Avalanche Forecast

Issued: Apr 21st, 2024 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

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Watch for wind loaded pockets in leeward features at upper elevations.

Expect loose avalanches when the sun hits fresh snow in steep terrain.

Summary

Confidence

Moderate

Avalanche Summary

A small handful of avalanches were reported in the alpine late last week, including:

  • a remotely skier-triggered size 2 failing on moist snow below the crust, in which another skier was caught but did not sustain any injury

  • a skier-controlled size 1 wind slab below an convex roll

  • a natural size 2 storm slab on a steep, west-facing moraine feature

  • a cornice failure did not propagate any weak layers on the slope below

Snowpack Summary

Up to 20 cm of new snow sits over a widespread melt-freeze crust on all but high north-facing alpine terrain, where snow is dry and wind affected.

Weather Summary

Sunday night

Up to 5 cm of new snow at upper elevations. 30 to 50 km/h northwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1200 m.

Monday

A mix of sun and cloud. <20 km/h northwest ridgetop wind. Treeline temperature -1 °C. Freezing level 2000m.

Tuesday

A mix of sun and cloud. 10 to 30 km/h southwest ridgetop wind. Treeline temperature +3 °C. Freezing level 2300m.

Wednesday

Sunny. 10 to 30 km/h southwest ridgetop wind. Treeline temperature +4 °C. Freezing level 2400m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Brief periods of sun could quickly initiate natural avalanche activity.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent snow and wind have formed fresh wind slabs in lee terrain features at upper elevations. Wind slabs may be especially reactive where they sit over a crust.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Loose Dry

An icon showing Loose Dry

New snow will be especially sensitive to seeing the sun for the first time.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 1.5

Valid until: Apr 22nd, 2024 4:00PM