Avalanche Forecast

Issued: Mar 14th, 2022 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Recently formed storm slabs are expected to remain reactive to human-triggering where they overlie a weak layer of surface hoar or a crust. 

Expected to find deeper and more reactive slabs in wind-loaded terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

A series of frontal systems impacting the coast will bring continued snowfall throughout the week.

Monday Overnight: Overcast to obscured skies, with rain at lower elevations and snowfall above ~1500 m, trace to 10 cm of accumulation. Moderate to strong southwest winds. Freezing level around 1600 m.

Tuesday: Continued snowfall above ~1400 m, 1-10 cm of accumulation, rain at lower elevations. Light to moderate southwesterly winds. Freezing level around 1500 m.

Wednesday: Mix of sun and cloud with light flurries. Light to moderate westerly winds. Freezing level around 1500 m.

Thursday: Mainly cloudy with light precipitation, 1-5 cm of new snow accumulation above 1300 m. Light to moderate westerly winds. Freezing level around 1400 m.

Avalanche Summary

Numerous naturally triggered storm slab avalanches up to size 2 were reported at treeline and above over the weekend. 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

15-40 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 recent storm snow is sitting on various 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

15-40 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 - 2.5

Valid until: Mar 15th, 2022 4:00PM