Avalanche Forecast

Issued: Mar 13th, 2022 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs.

Avalanche Canada JSmith, Avalanche Canada

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Freshly formed storm slabs will likely be reactive to human triggers on Monday; especially in wind affected terrain.

Riders may be surprised by widely propagating avalanches at treeline and below where storm slabs are sitting on a weak layer of surface hoar.

Summary

Confidence

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

Weather Forecast

SUNDAY NIGHT: Snow; 5-15 cm / Moderate southwest winds / Low of -3 / Freezing level 700 m.

MONDAY: Snow (above around 1300 m); 5-10 cm, and another 5-10 cm overnight / Moderate southwest wind / High of 1 / Freezing level 1600 m.

TUESDAY: Mix of sun and cloud with isolated flurries; 3-5 cm / Light southwest wind / High of 1 / Freezing level 1500 m.

WEDNESDAY: Mix of sun and cloud with isolated flurries; 0-3 cm / Light west wind / High of -1 / Freezing level 1400 m.

Avalanche Summary

Numerous naturally triggered storm slab avalanches up to size 2 were reported at treeline and above on Saturday. They occurred primarily on wind-loaded north-east aspects.

Riders may get surprised by widely propagating storm slabs that are sitting on a weak layer of surface hoar at treeline and below.

Snowpack Summary

15-30 cm of recent snow and moderate southwest winds formed fresh storm slabs that have been most reactive in wind affected terrain; especially where slabs are sitting on a weak layer of surface hoar or a sun crust.

The 15-30 cm of recent snow is sitting on a variety of surfaces including hard wind affected snow, sun crusts on southerly slopes, and surface hoar on shady or sheltered slopes. 

The lower snowpack is generally well-settled and strong in most areas, with prominent crust layers 50 to 100 cm deep. No recent persistent slab avalanches have been reported on these layers.

Terrain and Travel

  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.

Problems

Storm Slabs

An icon showing Storm Slabs

15-30 cm of recent snow and moderate southwest winds formed fresh storm slabs that have been most reactive in wind affected terrain; especially where slabs are sitting on a weak layer of surface hoar or a sun crust.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 14th, 2022 4:00PM