Avalanche forecast

South Columbia

Dec 12 – 13, 2013Avalanche Canada
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Avalanche danger

Sat
Sun
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    Recent southwest winds have created fresh and reactive windslabs at higher elevations. With the current loose surface conditions there's lots of snow available for redistribution onto lee slopes.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    3–5
    A variety of persistent weaknesses exist in the mid and upper snowpack. Watch for increased reactivity with the developing snowload and forecast warming.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    In steep, wind-sheltered terrain expect the recent low density snow to sluff with the potential to run far and fast.

Snowpack Summary

Moderate to locally heavy amounts of low density snow now overlie generally faceted surfaces that formed during the recent cold snap. At the same buried interface you may find small surface hoar on sheltered slopes or windslabs in exposed terrain. On sheltered, lower elevation slopes the new snow is mostly unconsolidated; however, moderate to strong southwest winds have created wind slabs in exposed high elevation terrain.Professionals are still keeping their eye on the late-November interface (about 40-80cm below the surface) which consists of sun crusts on steep south facing slopes and surface hoar in sheltered areas. This layer is still producing sudden test results, and may be triggered with nasty consequences on steeper, unsupported terrain. At the base of the snowpack is a crust/facet combo that formed in October. About 60cm above the ground is a surface hoar layer which formed in early November. These layers have become generally inactive; however, residual risk of large, destructive avalanches exists, especially in areas with a thinner snowpack.

Confidence

Fair - Intensity of incoming weather systems is uncertain on Saturday

Weather Forecast

Friday: Light flurries / Light southwest winds / Freezing level at 1100mSaturday: Light to moderate snowfall / Strong West winds / Freezing level at 1100mSunday: Light to moderate snowfall / Moderate southwest winds / Freezing level at 1300m

Avalanche Summary

Ongoing low density surface sluffs to size 1.5 at treeline and below have been reported from the region. A few recent natural windslabs to size 2 have also been reported in north-facing alpine terrain. Recent weather has likely kept observation to a minimum. I would expect to hear more about recent avalanche activity with the forecast break in the weather on Friday.

Regions covered