Avalanche Forecast

Issued: Mar 12th, 2022 4:00PM

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

Avalanche Canada JSmith, Avalanche Canada

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10-15 cm of new snow and moderate southwest winds on Friday night formed fresh wind slabs on lee features in open terrain. 

These wind slabs may be especially reactive to human triggers where they are sitting on a weak layer of surface hoar.

Summary

Confidence

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

Weather Forecast

SATURDAY NIGHT: Cloudy / Light south winds / Low of -9 / Freezing level surface.

SUNDAY: Mostly cloudy with isolated flurries; 3-5 cm, and another 5-10 cm overnight / Light southwest wind / High of -1 / Freezing level 1300 m.

MONDAY: Flurries; 5-10 cm / Strong southwest wind / High of 1 / Freezing level 1600 m.

TUESDAY: Flurries; 5-10 cm / Moderate west wind / High of 1 / Freezing level 1500 m.

Avalanche Summary

A naturally triggered size 1 wind slab on a northeast aspect in the alpine was reported on Friday.

Riders may get surprised by widely propagating wind slabs that are sitting on crusts and/or surface hoar.

Snowpack Summary

10-15 cm of new snow and moderate southwest winds on Friday night formed fresh wind slabs on lee features in open terrain.

The 15-20 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. Expect storm slabs to be most reactive where they are sitting on either a sun crust or surface hoar.

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.

Problems

Wind Slabs

An icon showing Wind Slabs

10-15 cm of new snow and moderate southwest winds on Friday night formed fresh wind slabs on lee features in open terrain. 

These wind slabs may be especially reactive to human triggers where they are sitting on a weak layer of surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 13th, 2022 4:00PM