Bulletin d’avalanche

Kootenay Boundary

Dec 28, 2017Avalanche Canada
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Archivé · expiré 9 years ago

Danger d’avalanche

Fri
Sat
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Points saillants

Don't be fooled by the Moderate danger ratings. Buried weak layers still exist and may surprise in isolated terrain with nasty consequences.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2
    Continued snowfall and moderate winds are forecast to create soft yet reactive wind slabs on Wednesday night and Thursday. If the snow feels hollow or stiff, wind slabs may be larger than expected.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    A well-developed layer of surface hoar is buried up to 75cm below the surface. Use extra caution in sheltered areas at and below treeline, especially if the overlying slab is thick and cohesive.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

Wednesday night: 10-15cm of new snow / Moderate westerly winds / Alpine temperature of -13Thursday: 10-15cm of new snow / Light to moderate westerly winds / Alpine temperature of -13Friday: 5-10cm of new snow / Light and variable winds / Alpine temperature of -9Saturday: Mix of sun and cloud / Light and variable winds / Alpine temperature of -13

Avalanche Summary

On Tuesday, a skier triggered a size 1.5 wind slab on a north-facing alpine slope in Kokanee Glacier Provincial Park. The skier went for a short ride, but was uninjured in the event. No other recent avalanches have been reported. As new snow accumulates over the next few days, fresh wind slabs should remain on your radar. More importantly, the December 15th interface will become deeper. With that, the overlying slab may settle and gain cohesion increasing the likelihood of triggering of this buried persistent weak layer.

Snowpack Summary

By Thursday morning, up to 15cm of low density snow is expected to have fallen. Moderate west winds are forecast to shift these accumulations into deeper deposits in high elevation lee terrain. The new snow overlies recently buried surface hoar, although at this point not much is known about the size or distribution of this potential weak layer.Between 30 and 75cm below the surface you'll find the December 15th interface which consists of a melt-freeze crust on steep, solar, higher elevation slopes and well-developed surface hoar which seems most pronounced in sheltered treeline terrain and below. The bond at this variable interface is of critical importance, especially in areas where the overlying slab is deep and well-consolidated.The late November crust is now buried 60-100 cm and has been producing hard, resistant results in recent snowpack tests. Beneath this crust the lower snowpack is strong and well-settled.

Régions couvertes