Avalanche Forecast

Issued: Mar 13th, 2024 4:00PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is high. Known problems include Persistent Slabs, Loose Wet and Storm Slabs.

Avalanche Canada shorton, Avalanche Canada

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Very large avalanches will occur over the next few days.

Avoid avalanche terrain!!!

Summary

Confidence

High

Avalanche Summary

Observations from Tuesday confirm persistent slab avalanches are still a serious concern, as several size 3 natural avalanches were observed in treeline and alpine terrain in the Whistler area. There were also many size 1.5 to 2.5 storm slab avalanches over the past few days.

Looking forward we can expect warm sunny weather to cause many very large slab avalanches, as well as widespread wet loose avalanches and cornice failures.

Snowpack Summary

Rapidly rising freezing levels on Thursday will melt surfaces on all terrain except for high north-facing slopes. Over 100 cm of snow from the past week is rapidly settling, but some storm slab instabilities may still be present, especially in wind-affected areas.

A weak layer composed of facets on a crust is buried 150 to 250 cm deep and remains sensitive to both human and natural triggers. The snowpack below this interface strong and bonded.

Weather Summary

Wednesday Night

Clearing skies. 25 km/h northeast ridgetop wind. Treeline temperature -4 °C.

Thursday

Mostly sunny. 25 km/h northwest ridgetop wind. Treeline temperature +3 °C with freezing level climbing to 3000 m by midday.

Friday

Mostly sunny. 15 km/h north wind. Treeline temperature +6 °C with freezing level climbing to 3300 m.

Saturday

Sunny. 45 km/h southeast ridgetop wind. Treeline temperature +8 °C with freezing level sustained at 3300 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid avalanche terrain during periods of strong sun.
  • Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
  • Cornice failure may trigger large avalanches.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Very large persistent slab avalanches are occurring regularly in treeline and alpine terrain. The intense warming over the next few days will make these even more likely. These avalanches could run into below treeline terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

3 - 4

Loose Wet

An icon showing Loose Wet

Sudden warming will produce widespread wet loose avalanches, especially on steep sun-exposed slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2

Storm Slabs

An icon showing Storm Slabs

Warming, and/or cornice falls, could trigger slabs in the recent storm snow.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Mar 14th, 2024 4:00PM