Avalanche Forecast

Issued: Feb 16th, 2023 4:00PM

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

Avalanche Canada llarson, Avalanche Canada

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New snow and moderate to strong winds are building touchy wind slabs at treeline and alpine elevations. Conservative terrain travel is recommended.

Summary

Confidence

Moderate

Avalanche Summary

Natural and human-triggered size 1 to 1.5 wind slabs were reported in the Pine Pass area.

Looking forward, new wind slabs are likely to form directly lee of ridges and ribs. These new wind slabs are forming over old wind slabs that are generally bonding to previous surfaces but may be triggered by large loads like a cornice.

The lower snowpack is slowly gaining strength, continue to manage this problem by avoiding terrain that is steep, rocky, and shallow.

Snowpack Summary

Roughly 20 to 30 cm of new snow with the greatest amounts near Pine Pass is being redistributed by moderate southwest winds. New wind slabs in open terrain at all elevations will remain reactive for the near future. Cornices are becoming overhanging and reactive, and new snow and wind will further develop their growth.

The mid-pack is gaining strength and consists of rounding facets and melt-freeze crusts that are starting to degrade.

Near the base of the snowpack, a persistent weak layer composed of large and weak facets formed in November is strengthening slowly. This layer is most likely to be triggered in thin, rocky alpine and upper treeline terrain.

Weather Summary

Thursday night

Cloudy with snowfall tapering overnight, trace accumulation, 40 to 50 km/h southwest winds, treeline temperatures -12 °C.

Friday

Cloudy with flurries, increasing snowfall overnight accumulation 10 to 15 cm, 30 to 40 km/h southwest winds, treeline temperatures -10 °C.

Saturday

Cloudy with flurries easing in the afternoon, accumulation 5 to 10 cm, 30 to 40 km/h southwest winds, treeline temperatures -10 °C.

Sunday

Cloudy with snowfall, accumulations of 10 to 15 cm, southwest winds 40 to 50 km/h, treeline temperatures -10 °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.
  • Avoid exposure to slopes that have cornices overhead.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Problems

Wind Slabs

An icon showing Wind Slabs

Roughly 20 to 30 cm of new snow with moderate to strong winds have developed wind slabs in open terrain at all elevations.

Aspects: North, North East, East, South East, North West.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A layer of large, weak facets sits near the base of the snowpack. This layer is most prominent in upper treeline and lower alpine elevations. Riders are most likely to trigger an avalanche on this layer in steep, shallow terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Feb 17th, 2023 4:00PM