Bulletin d’avalanche

Kootenay Boundary

Feb 4 – 5, 2015Avalanche Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

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

Avalanche danger will rise over the forecast period due loading from new snow, wind, or rain.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    3–5
    While unlikely, you may still be able to initiate an avalanche on the mid-December crust/SH interface in isolated spots where the snowpack goes from thick to thin, especially where the crust under the new snow isn't supportive.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    New snow rests on a touchy combination of crust and surface hoar. Small sensitive wind slab and fast running sluff problems are expected to transition into thick wind slab and storm slab problems with increased loading from new snow and wind.

Confidence

Good

Weather Forecast

Freezing levels are expected to climb out of valley bottoms with the onset of snowfall on Thursday and rise above 2000 m by Friday afternoon. Precipitation is expected to arrive in three separate waves of increasing intensity over the forecast period. Expect 10-20 mm falling mostly as snow (around 15 cm) by Friday morning, then another 10-20 mm turning to rain below 2000 m throughout the day on Friday, with another 15-30 mm on Saturday. Ridge top winds are expected to peak on Friday afternoon with strong southwesterlies.

Avalanche Summary

New avalanche activity includes skier and explosive controlled wind slab avalanches up to Size 2, as well as an accidentally triggered 30cm thick persistent slab avalanche that ran on the mid-December buried surface hoar.

Snowpack Summary

Light amounts of new snow adds to the 5-20 cm sitting on a widespread hard crust that is topped by large surface hoar. This combo has been reported on all aspects and elevations, but so far weak slabs have been limited to wind-loaded slopes. The mid-January weak layer of buried surface hoar is down 25-65 cm and continues to give planar results in snow profile tests. The mid-December crust/facet/surface hoar combo found down 50 - 100cm is largely unreactive.

Régions couvertes