Avalanche Forecast

Issued: Nov 24th, 2023 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Limited observations and the potential for large human-triggered avalanches necessitate a conservative start to the season.

Summary

Confidence

Low

Avalanche Summary

During the storm last week, numerous natural wind slab and persistent slab avalanches were reported up to size 3 in Ningunsaw and Bear Pass.

Natural avalanche activity tapered with the storm. No new avalanches have been reported in the past few days.

Observations are very limited at this time of year. If you do head out, do so with a cautious and investigative mindset, and consider submitting a MIN report.

Snowpack Summary

40-70 cm of recent storm snow has been redistributed into wind slabs in the alpine and treeline. Surface conditions otherwise have been reported as 10-15 cm of dry snow overlying a series of crusts or moist snow.

Observations are limited, but a problematic crust/facet combination exists near the base of the snowpack in the Bear Pass and Ningunsaw area (likely elsewhere too). With total snowpack depths around 150 cm at 1000m, this layer is a concern for human triggering, particularly in shallow or variable depth snowpack areas in the alpine.

Weather Summary

Friday night

Cloudy with light rain, northwest alpine wind 30 to 60 km/h, treeline temperature 0°C.

Saturday

Mostly cloudy with a chance of light rain, northwest alpine wind 15 to 35 km/h, treeline temperature 0°C, freezing level 1100 m.

Sunday

Mostly cloudy with light flurries, southwest alpine wind 30 to 60 km/h, treeline temperature -2°C.

Monday

Cloudy with 1-5 cm of snow, southwest alpine wind 40 to 70 km/h, treeline temperature -2°C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Make observations and assess conditions continually as you travel.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Avoid areas where the snow feels stiff and/or slabby.

Problems

Wind Slabs

An icon showing Wind Slabs

Northwest wind accompanying last week's storm have formed wind slabs in the alpine and treeline.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

A weak layer of sugary facets overlying a crust have been reported near the base of the snowpack. Observations of this layer have been limited, but it is most likely to be problematic in steep, wind-loaded alpine terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Nov 25th, 2023 4:00PM

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