Bulletin d’avalanche

Kootenay Boundary

Mar 14 – 15, 2014Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Check out the latest Forecaster Blog for insight on the current tricky conditions.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–4
    Dynamic conditions are changing with elevation and throughout the day, due to  warming, sun-exposure, snow flurries, and wind. Old storm (persistent) slabs lurk on sheltered low-elevation slopes, while fresh slabs may form on exposed lee slopes.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–4
    Incoming storms are likely to be rain below 1800 m, further adding to the water saturation in the lower elevation snow-pack. Daytime heating and nighttime cooling are a critical part of the daily hazard evaluation.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    3–6
    Due to the high variability and significant potential consequences associated with a deeply buried facet/crust weakness, avalanche professionals have been maintaining a high level of caution and discipline.

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

Saturday: Mainly cloudy with rain showers or scattered flurries bringing 5-10 cm depending on drainage. Mostly light westerly winds with strong gusts associated with snow flurry activity. Freezing levels as high as 2000 m. Sunday: Snow with 20 cm of accumulation depending on drainage. Generally moderate but gusty westerly winds. Freezing levels dropping slightly to 1800 m. Monday: Mostly cloudy with snow flurries bringing another 5-10 cm. Generally light westerly winds gusting with flurry activity, and freezing levels down to 1600 m.

Avalanche Summary

Reports from Thursday include a remotely triggered deep persistent slab avalanche with a heavy trigger in a low angle meadow. The slab released on the facet/crust weakness down 80-100 cm on a NW aspect at 2100 m.

Snowpack Summary

Recent storm and wind slabs are bonding poorly to buried surface hoar and facets particularly on sheltered slopes such as cut blocks, and crust on previously sun-exposed slopes. Warm temperatures and sun-exposure has been making these and deeper persistent slabs very sensitive to triggers at treeline elevations and below, and resulting in surface melt-freeze cycles as high as alpine elevations. The deeper facet/crust persistent weakness buried at the beginning of February, now down 100-150 cm, has been described by avalanche professionals as "very weird". Although widespread, it has been highly variable in terms of reactivity. Convective flurry activity has already accumulated 10-15cm of fresh snow in some drainages, which has likely blown into touchy wind slabs on leeward slopes.

Régions couvertes