Bulletin d’avalanche

Kananaskis

Jan 11 – 12, 2014Alberta Parks
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Archivé · expiré 13 years ago

Danger d’avalanche

Mon
Tue
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
3 · Marqué
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Points saillants

40cm of new storm snow  combined with strong SW winds and warm temps create perfect conditions to make slabs and cause poor stability.  Large avalanches involving the entire winter snowpack are occurring. Terrain recognition and avoidance are key!

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–4
    Wind slabs are now buried underneath the recent storm snow. These slabs had been settling but the new load from the recent snow may be enough to wake up these problems.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    3–6
    The new snow is adding more load to the basal facets and in some areas overloading them triggerring an avalanche that is involving the entire winters snowpack. Be conscious of large avalanches.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    2–4
    Touchy storm slabs are developing in Alpine and at treeline throughout the region. These slabs are up to 50cm thick and are reactive to light loads such as a skier.

Confidence

Fair - Due to the number of field observations on Saturday

Weather Forecast

An unstable air mass over us will continue to dominate the weather over the next few days.  On Sunday, winds and temps will decrease a little but we should still expect to see moderate SW winds throughout the day at treeline and above.  Forecasts are calling for an additional 8-10cm overnight, then dribs and drabs throughout the day on Sunday.  On Monday another pulse is expected to cross the region giving us another 10-15cm but the confidence in this system and the precip amounts are uncertain. 

Avalanche Summary

Visibility was obscured throughout most of the day on Saturday and as a result, avalanche observations were limited.  Forecasting staff were able to ski cut two sz 1.5 slabs within the storm snow on a steep N aspect at treeline.  These slabs did not step down to the weak basal layers but this was in previously skied terrain.

Snowpack Summary

Up to 40cm recent storm snow has fallen over a variety of different snow surfaces.  This snow fell under mild temperatures (-4C) and strong to extreme winds at all elevations.  As a result, new storm slabs have been quick to develop and have been rapidly overloading the weak basal facets that exist throughout the region.  Cracking along ridgelines and below ridgecrests was observed which is a good indicator of poor stability within the snowpack.  Warm temps will allow these new avalanche problems to settle out quickly but for the time being, we are in a period of poor stability.

Régions couvertes