h northwest ridgetop wind. Treeline temperature -9 °C. Freezing level valley bottom.

Saturday

Cloudy. 10 to 30 km/h north ridgetop wind. Treeline temperature -8 °C. Freezing level valley bottom.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Avoid freshly wind-loaded terrain features.
  • Keep in mind that human triggering may persist as natural avalanches taper off.

Régions couvertes