Avalanche Forecast

Issued: Dec 25th, 2023 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Avoid wind-loaded areas and keep in mind that a weak layer of surface hoar is still buried within the range for large human-triggered avalanches.

Summary

Confidence

Moderate

Avalanche Summary

A natural avalanche cycle occurred on Friday evening. Numerous large (size 2 to 3) storm and wind slabs were reported from the alpine and treeline on a variety of aspects.

Reactivity persisted into the weekend, with numerous skier-triggered wind slabs up to size 2 reported in the alpine and treeline. Check out this MIN for an example. A notable skier-triggered size 2 persistent slab occurred in the Selkirks east of Revelstoke on a northeast aspect in the alpine on Saturday.

Snowpack Summary

Recent storm snow has been redistributed into wind slab near ridge crests by strong winds. Below treeline a new crust is on or near the surface.

The mid pack contains several layers of note; a layer of surface hoar and a crust down 20 to 50 cm, a significant crust from the early December rain event down around 60 cm and a layer of surface hoar down 60 to 100 cm.

The make up of the lower snowpack is variable throughout the region, in shallower snowpack areas, basal facets may exist

Weather Summary

Monday Night

Increasing cloud cover with isolated flurries. Alpine wind southwest 30 to 60 km/h. Treeline temperature -4 °C.

Tuesday

Cloudy with snowfall, up to 5 cm of accumulation. Alpine wind southwest 30 to 60 km/h. Treeline temperature -4 °C. Freezing level rising to 800 m.

Wednesday

A mix of sun and cloud with isolated flurries. Alpine wind southeast 30 to 70 km/h. Treeline temperature -4 °C.

Thursday

Cloudy with snowfall, up to 5 cm of accumulation. Alpine wind south 30 to 60 km/h. Treeline temperature -3 °C. Freezing level rising to 1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Wind slabs are most reactive during their formation.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.

Problems

Wind Slabs

An icon showing Wind Slabs

Fresh, reactive wind slabs may form throughout the day in lee features at treeline and above.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A layer of surface hoar is down 60 to 100 cm in the snowpack. This layer is still concerning where a thick crust is not found above it.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Dec 26th, 2023 4:00PM

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