Avalanche forecast

South Coast

Apr 13 – 14, 2021Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Warm temperatures and sunshine will weaken cornices and the snowpack. Avoid exposure to sun exposed slopes and cornices, especially in the afternoon. 

Check out the latest Forecaster's Blog for more information on managing these conditions.

Avalanche problems

  • Wind Slabs

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

    Isolated wind slabs may still react to human triggering in steep features at ridgecrest.

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    2–3

    Cornices are large and looming along many ridgelines. They become increasingly unstable during periods of warming.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    Surface snow will lose cohesion and become unstable with solar warming during the day. 

Confidence

Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.

Weather Forecast

A ridge of high pressure, with sunny skies and high freezing levels will dominate the weather pattern this week.

Tuesday night - Mainly clear / moderate northeast wind / alpine low temperature near 0 / freezing level 2000 m

Wednesday - Sunny / light to moderate northeast wind / alpine high temperature near 5 / freezing level 3000 m 

Thursday - Mainly sunny / moderate east wind / alpine high temperature near 5 / freezing level 3000 m 

Friday - Mainly sunny / light east wind / alpine high temperature near 5 / freezing level 3100 m 

Avalanche Summary

There have been several size 1-2 natural and human triggered storm and wind slab avalanches reported over the past few days. These were mainly on northerly aspects in the alpine and at treeline. 

Looking forward, wet loose avalanches are expected with sun and warm temperatures. The likelihood of cornice failure also increases with warming. Wind slabs may still be possible to trigger at upper elevations.

Snowpack Summary

A storm late last week brought between 30-40 cm of new snow. The snow surface is now likely a crust in most areas, except on north aspects above about 1800 m where both soft snow and wind slabs may exist. In areas where the surface is a crust, sunshine and rising freezing levels are expected to soften the crust during the day.

Cornices are large and looming along ridgelines. Their release is unpredictable, requiring a large berth if you're travelling above or below them. Forecast rising freezing levels will increase the chances of cornice releases.

Terrain and Travel

  • The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
  • Avoid exposure to sunny slopes, especially in the afternoon.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Cornices become weak with daytime heating or solar exposure.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.

Regions covered