Avalanche Forecast

Issued: Mar 14th, 2022 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Heavy snowfall, warm temperatures, and wind are expected to build reactive storm slabs which may overlie a weak layer of surface hoar, facetted snow, or a slick crust.

Choose low-consequence and well-supported terrain with no overhead hazard.

Summary

Confidence

Moderate - Forecast precipitation (either snow or rain) 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 ~1400 m, 10-20 cm of accumulation. Moderate to strong southwest winds at ridgetop. Freezing level around 1500 m.

Tuesday: Continued snowfall above ~1500 m, 5-15 cm of accumulation, rain at lower elevations. Light to moderate southwesterly winds. Freezing level around 1600 m.

Wednesday: Mix of sun and cloud with some with light precipitation, 0-5 cm of new snow accumulation above 1200 m. Light to moderate westerly winds. Freezing level around 1300 m.

Thursday: Mainly cloudy with light precipitation, 0-5 cm of new snow accumulation above 1300 m. Light to moderate westerly winds. Freezing level around 1400 m.

Avalanche Summary

Numerous natural and skier-triggered storm slab avalanches up to size 2.5 were reported over the weekend. The storm slabs were most reactive were they were sitting on a sun crust or a weak layer of surface hoar.

Riders may get surprised by widely propagating storm slabs that are sitting on a weak layer of facets/crust or surface hoar.

Snowpack Summary

20-60 cm of recent snow and moderate southwest winds have formed fresh storm slabs that are expected to be most reactive in wind-affected terrain; especially where slabs are sitting on a weak layer of surface hoar or a sun crust.

The recent new 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 late February persistent weak layer combination of crust, facets and surface hoar is down 30-40 cm. Reports suggest this layer is not a problem in most areas.

Two persistent weak layers from mid-February and late January are buried 50-120cm deep. No recent avalanches have been reported on these layers.

Terrain and Travel

  • Be especially cautious as you transition into wind affected terrain.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Use careful route-finding and stick to moderate slope angles with low consequences.
  • 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.

Problems

Storm Slabs

An icon showing Storm Slabs

20-60 cm of recent storm snow, warm temperatures, and moderate southwest winds have formed storm slabs that are expected to be most reactive in wind-affected terrain, or where slabs are sitting on a weak layer of surface hoar or a sun crust.

In steep sheltered terrain, small dry-loose sluffs may be reactive to human-triggering. Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 3

Loose Wet

An icon showing Loose Wet

Rain at lower elevations may cause wet loose avalanches to occur out of steep terrain. Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious 

Back off steep slopes as the surface becomes moist or wet.

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Likely

Expected Size

1 - 2

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