Bulletin d’avalanche

Howson

Jan 12 – 13, 2025Avalanche Canada
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Archivé · expiré 2 years ago

Danger d’avalanche

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

A combination of the lowest danger and best riding will be found in low-angled, sheltered terrain, where the snow hasn't been wind-affected.

Problèmes avalancheux

  • Wind Slabs

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

    Strong northwesterly ridgetop winds have been building wind slabs. Watch for blowing snow and avoid leeward slopes.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3

    A widespread crust with weak facets overtop is buried 40-80 cm deep. While this layer exists on all aspects, it's most likely to be triggered by a heavy load on wind-loaded slopes.

Confidence

Moderate

Avalanche Summary

Friday several wind slabs sized 1 to 2 were observed across the region.

Wednesday, a few wind slab avalanches size 1.5 to 2 were reported on east aspects in the alpine. Some were cornice-triggered, and one was noted to have stepped down the persistent weak layer. See photo below.

Natural avalanche activity has likely subsided, but we expect human-triggering to remain possible.

Snowpack Summary

Strong to extreme westerly through northwesterly winds have been scouring snow on windward faces and building thick wind slabs on lee slopes. These slabs may need a few days to bond.

Recent snowfall has been variable throughout the region; between 10 to 30 cm since the start of the week. Sunny slopes and areas below 1200 m, the snow surface may be moist, wet or crusty.

A persistent weak layer composed of facets overlying a crust is buried 40 to 80 cm deep. This layer has been stubborn to unreactive in recent snowpack tests, but may remain possible to trigger in isolated areas.

Weather Summary

Saturday Night

Mostly clear. 50 km/h west ridgetop wind. Treeline temperature -4 °C.

Sunday

Sunny. 30 to 40 km/h northwest ridgetop wind. Treeline temperature -3 °C.

Monday

Partly cloudy with 0 to 5 cm of snow. 60 to 70 km/h west ridgetop wind. Treeline temperature -1 °C.

Tuesday

Cloudy with 0 to 5 cm of snow/ light rain. 70 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1500m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Choose low-angled, sheltered terrain where new snow hasn't been wind-affected.
  • Avoid freshly wind-loaded features, especially near ridge crests, rollovers, and in steep terrain.
  • Be aware of the potential for large avalanches due to buried weak layers.
  • A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.

Régions couvertes