Avalanche Forecast

Issued: Apr 20th, 2023 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada mconlan, Avalanche Canada

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Assess for wind slabs in steep terrain.

Summary

Confidence

High

Avalanche Summary

A few small (size 1) wet loose avalanches were observed out of steep and rocky terrain on Wednesday. Riders also triggered some small (size 1) wind slabs on Tuesday.

Looking forward, new wind slabs could be triggered by riders in lee terrain features from Thursday night's storm. Use plenty of caution along alpine ridges, where cornices may be large.

Snowpack Summary

Around 10 cm of snow is forecast for Thursday night with southwest wind, which may form new wind slabs in lee terrain features. The snow will accumulate over a melt-freeze crust on sun-exposed slopes or 5 to 10 cm of dry snow that overlies a thick and hard crust on shaded aspects.

The remainder of the snowpack is strong with varying hard snow layers and bonded melt-freeze crusts. Cornices are large along many alpine ridges.

Weather Summary

Thursday Night

Cloudy with snowfall, accumulation 10 to 15 cm, 20 to 40 km/h southwest wind, treeline temperature -5 °C, freezing level 1000 m.

Friday

Cloudy with snowfall, accumulation 2 to 5 cm, 20 km/h southwest wind, treeline temperature -4 °C, freezing level 1300 m.

Saturday

Cloudy with trace rain or snow, 30 to 40 km/h southwest wind, treeline temperature -1 °C, freezing level rising to 1900 m.

Sunday

Cloudy with rain or snow, accumulation 5 to 10 cm, 30 to 40 km/h southwest wind, treeline temperature -2 °C, freezing level 2000 m dropping to 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Carefully evaluate steep lines for wind slabs.
  • Use ridges or ribs to avoid areas of wind loaded snow.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slabs may form from Thursday night's snow and wind. Assess for slab development before committing to large terrain features.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 21st, 2023 4:00PM