Avalanche forecast

Kootenay Boundary

Dec 21 – 22, 2012Avalanche Canada
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Avalanche danger

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

If more than 20cm new snow arrives with wind on Saturday, bump the danger ratings up by one at all elevations.

Avalanche problems

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–5
    Loose dry snow remains unconsolidated in terrain that is protected from the wind. There is a lot of new snow; sluffing may entrain enough snow to bury a skier/rider.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–5
    With slightly warmer temperatures, the new storm may develop a denser surface slab. Recent light snow may also be transported by forecast strong southwest winds into deep wind slabs on north through east aspects.

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Overnight Friday: 5-10 cm new snow with strong SW winds and treeline temperatures around -6C.Saturday: Snow, picking up in intensity in the afternoon. 5-10 cm. Treeline temperatures around -4C. Winds gusting to 60 km/h from the southwest.Sunday: 5-10 cm snow expected overnight Saturday, but during the day on Sunday, things should be mostly dry. Moderate SW winds. Treeline temperatures around -6C.Monday: 5 cm new snow. Moderate SE winds. Treeline temperatures falling to -10C.

Avalanche Summary

On Friday, only loose snow avalanches to size 1 were observed.On Thursday, machine-triggered avalanches were reported running at the base of the most recent storm snow down 20 to 50 cm. Explosive testing produced avalanche up to size 2.5 in the storm snow at elevations around 2000 m.On Wednesday, natural and skier-triggered avalanches up to size 2.0 were reported to be releasing down 30-50 cms in the storm snow.

Snowpack Summary

Around 110 cm new snow has fallen in the last week. The storm slab has been very easy to trigger in areas where the wind stiffened the slab a bit. In most places the slab is still relatively unconsolidated and soft and it is not propagating far. Expect heavy sluffing in steep terrain. The well settled mid-pack has not been showing shears in snow profile tests.

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