Bulletin d’avalanche

South Columbia

Mar 29 – 30, 2015Avalanche Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

Tue
Wed
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Areas in the south may get some sun on Monday. Direct sun may spark a new cycle of avalanche activity.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    3–6
    Large and destructive persistent slabs can be triggered by the weight of a person or sled. Stick to conservative terrain.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    New snow and winds are likely to create touchy storm slabs, especially on features in the lee of the wind.

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Snow eases to light amounts on Monday, then the next pulse begins on Monday night, bringing around 5-10 cm snow through Tuesday with moderate to strong SW winds. Freezing levels are between 1800 m and 2200 m, dropping on Tuesday to around 1600 m and 1200 m by Wednesday.  

Avalanche Summary

On Saturday, a few naturally triggered persistent slabs, size 2-3, were observed. A widespread avalanche cycle ran on Thursday and Friday in response to wet and windy conditions. These were a mix of storm slab, loose wet avalanches and persistent slabs, up to size 3.

Snowpack Summary

Strong winds have shifted recent snow onto lee slopes at high elevations. Rain on Friday soaked the upper snowpack to at least treeline. Two persistent weak layers in the upper metre or so of the snowpack are the main story. The mid-March layer, around 60 cm down, is most reactive where it exists as a crust. Around 80-100 cm down, the mid-February facet/crust interface has also been reactive with large loads like smaller avalanches stepping down, cornice fall or explosives. Both layers are sensitive to triggering and propagate easily, causing very large avalanches.

Régions couvertes