Avalanche Forecast

Issued: Mar 13th, 2024 4:00PM

The alpine rating is extreme, the treeline rating is extreme, 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 all avalanche terrain!!!

Summary

Confidence

High

Avalanche Summary

Large to very large (size 2 to 3) persistent slab avalanches are being reported across the region on a regular basis. Most have been naturally triggered, although some have been remote-triggered from 150 to 300 m away (most recently on Tuesday). There have also been reports of widespread whumpfing.

Natural storm slab avalanches (mostly size 1 to 2) were also observed during the stormy weather earlier this week.

Snowpack Summary

Rapidly rising freezing levels on Thursday will melt surfaces on all terrain except for high north-facing slopes. 40 to 80 cm of snow from the past week is rapidly settling, but some storm slab instabilities may still be present, especially in wind-affected areas. Storm snow covers a variety of layers including surface hoar in isolated shady areas.

A weak layer composed of weak faceted grains on a crust is now buried 80 to 150 cm deep. This layer remains sensitive to both human and natural triggers and continues to produce large, destructive avalanches.

The snowpack below this layer is strong and bonded.

Weather Summary

Wednesday Night

Mostly clear. 20 km/h northwest ridgetop wind. Treeline temperature -5 °C.

Thursday

Mostly sunny. 20 km/h northwest ridgetop wind. Treeline temperature +3 °C with freezing level climbing to 3000 m by midday.

Friday

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

Saturday

Sunny. 25 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 the runout zones of avalanche paths. Very large avalanches have been running full path.
  • 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

Very Likely

Expected Size

2 - 3.5

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