Avalanche Forecast

Issued: Apr 22nd, 2023 4:00PM

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

Avalanche Canada jsmith, Avalanche Canada

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Cornices are currently very large and guard many ridgetops like gargoyles.

Cornice falls may trigger large avalanches on the slopes below.

Summary

Confidence

Low

Avalanche Summary

The warm temperatures and sunshine triggered numerous wet loose avalanches up to size 1.5 on all aspects/elevations on Friday. See MIN

Observations are limited at this time of year, please consider sharing any information or photos you have on the Mountain Information Network to help guide our forecasts.

Snowpack Summary

Cornices are very large and loom over slopes below like gargoyles. Cornice falls may trigger large avalanches on the slopes below.

Recent wind has varied in direction so watch for lingering wind slabs on all aspects at upper elevations.

A robust crust exists on all aspects up to approximately 1400 m and to ridgetop on sunny aspects.

A weak layer of surface hoar/crust/facets buried in early January is now around 100 cm down in most areas. A significant warming event or a large trigger (like a falling cornice) are the most likely things to activate this layer.

Weather Summary

Saturday Night

Cloudy with isolated flurries; 0-3 cm / 20 km/h southeast ridgetop wind / Temperature at treeline around -2 C / Freezing level 800 m

Sunday

Cloudy with isolated flurries; 0-10 cm / 20 km/h southeast ridgetop wind / Temperature at treeline around 2 C / Freezing level 1400 m

Monday

Mix of sun and cloud with isolated flurries; 3-5 cm / 40 km/h south ridgetop wind / Temperature at treeline around -1 C / Freezing level 900 m

Tuesday

Mix of sun and cloud / 30 km/h southwest ridgetop wind / Temperature at treeline around -2 C / Freezing level 800 m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Cornice failure may trigger large avalanches.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Carefully evaluate steep lines for wind slabs.

Problems

Cornices

An icon showing Cornices

Cornices are very large and loom over slopes below like gargoyles. Cornice falls may trigger large avalanches on the slopes below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 2.5

Wind Slabs

An icon showing Wind Slabs

Recent wind has varied in direction so watch for lingering wind slabs on all aspects at upper elevations.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 2

Valid until: Apr 23rd, 2023 4:00PM