Avalanche Forecast

Issued: Apr 20th, 2023 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs.

Avalanche Canada mconlan, Avalanche Canada

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Stormy conditions on Thursday night will increase avalanche danger for Friday. Travel conservatively and give the snowpack a bit of time to settle.

Summary

Confidence

High

Avalanche Summary

Storm snow from earlier this week was reactive to human traffic (e.g., as seen here during Tuesday's storm). We expect that similar avalanches could be triggered by riders on Friday within the latest storm snow from Thursday night. Best to give the snowpack a bit of time to settle and bond before committing to consequential terrain.

Avoiding cornice exposure is also a good idea, as they are very large and looming at this time of year.

Snowpack Summary

20 to 30 cm of storm snow is forecast to accumulate by Friday morning, forming new storm slabs. This adds to the 100 cm of snow that accumulated since the weekend. The snow is forecast to fall with strong southerly wind, meaning deeper and touchier deposits may be found in lee terrain features in wind-exposed terrain.

The remainder of the snowpack is strong and well-bonded.

Cornices are large and looming at this time of year.

Weather Summary

Thursday Night

Cloudy with snowfall, accumulation 20 cm, 30 to 60 km/h south wind, treeline temperature -3 °C, freezing level 1000 m.

Friday

Cloudy with light snowfall, accumulation 2 to 5 cm, 10 km/h south wind, treeline temperature -1 °C, freezing level 1200 m.

Saturday

Cloudy with light snow or rain, accumulation 1 to 3 cm, 10 to 30 km/h south wind, treeline temperature 0 °C, freezing level 1100 m rising to 1900 m.

Sunday

Cloudy with rain or snow, accumulation 20 cm above the rain-snow line, 20 to 40 km/h southwest wind, treeline temperature 3 °C, freezing level 1900 m dropping to 1200 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Keep your guard up at lower elevations. Storms slabs have been reactive at all elevations.
  • Choose relatively conservative lines and watch for clues of instability.
  • Avoid terrain traps where the consequence of any avalanche could be serious.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Storm Slabs

An icon showing Storm Slabs

Another 20 to 30 cm of snow is forecast for Thursday night, forming new storm slabs. Use caution entering steep terrain features and assess for signs of instability. Slabs may be deeper and toucher on northerly terrain features at high elevations in wind-exposed terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

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