Bulletin d’avalanche

Northwest Coastal

Apr 24 – 25, 2025Avalanche Canada
Voir sur la carte
Archivé · expiré last year

Danger d’avalanche

Sat
Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
Ouvrir la carte complète

Points saillants

Daytime warming may cause wet loose avalanches and cornice failures, which could trigger buried weak layers.

Problèmes avalancheux

  • Wind Slabs

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

    Southwest wind and recent snow may have formed slabs in lee terrain features.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    3–5

    Buried weak layers from February and March continue to produce periodic large avalanches. Large loads like cornice falls are a prime trigger for them. Avalanches are most likely in north-facing alpine terrain.

  • Loose Wet

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

    Wet loose avalanches and cornice failures are possible with daytime warming. Avoid travel on sun-exposed slopes during the heat of the day and limit your travel on or below corniced ridges.

Terrain and Travel Advice

  • Be aware of the potential for large, destructive avalanches due to deeply buried weak layers.
  • Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Limit exposure to steep, sun exposed slopes, especially when the solar radiation is strong.

Confidence

Moderate

Avalanche Summary

A few small wind slabs were observed on northwest alpine slopes on Wednesday. Otherwise, small (size 1) loose wet and cornice failures were observed at treeline and alpine elevations. We suspect similar small avalanche activity could continue for the coming days.

The most recent persistent slab avalanches occurred last Sunday, which were triggered by large cornice failures. Cornices continue to be a prime suspect for triggering large, destructive avalanches.

Snowpack Summary

Around 10 to 15 cm of dry snow may be found on high elevation north aspects, with potentially deeper deposits in immediate lee terrain due to strong southwest wind. Elsewhere, a hard melt-freeze crust is likely found on the snow surface, which may soften with daytime warming.

At alpine and treeline elevations, a layer of surface hoar that formed in early March may be found around 70 to 120 cm deep. A layer of facetted grains and a crust that formed mid-February may be found 120 to 200 cm deep.

The remainder of the snowpack is consolidated.

Weather Summary

Thursday Night

Cloudy with 2 to 5 cm of snow in the alpine and light rain below. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1200 m.

Friday

A mix of sun and clouds. 20 to 30 km/h west ridgetop wind. Treeline temperature -2 °C. Freezing level 1100 m.

Saturday

Mostly cloudy with 1 to 3 cm of snow. 10 to 20 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1300 m.

Sunday

Mostly cloudy with 1 to 3 cm of snow. 10 to 20 km/h south ridgetop wind. Treeline temperature +1 °C. Freezing level 1400 m.

More details can be found in the Mountain Weather Forecast.

Régions couvertes