Bulletin d’avalanche

Kootenay Boundary

Mar 28 – 29, 2015Avalanche Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

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

Warmth is the main driver of avalanche hazard at the moment. Minimize your exposure to large slopes if the snowpack is becoming moist or wet.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–5
    Warming has added a lot of strength to the snowpack, but it may still be possible for riders to trigger a slab failing on the mid-March crust in the alpine. Moderate SW winds may increase the reactivity of this slab at upper elevations too.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    Loose wet activity is expected to persist with the bulk of the activity occurring below 2000m. Periods of sun could initiate fresh rounds of loose wet activity at upper elevations too.  Large droopy cornices are primed for failure at this time.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

Sunday: Freezing level hovering around 2000m. Light SW winds at treeline, moderate SW winds at ridgetop. Scattered cloud early in the day, likely overcast by sundown. No significant precipitation expected.Monday: Freezing level starting around 2200m, rising to 2500m by the afternoon. Very light South/Southwest winds at treeline, moderate SW winds at ridgetop. Spring pattern, intermittent cloudy periods speckled with sunny breaks. No significant precipitation expected.Tuesday: Freezing level starting around 2000m, dropping to 1500m by days end. 1 to 10mm of precipitation expected, 1 to 12cm of snow possible. Treeline winds moderate SW/W, ridgetop winds strong SW.

Avalanche Summary

A wide variety of avalanches were observed Friday: Loose wet avalanches to size 2 on all aspects between 1600m and 2200m, a size 2 wet slab on a E/SE facing feature at 2200m and even a rider triggered storm slab on an E facing feature, likely from early in the day.

Snowpack Summary

20 to 40 cm of rapidly settling wet snow can be found on the surface. Friday felt almost May-like in the mountains with temps topping out at +15c at 900m, +5c at 2200m. Temps dipped below freezing early Saturday morning for a few hours which likely created a very thin surface crust. The mid March crust/facet complex is now down 40-60cm, potentially deeper on wind loaded features. Most recent reports suggest that the overlying snow is bonding well to the crust. However, snowpack tests continue to produce sudden fracture characters indicating there is still energy at this interface.

Régions couvertes