Bulletin d’avalanche

Kootenay Boundary

Mar 10 – 11, 2013Avalanche Canada
Voir sur la carte
Archivé · expiré 14 years ago

Danger d’avalanche

Tue
Wed
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
Ouvrir la carte complète

Points saillants

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–5
    Wind slabs have formed recently and are prone to skier triggering especially where they sit on the buried melt-freeze crust below 2000 m.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–6
    The 80 cm deep surface hoar/sun crust weak layer could be triggered by a cornice fall or an slab avalanche stepping down.

Confidence

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

Weather Forecast

Sunday night and Monday: A quasi-pineapple express is setting over the region that could last till Wednesday. On and off precipitation should start Monday with light to moderate NW winds. Temperatures are forecasted to start to warm up in the alpine (-3 C) and freezing levels to rise to 1300 m.Tuesday: Moderate to heavy precipitation are expected for the region with moderate to strong winds from the SW. Freezing levels rising to 2000 m.Wednesday:  Another frontal system is moving across the region which could give more moderate precipitation and slightly similar mild temperatures but with lighter winds from the same direction.

Avalanche Summary

Widespread natural and skier triggered moist loose avalanche activity on solar aspect up to size 2. There was also report of sluffing on steep northerly aspect.

Snowpack Summary

Recent windslabs have formed on lee features with W and E winds in the alpine and below ridgetops at treeline. These will still be susceptible to sledder and skier triggering. Outside of wind effected areas, I suspect that the top snowpack is generally gaining strength and starting to bond to the underlying surfaces. The 25-30 cm of snow from earlier this week is sitting on an older snow interface above 2000 m. and on a melt freeze crust below that elevation. Up to 80 cm snow overlies a surface hoar and sun crust which is becoming less reactive to skier traffic but that is still a concern to professionals. At the surface, there is a suncrust on SE-S-SW facing slopes all the way up in the alpine, a melt-freeze crust up to 1800 m. and some surface hoar on shaded slopes above that elevation.

Régions couvertes