Avalanche forecast

South Columbia

Nov 27, 2016Avalanche Canada
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Avalanche danger

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

New snow has increased avalanche danger in the South Columbia mountains. Make conservative terrain choices until conditions improve.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    2–3
    A heavy snowfall on Saturday has increased the size and likelihood of triggering storm slab avalanches, especially in exposed lee terrain. This increased load has the potential to trigger deeper instabilities.

Confidence

Moderate -

Weather Forecast

Moderate to strong southerly winds will continue on Saturday evening before easing overnight. Sunday will see continued light snowfall and light winds shifting from southwesterly to westerly. Temperatures will begin to cool on Sunday and into early next week. No snow is expected for Monday and Tuesday as cloud cover decreases and winds shift to the northwest.

Avalanche Summary

Although stormy weather allowed only limited observations, skier triggered size 1 and natural size 2+ avalanches were reported in Rogers Pass on Saturday. Explosives control in the Revelstoke area on Friday also yielded numerous size 2 results with slab thickness reaching up to 80cm in depth. Storm slab avalanche activity is expected to continue with ongoing wind redistribution.

Snowpack Summary

Up to 25 cm of new snow fell on Saturday under moderate to strong southerly winds. This new snow now covers the already touchy wind slabs that existed in exposed areas at treeline and above. Several interface layers exist within the snow above the November 13 crust, most notably a sun/temperature crust which formed on steep solar aspects on November 22. The November 13 crust now lies up to a metre below the surface. Below this crust the mid and lower snowpack are well consolidated, with moist snow present at treeline and below.

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