Avalanche Forecast

Issued: Dec 29th, 2022 4:00PM

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

Avalanche Canada jleblanc, Avalanche Canada

There is a real potential for triggering larger-than-expected avalanches as slabs are now primed to release.

Adopt a conservative approach by sticking to low-angle terrain.

Summary

Confidence

Low

Avalanche Summary

A large rider-triggered avalanche (size 2) was reported near Sun Peaks on Wednesday. The avalanche released from a persistent weak layer on a thin-thick steep roll. Although natural avalanches are tapering off, slabs should be expected to be primed for human triggering.

Please continue to share any observations or photos on the Mountain Information Network.

Snowpack Summary

Up to 25 cm of recent storm snow is now sitting on previous surfaces, varying in form from sugary faceted grains and small surface hoar crystals. Recent snow may not have bonded well to the old surface.

A buried weak layer from November lies 60 to 110 cm below the surface. Smaller avalanches may step down to this deeper layer.

The majority of the snowpack is faceted, with roughly 120 cm found at treeline and less below treeline.

Weather Summary

A weak frontal system will push over the interior Thursday after. Reinforcements will arrive later Friday as a stronger coastal system will spread snowfalls into the region. Quieter conditions are expected for the weekend.

Thursday night

Cloudy, light snow up to 2 cm, southwesterly ridge winds up to 40 km/h, treeline temperatures -6° C. Freezing level around 500 m.

Friday

Cloudy, snowfalls 5-10 cm, southwesterly ridge winds up to 50 km/h, treeline temperatures -5° C. Freezing level around 500 m.

Saturday

Mainly cloudy, isolated flurries, northwesterly ridge winds up to 30 km/h, treeline temperatures -1° C. Freezing level around 750 m.

Sunday

Cloudy, isolated flurries, northwesterly ridge winds up to 20 km/h, treeline temperatures -3° C. Freezing level around 500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Closely monitor how the new snow is bonding to the old surface.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

Storm slabs will remain reactive for longer than “typical” considering they are overlying a widespread weak layer. Additional load will keep human-triggered avalanches likely, especially where the snowpack varies from thick to thin. Watch for larger-than-expected avalanches, as slabs may step down to deeper layers and result in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Dec 30th, 2022 4:00PM

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