Boletín de aludes

South Columbia

Dec 22 – 23, 2011Avalanche Canada
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Archivado · caducó 15 years ago

Peligro de aludes

Sat
Sun
Alta montaña
3 · Notable
Límite del bosque
2 · Moderado
Bajo el límite
2 · Moderado
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Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible - Likely
    Tamaño
    1–4
    Wind slabs are sliding easily on the recently buried surface hoar. Shifting winds have set up this problem on a variety of aspects, particularly north through south east.

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible - Likely
    Tamaño
    2–4
    Right now this is more of a concern in the northwest corner of the region. As more snow falls, this problem will increase across the rest of the region. Most pronounced on sheltered, shady aspects (i.e. large, open glades facing north and east).

Confidence

Fair - Due to variable snopack conditions

Weather Forecast

Friday: Mixed skies, with southwesterly winds increasing to 30km/h through the day and highs of -6. Saturday: Continued southwesterly flow with flurries developing over the west side of the region. Freezing levels may reach 1600m. Sunday: A mix of sun and cloud, with a possibility of localized flurries. Continued southwest winds and freezing levels to 1600m.

Avalanche Summary

Avalanche observations have dramatically slowed, with minimal new observations. Reports show no new natural avalanches and small, human triggered slides. As the load increases through the weekend, the likelihood of triggering will go up. Threshold for human triggering will precede natural releases.

Snowpack Summary

A north-south split exists in this region at present as a result of the track of recent storms. Northern and western areas have seen up to 50 cm of recent storm snow, while areas further south have seen more like 20cm. This storm slab is reported to be upside-down, which means higher density snow sits on top of less dense snow. The storm slab sits above a well developed surface hoar layer from mid December, which has been reacting readily to snowpack tests and ski cutting. Additionally, remote-triggered avalanches have been reported on this layer, indicating it has a high potential for fracture propagation. All this info points to the same thing: Where the storm slab is sufficiently thick (in the order of 40 cm) and cohesive, conditions are ripe for slab avalanches. Lower in the snowpack, the mid-layers are well-consolidated and strong. Near the base of the snowpack there are a few layers that have the potential to wake up with a really big storm or very heavy loads (cornice drop). These include a surface hoar layer from early November, a crust/facet combo from October and the interface on steep glaciated terrain with snow that did not melt over the summer.

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