Avalanche Forecast

Issued: Dec 11th, 2023 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

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A heavy duty storm is shifting its aim towards White Pass and avalanche danger will rise as snow stacks up. Treat danger as HIGH and avoid avalanche terrain if you find more than 30 cm of new snow.

Summary

Confidence

Moderate

Avalanche Summary

Small pockets of wind slab were reported on Sunday. Take a look at this great MIN describing cross loading at Fraser Chutes.

Looking forward, steady snowfall and elevated wind are expected to create and maintain reactive avalanche conditions over the next couple of days.

Snowpack Summary

By end of day Tuesday, up to 30 cm of new snow should be added to wind affected recent snow in exposed terrain features, to existing wind slabs present in leeward features, and to 30cm of low density snow in sheltered areas.

Wind direction has been variable in the past couple days. so new snow may bury slabs that already exist on a range of aspects.

A crust can be found about 60 cm deep on terrain below 1200 m where recent snow is reportedly bonding well to it. On wind-scoured slopes it could be on the surface.

The snowpack is now above threshold for avalanches on smooth slopes at treeline with an average snowpack depth of 75 cm and counting. In wind loaded areas in the alpine the snowpack depth is approaching 2 m.

Weather Summary

Monday Night

Becoming mainly cloudy, southwest alpine wind 10-15 km/h, easing.

Tuesday

Cloudy with flurries bringing 10-30 cm of new snow, continuing overnight. South alpine wind, 40 to 70 km/h. Treeline temperature -2°C. Freezing level reaching 1200 m in the evening.

Wednesday

Cloudy with continuing flurries bringing up to 15 cm of new snow. South alpine wind 40 to 60 km/h. Treeline temperature -5°C.

Thursday

Cloudy with continuing snowfall bringing up to 20 cm of new snow and 3-day totals to 40-45 cm. Alpine wind south 50-60 km/h. Treeline temperature -2°C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Use increased caution at all elevations. Storm snow is forming touchy slabs.
  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Back off steep and aggressive lines, stick to simple terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

New snow and wind will be forming increasingly large and reactive wind slabs and storm slabs over the day Tuesday and overnight.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Dec 12th, 2023 4:00PM