Avalanche Forecast

Issued: Feb 23rd, 2023 4:00PM

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

Avalanche Canada isnowsell, Avalanche Canada

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Carefully assess for cohesive storm and wind slabs. Small surface avalanches remain likely to step down to deeper weak layers creating potentially large, destructive avalanches.

Summary

Confidence

Moderate

Avalanche Summary

A natural avalanche cycle occurred on Tuesday, toward the end of the stormy weather. The majority of the reported avalanches were storm slab and wind slab releases on various aspects and elevations.

Deep persistent slab avalanches continue to be periodically reported throughout the region. Including a skier-triggered, fatal avalanche last Thursday.

We are not currently expecting much natural avalanche activity. However, human-triggered slab avalanches will remain possible while the recent storm snow settles and bonds to underlying surfaces.

Snowpack Summary

Up to 50 cm of recent snow is being redistributed by northerly winds in exposed alpine terrain. While surface snow remains relatively unconsolidated in areas not exposed to recent winds. A layer of surface hoar is now buried by 30 to 50 cm in sheltered terrain and a thin sun crust on steep south-facing terrain.

In general, the mid snowpack is well consolidated and bonding.

The lower snowpack contains a number of buried weak layers with variable distribution, as well as a widespread layer of large, weak basal facets and depth hoar in places. These basal weaknesses have been responsible for a number of recent very large, destructive avalanches.

Weather Summary

Thursday night

Mostly clear / Light to moderate northeast ridgetop winds / Treeline temperatures -20 to -25 C.

Friday

Sunny / Light, northeast ridgetop wind, shifting to the southwest by end of the day / Treeline temperatures -15 to -25 C.

Saturday

A mix of sun and cloud / Moderate to strong southwest ridgetop winds / Treeline temperatures -15 to -20 C.

Sunday

Light snow, 2 to 5 cm / Moderate to strong southwest ridgetop winds / Treeline temperatures -10 to -15 C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Avoid rock outcroppings, convexities, and anywhere the snowpack is thin and/or variable.

Problems

Storm Slabs

An icon showing Storm Slabs

Recent northerly winds have created cohesive surface slabs in exposed terrain at upper elevations. While the recent snow has buried a layer of surface hoar in wind sheltered terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A very weak basal snowpack persist. Very large human triggered avalanches are possible in the alpine; especially in shallow, rocky, or thin to thick snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Feb 24th, 2023 4:00PM