Bulletin d’avalanche

Kananaskis

Mar 19 – 20, 2016Alberta Parks
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Archivé · expiré 11 years ago

Danger d’avalanche

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

Quality of overnight freeze will play a strong factor in stability during the day on Sunday (see weather forecast tab for additiona details).  Freezing level was close to 2400m on Saturday and forecast to be higher on Sunday.

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    3–6
    Pretty much every cornice that has collapsed has triggered a large avalanche on the underlying slopes.  Avoid travel underneath cornices at this time.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–5
    Wind slabs up to 40cm thick are present in lee and cross-loaded features in alpine areas and in very specific locations at treeline.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    3–6
    Thin snowpack areas are places where you may be able to awaken the deeper basal instabilities.  Choose routes that avoid these areas especially in steeper snowpack areas.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Sunday

Weather Forecast

Forecasts for the next 24hrs are calling for cloud to move in overnight, and a mix of sun and cloud throughout the day tomorrow.  Cloud cover overnight on Saturday will be a key thing to note with regards to stability on Sunday.  If clouds move in, it is unlikely that the snowpack will get any re-freeze overnight and stability will deteriorate earlier in the day on Sunday.  If there are no clouds, the snowpack should get a good freeze overnight and stability will deteriorate as the sun comes out and temperatures warm up throughout the day much like it did on saturday.  So, pay attention to the quality of the freeze overnight and cloud cover.

Avalanche Summary

Numerous loose wet avalanches up to sz 1 were observed.  Field teams were down from the Spray area early in the day but we suspect that there were some solar triggered avalanches initiated later in the day.

Snowpack Summary

Strong solar radiation influence throughout the region today with temperatures at 2200m  of 5C.  Moist surface snow was being encountered up to ridgelines and loose wet avalanches were being observed from steeper terrain into the Alpine.  Northern aspects remained dry with isolated windslabs along ridgelines and in gullies features up to 40cm thick.  Field tests on Friday were showing that these slabs were failing in the moderate range with not to much propagation.  Cornices are still large and failures of these features is still common.  So far, pretty much every cornice failure has triggerred a substantial avalanche on the underlying slopes that failed either at or near ground.

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