Bulletin d’avalanche

Kootenay Boundary

Apr 3 – 4, 2016Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Tue
Wed
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

The danger ratings assume around 10 cm new snow. If there is more new snow, bump up the danger ratings!

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–5
    Large fragile cornices threaten many slopes. A cornice fall could wake up a persistent weak layer and trigger a large avalanche on the slope below.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    New snow and variable winds may build new storm slabs.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    Rain on snow may lead to loose wet avalanches, especially at low elevations.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Monday

Weather Forecast

A front passing through on Monday is expected to bring around 10 mm (up to 25 mm at Kootenay Pass is possible) precipitation and moderate to strong SW winds (switching to NW post-front), with the freezing level falling from around 2500 m to 1500 m. Cloud and a few snow showers may linger on Tuesday morning, before a ridge brings dry and very warm weather again.

Avalanche Summary

A natural cycle of size 1-2 loose wet avalanches continued though the week and into Saturday. On Friday, an explosives control mission near Nelson produced several size 2-3 wet slab avalanches. Warming-related avalanche activity should ease with the passage of a cold front on Monday.

Snowpack Summary

Large cornices overhang alpine slopes and threaten to trigger avalanches on slopes below. New snow will be landing on mainly moist or crusty snow surfaces. At low elevations, the snowpack is isothermal. The late February surface hoar/ crust interface (down 80 to 130 cm) remains a low probability/ high consequence concern. Test results are variable, with occasional sudden planar (pop) results. While generally unlikely to trigger, this layer could produce surprisingly large avalanches with a cornice fall or warm temperatures.

Régions couvertes