Avalanche Forecast

Issued: Apr 20th, 2022 4:00PM

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

Avalanche Canada JSmith, Avalanche Canada

Lingering wind slabs may remain reactive to human triggers below alpine ridgetops.

 Use ridges or ribs to avoid areas of wind loaded snow. 

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

Wednesday night: Cloudy with isolated flurries (rain below around 800 m); 0-5 cm / Light southeast wind / Low of -5 / Freezing level 1100 m.

Thursday: Mostly cloudy with isolated flurries/ showers below around 1500 m; 0-3 cm / Light southwest wind / High of 3 / Freezing level 1800 m.

Friday: Mix of sun and cloud / Light northwest wind / High of 4 / Freezing level 1900 m.

Saturday: Mix of sun and cloud / Light southwest wind / High of 5 / Freezing level 1900 m.

Avalanche Summary

A small (size 1) wind slab avalanche that was remotely triggered by skiers below a ridgetop was reported on Tuesday. See MIN.

Additionally, a size 1.5 cornice failure was reported. The cornice did not trigger a slab on the slope below.

We currently have very limited avalanche observation data from this region.

Please consider posting your observations to the Mountain Information Network (MIN). Photos of current conditions and avalanches are the most helpful. 

Snowpack Summary

5-20 cm of recent snow and moderate southwest winds have formed wind slabs that may remain reactive to human triggers below alpine ridgetops.

The recent snow is sitting on a variety of hard snow surfaces, including crusts and wind scoured snow. Below this, there are several crusts in the upper snowpack, but they are unlikely to be a concern in most areas until the next significant warming event.

Terrain and Travel

  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
  • Use ridges or ribs to avoid areas of wind loaded snow.
  • Make observations and assess conditions continually as you travel.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent moderate southerly winds have formed wind slabs that may remain reactive to human triggers below alpine ridgetops.

 Use ridges or ribs to avoid areas of wind loaded snow. 

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices may be weak and reactive to human triggers. They create a significant falling hazard, and may produce large slab avalanches as they fall onto the slope below.  

Cornice failures are more likely during hot and sunny weather.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 2.5

Valid until: Apr 21st, 2022 4:00PM