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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Sudden warming and sun will cause a natural avalanche cycle on Thursday. Avoid avalanche terrain.

Summary

Confidence

High

Avalanche Summary

Reports of avalanche activity have been limited. A notable size 2 persistent slab avalanche was observed in Manning Park and likely occurred over the weekend (photo below).

Looking forward, warming will cause large wet loose, cornice, and slab avalanches.

Snowpack Summary

Sudden warming on Thursday will cause moist surfaces on all but the highest north-facing terrain. 30 to 50 cm of snow from the past few days is rapidly settling, but some storm slab instabilities may still be present. Storm snow sits above a thin sun crust on south aspects.

There has been evidence of two persistent weak layers roughly 80 to 120 cm deep. The upper one is a thin layer of facets and crusts or surface hoar while the deeper one is facets above a thick crust. While we have not seen many reports of persistent slab avalanches in this region, these layers should not be trusted based on notable activity in neighbouring regions.

Weather Summary

Wednesday Night

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

Thursday

Sunny. 15 km/h north ridgetop wind. Treeline temperature +4 °C with freezing level climbing to 2500 m by midday and 3000 m by the afternoon.

Friday

Sunny. 30 km/h east ridgetop wind. Treeline temperature +6 °C with freezing level climbing to 3400 m.

Saturday

Sunny. 45 km/h east ridgetop wind. Treeline temperature +8 °C with freezing level sustained at 3500 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 as temperatures increase.
  • Cornice failure may trigger large avalanches.
  • In times of uncertainty conservative terrain choices are our best defense.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Two potential weak layers are buried 80 to 140 cm deep. While we have not seen widespread evidence of this problem, it will likely become reactive with the heat and sun.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

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: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

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

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