Avalanche forecast

South Coast

Mar 17 – 18, 2021Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

A multi-day storm starts impacting the region Thursday. Rain will switch to snow and new slabs will begin to form.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2

    Snowfall is most likely at alpine and treeline elevations whereas rain may dominate for much of below treeline terrain. Wind slabs are expected to rapidly form as the snow falls with strong south wind. Use caution if you venture into lee terrain features at high elevations. In sheltered areas above the rain-snow line, there is potential for storm slabs to also build over the day, so use caution if you find around 10 cm or more of snow accumulation.

Confidence

Moderate - Uncertainty is due to the track & intensity of the incoming weather system.

Weather Forecast

WEDNESDAY NIGHT: Partly cloudy, 30 to 40 km/h south wind, treeline temperature 2 C, freezing level 1900 m.

THURSDAY: Cloudy with rain switching to snow, accumulation 10 to 20 cm, 40 to 60 km/h south wind, treeline temperature -1 C, freezing level dropping to 1200 m.

FRIDAY: Cloudy with snowfall, accumulation 20 to 40 cm, 40 to 60 km/h south wind, treeline temperature -2 C, freezing level 1000 m.

SATURDAY: Cloudy with snowfall then clearing, accumulation 5 to 10 cm, 10 to 20 km/h southwest wind, treeline temperature -1 C, freezing level 1100 m.

Avalanche Summary

We haven't received any reports of avalanche activity for the past few days. Avalanche activity is expected to quickly increase in the coming days as a multi-day storm impacts the region.

Snowpack Summary

Rain is expected to fall to the mountain tops wetting the snow surface everywhere, which will quickly switch to snow above around 1200 m on Thursday. Above the snow-rain line, wind slabs are expected to form in exposed terrain and storm slabs may form in sheltered terrain. The wind will be strong from the south, so wind slabs will dominate in leeward terrain features near ridges on northerly aspects. Expect storm slabs to be reactive once sufficient snow accumulates. Along ridgelines, cornices are large and always have the potential of failing or being triggered from the weight of a human.

Terrain and Travel

  • Wind slabs are most reactive during their formation.
  • Carefully evaluate steep lines for wind slabs.
  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
  • Extra caution is needed around cornices under the current conditions.

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