Bulletin d’avalanche

South Rockies

Dec 24 – 25, 2014Avalanche Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

Fri
Sat
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré

Points saillants

Keep it conservative and give the snowpack a few days to sort itself out before thinking of venturing into more complex terrain.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    New snow and wind have formed slabs that rest on a stout crust.  In some places a very weak layer of surface hoar may rest between the crust and new snow which is a prime setup for human triggered avalanches.

Confidence

Poor - Due to the number of field observations

Weather Forecast

Synopsis: The Pacific storm cycle has come to a close, a dirty ridge builds in its wake allowing freezing levels to drop back to valley bottom. Look for cooler temps and mid-level cloud through the holiday weekend.Thursday: Freezing Level: Valley Bottom; Precipitation: Nil; Wind: Treeline: Light, Variable | Ridgetop: Moderate, WFriday: Freezing Level: Valley Bottom; Precipitation: Nil; Treeline: Light, SW | Ridgetop: Moderate, NWSaturday: Freezing Level: Valley Bottom; Precipitation: Nil; Wind: Treeline: Moderate, SW | Ridgetop: Moderate, NW

Avalanche Summary

One size 2 natural avalanche was reported on Sunday. On Monday, no natural avalanche activity was reported, but explosive avalanche control produced avalanches up to size 2.5, initiating in wind slab, then stepping down to the crust. Not much activity to report from Tuesday. If you have any avalanche observations to report, please send an email to [email protected].

Snowpack Summary

Prior to Tuesday nights 15 - 20 cm, generally light amounts of snow have fallen in the last few days. In the alpine, winds have been conducive to blowing this snow into wind slabs in exposed lee areas. 30 - 50 cm below the surface (more in wind affected areas) you are likely to find a crust that may have surface hoar on top of it. The crust is reported to extend into the alpine to at least 2100 m; the surface hoar was reported to be most reactive on shady aspects around treeline and just below, between around 1600 m and 1900 m. Where the crust exists, it is effectively bridging triggers from penetrating to deeper persistent weaknesses that formed earlier in the season. However, on high alpine slopes above where the rain crust formed, facets, and/or buried surface hoar may be susceptible to triggers.

Régions couvertes