Avalanche forecast

South Columbia

Nov 30 – Dec 1, 2013Avalanche Canada
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Avalanche danger

Mon
Tue
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Snowfall amounts are uncertain for Sunday. If the new snow amounts are upwards of 20cm in your area actual danger ratings may be HIGH

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    3–5
    A few persistent weak layers exist in the mid and lower snowpack. The weight of the new snow forecast for the weekend could act as the tipping point for these layers, producing large and destructive avalanches.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    The new storm slab may be especially touchy in wind affected terrain, or in areas where it overlies recently buried weak layers.

Confidence

Fair - Forecast snowfall amounts are uncertain on Sunday

Weather Forecast

Sunday: Moderate to locally heavy snowfall / Strong southwest winds / Freezing level at about 1000mMonday: Light snowfall / Light west winds / Freezing level at valley bottomTuesday: Clear skies / Light north winds / Alpine temperatures of about -17.0

Avalanche Summary

No reports of recent avalanche activity have been received. I would expect a new round of storm slab activity with weather forecast for the weekend.

Snowpack Summary

Total snowpack depths range from 110 to 160cm at treeline across the region. On the surface a developing storm slab covers a variety of old surfaces which include: old wind slabs at higher elevations, melt-freeze crusts on previously sun-exposed slopes and surface hoar in sheltered terrain.In the mid snowpack you may find a layer of surface hoar buried in mid-November ranging from 60cm-100cm in depth. An October crust/facet combo exists near the base of the snowpack. The most likely place you'd trigger this layer is on smooth, planar, high north facing slopes, especially if the snowpack is unusually shallow in that area.These persistent layers are slowly becoming more difficult to trigger. However, they have the potential to cause large and destructive avalanches, and may 'wake-up' with the increased load of new snow forecast for the next few days.

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