Bulletin d’avalanche

Kootenay Boundary

Mar 8 – 9, 2013Avalanche Canada
Voir sur la carte
Archivé · expiré 14 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
Ouvrir la carte complète

Points saillants

Problèmes avalancheux

  • 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 avalanche stepping down from the storm snow. Be aware of the sun and warmth weakening the snowpack and cornices.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–4
      Up to 30 cm of recent snow is sitting on a melt freeze crust and has formed touchy storm slabs.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–4

Confidence

Poor - Timing, track, or intensity of incoming weather is uncertain on Sunday

Weather Forecast

Friday night and Saturday:  The dominating feature is a ridge of high pressure over the whole province bringing warmer air (-1 in the alpine), freezing levels rising to 1700 m., clear skies and light NW winds. Sunday: The ridge is breaking down in the North and remains in the Southern part of the interior range. There is a chance of light precipitation for Sunday (5-10 mm) with winds picking up in the moderate range from the W. Temperatures are slightly cooler than Saturday.Monday: Another system which could deliver more precipitation is expected for Monday but the timing and intensity is still uncertain.

Avalanche Summary

Several soft slabs size 1 and 1.5 were triggered by skiers in the new snow (20-30 cm deep) and was running on the underlying crust or on the older snow interface.  There was also several reports of sluffing in steep terrain.

Snowpack Summary

Warm temperatures and solar radiation forecasted for tomorrow will weaken the surface layer possibly triggering the recent storm slab (between 20-30 cm deep). This recent snow is sitting on an older snow interface above 2000 m. and on a melt freeze crust below that elevation. In much of the region, up to 80 cm snow overlies fairly well preserved surface hoar and sun crust. This interface is still producing sudden collapse results during snow tests.  A cornice fall or an avalanche in the storm snow could definitely trigger this deeper instability, especially where the melt freeze crust does not exist above 2000 m.

Régions couvertes