Avalanche forecast

Sea To Sky

Feb 9 – 10, 2016Avalanche Canada
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Archived · expired 11 years ago

Avalanche danger

Thu
Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Fingers crossed for new snow on Wednesday night!

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–4
    Cornices are huge and have become weakened by recent warming and solar radiation. They can be destructive by themselves, and may also become the trigger for a large slab avalanche on the slope below. Use extra caution around ridge crests.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    Freezing levels will remain high on Wednesday and loose wet avalanches may still be triggered in steep terrain. Use extra caution if the sun makes an appearance.

Confidence

Moderate - Freezing levels are uncertain on Wednesday

Weather Forecast

On Wednesday expect mainly overcast skies. On Wednesday night and Thursday the region may see 10-15cm of moist snow with similar amounts accumulating again on Friday. On Wednesday the freezing level should drop from about 2800m to 2000m, and should remain at that elevation for the rest of the forecast period. Ridgetop winds should remain mainly moderate from the southwest.

Avalanche Summary

On Monday, warming and solar radiation triggered widespread loose wet avalanche activity in steeper, sun-exposed terrain. Large cornice collapses were also observed. Of note, warming also triggered a size 3.5 slab avalanche on the south face of Mt Currie. Similar action likely occurred on Tuesday. The gradual cooling trend will strengthen the upper snowpack making avalanches triggered by warming less likely.

Snowpack Summary

Extremely high freezing levels and solar radiation have left most surfaces moist or wet. This warming has also had a significant destabilizing effect on the snowpack. Cornices are also reported to be huge and collapse has become more likely with daytime warming. About 50-90cm below the surface, you'll likely find a rain crust which formed on January 28th. This crust is widespread and exists up to about 2050m. Where it still exists, the mid-January surface hoar layer may be found between 130 and 200 cm below the surface. The combination warm temperatures and subsequent gradual cooling is making avalanches failing on these deeper layers unlikely.

Regions covered