Avalanche Forecast

Issued: Apr 14th, 2024 4:00PM

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

Avalanche Canada trettie, Avalanche Canada

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Watch for signs of instability as you move through terrain.

A deeply buried weak layer from early April may still be rider triggerable.

Summary

Confidence

Moderate

Avalanche Summary

Many slab avalanches were observed on Thursday, the majority of these avalanches occurred in the north of the region. The avalanches were triggered naturally and by riders in alpine terrain on all aspects. The avalanches were 40 to 80 cm deep and occurred within the recent storm snow as well as on the weak layer from early April. Remotely triggered avalanches involving this layer have also been reported.

Snowpack Summary

Recent snow and westerly winds have likely formed wind slab at upper elevations. A crust exists on or near the surface on south and west facing slopes at treeline and above.

Moist snow will likely be found on all aspects and elevations except high north as the freezing level rises and the sun comes out.

50 to 100 cm of snow overlies a hard melt-freeze crust from early April. This snow is slow to bond to the crust where pockets of weak surface hoar or faceted grains rest on the crust, which is most likely on northerly aspects at treeline and alpine elevations.

Weather Summary

Sunday Night

A mix of clear skies and cloud with 5 to 15 cm of new snow. 20 to 40 km/h westerly alpine wind. Treeline temperature -6°C.

Monday

Clearing throughout the day. 10 to 30 km/h westerly alpine wind. Freezing level rising to 1100 m.

Tuesday

Sunny. 5 to 15 km/h northeast alpine wind. Freezing level rising to 1200 m.

Wednesday

Sunny. 10 to 20 km/h northeast alpine and outflow wind.  Freezing level rising to 1600 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Problems

Persistent Slabs

An icon showing Persistent Slabs

A layer of facets over a crust produced large rider and remotely triggered avalanches last week. It may still be rider triggerable.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Wind Slabs

An icon showing Wind Slabs

West winds may have formed wind slabs at higher elevations. If triggered wind slabs could step down to deeper layers.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

Wet loose avalanches are likely in steep terrain with solar input and rising freezing levels. These avalanches could step down to deeper layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Apr 15th, 2024 4:00PM

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