Bulletin d’avalanche

North Columbia

Jan 2 – 3, 2024Avalanche Canada
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Archivé · expiré 3 years ago

Danger d’avalanche

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

Points saillants

Expect small, easily triggered avalanches on steep slopes in the Monashees, as recent snow is poorly bonded to old surfaces.

A buried weak layer may persist within range of human triggering.

Problèmes avalancheux

  • Persistent Slabs

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

    A layer of surface hoar is buried 60 to 100 cm deep. This layer may be triggerable by riders at upper elevations where it is not bridged by a thick overlying crust.

  • Storm Slabs

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

    In the Monashees, 10-20 cm of recent snow sits poorly bonded to old surfaces. Small loose dry or thin storm slab avalanches are likely triggerable by riders.

Confidence

High

Avalanche Summary

  • Small (size 1) loose dry avalanches have been easily triggered by ski cuts in the new snow on Sunday.

  • Explosive control work near Revelstoke on Saturday produced cornice and near-surface slab avalanches size 1.5-2.5.

  • A couple of natural wind slabs size 1-2 and a persistent slab size 1.5 have been reported out of steep, unsupported alpine features in the last few days.

Snowpack Summary

5-10 cm of recent snow (and up to 20 cm in the west Monashees) sits poorly bonded to old surfaces including crusts, surface hoar and facets.

The mid snowpack contains a couple of layers of note; a hard crust formed by an early December rain event around 60 cm deep and a layer of surface hoar 60 to 100 cm deep. Where it exists, the crust effectively bridges underlying weak layers, but the surface hoar remains a concern in areas that do not have the overlying crust.

The lower snowpack is variable throughout the region; in shallower snowpack areas, basal facets may exist.

Weather Summary

Monday night

Partly cloudy, ridgetop wind 20-30 km/h southeast, treeline temperature -8 °C.

Tuesday

A mix of sun and cloud, ridgetop wind 20-30 km/h southeast, treeline temperature -4 °C.

Wednesday

Mostly cloudy with a trace of new snow, ridgetop wind <20 km/h variable, treeline temperature -3 °C.

Thursday

Mostly cloudy with a trace of new snow, ridgetop wind 30-40 km/h variable, treeline temperature -2 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Closely monitor how the new snow is bonding to the old surface.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.

Régions couvertes