Bulletin d’avalanche

Jasper

Nov 26 – 27, 2017Parks Canada
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Archivé · expiré 9 years ago

Danger d’avalanche

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

Developing windslab at Treeline and above on Saturday.  25+ cm possible with incoming storm on Sunday afternoon will increase hazard to High on Monday. 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    Be wary of areas where new snow transport has created pockets of windslab. Watch for sudden changes in texture and hardness. Typically occurring on lee aspects but may be influenced by local terrain.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    2–3
    This is a complex problem which is hard to assess and predict. Give yourself a wide margin and make conservative terrain choices.

Weather Forecast

Flurries Saturday with mod SW winds .  Alpine Temperatures up to -5.  Sunday - snow with increasing accumulation through the afternoon with 25 cm possible by early Monday morning, freezing level rising to 2200m then falling to valley bottom as storm passes.  Moderate SW winds will accompany this storm.

Snowpack Summary

Cooler temperatures have formed a surface crust from the previous moist snow below 2300m. A persistent slab between 40cm - 200cm thick sits over the Halloween Crust low in the pack. This crust can be found up to 2,700m depending on its location and is between 20cm - 40cm above the ground. Wind slabs likely exist in the upper alpine.

Avalanche Summary

No field patrol on Friday. Thursday had numerous persistent size 2.5 slab avalanches. They failed at treeline and in the lower alpine as a result of warm temperatures, rain and additional snow loading. On Nov. 22nd a field team remote triggered 3 simultaneous size 2 persistent slabs 60-150m away on either side of the wind scoop at parkers ridge.

Confidence

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

Régions couvertes