Bulletin d’avalanche

Kananaskis

Mar 17 – 18, 2013Alberta Parks
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Archivé · expiré 14 years ago

Danger d’avalanche

Tue
Wed
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Up to 40cm of recent snow at treeline and above.  Winds have been variable so storm slabs are being found on all aspects.  Winds will increase. Westerly winds will become strong on Monday so watch for these new slabs to become more reactive.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    A rain crust is found on all aspects up to 22-2400m.  The bond with this new snow and the underlying crust is variable.  Be sure to dig down and inspect this layer as you travel.  Convex slopes at treeline and gullies are suspect.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–4
    Up to 80cm of recent snow is overlying the 0303 temperature crust that is being found on solar aspects well into the alpine.  Field tests are showing the bond of the new snow to this crust as good but warm temperatures may wake up this layer.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–4
    New touchy storm slabs up to 30cm thick have developed in Alpine terrain.  These same slabs are being found at treeline in open areas such as ridgelines and in gullied terrain.  As winds increase, these slabs will become more reactive.

Confidence

Good

Weather Forecast

An additional 5cm of new snow will likely fall before Monday morning as the cold air continues to push into the forecast area.  Winds on Monday are expected to increase into the moderate range at higher elevations out of the NW and temperatures are forecast to cool down into the -18C range in the Alpine.  Freezing levels will remain at the valley bottoms.  Winds will be a key factor to pay close attention to as lots of recent storm snow is now available for transport.

Avalanche Summary

A few sz 2 natural avalanches were observed on solar aspects at treeline and above over the past 24hrs.  These slides appear to have failed on the 0312crust.  Also, lots of loose dry slides were observed in steep alpine terrain on all aspects.

Snowpack Summary

Up to 35cm HN24 at treeline tapering down to 20cm at valley floors.  This snow was rapidly settling at lower elevations due to the warm temps.  Variable light (gusty to moderate) winds were creating pockets of touchy storm slabs along ridgelines lines at treeline and in open features in Alpine terrain.  There was also reverse loading on-going at higher elevations due to the NW winds.  The 0312 crust was found down 85cm on a south aspect at treeline and the 0303 crust was found down 110cm (Photo).  Easy shears can be found in the upper snowpack within the storm snow and moderate to hard sheers persist down 85 on the 0312 crust.  The 0312 crust is supportive at lower elevations which makes travel easy.  Beneath this crust the snow is moist.

Régions couvertes