Avalanche Forecast

Issued: Dec 28th, 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

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Reactive storm slabs are the main concern.

Closely monitor how the new snow is bonding to the old surface.

Summary

Confidence

Low

Avalanche Summary

There have been no new reports lately, but it is likely that a natural avalanche cycle occurred in the last 24 hours. East of the region, there were numerous reports of natural and human-triggered avalanches. Many of these human-triggered avalanches were a surprise to the individuals triggering them. If you head into the backcountry, please consider reporting to the Mountain Information Network.

Snowpack Summary

Up to 25 cm of moist 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 if heavier loads are introduced.

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

Weather Summary

A new Pacific frontal system will push over the interior Thursday afternoon. A very gradual cooling trend begins with unsettled conditions.

Wednesday night

Mostly cloudy, light snow 2-4 cm, southwesterly ridge winds up to 40 km/h, treeline temperatures -8° C. Freezing level at valley bottom.

Thursday

Increasing cloudiness, southerly ridge winds up to 40 km/h, treeline temperatures -6° C. Freezing level around 500 m.

Friday

Cloudy, light snow 2-4 cm, southerly ridge winds up to 40 km/h, treeline temperatures -5° C. Freezing level around 500 m.

Saturday

Mainly cloudy, isolated flurries, westerly ridge winds up to 25 km/h, treeline temperatures -5° C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • 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 slab formation was prone due to recent warm temperatures and precipitation. At higher elevations, greater accumulations may be found, and fresh wind slabs have likely developed. If triggered, storm slabs may step down to deeper layers and result in large avalanches.

Assess conditions as you travel and watch for signs of instability like whumpfing, shooting cracks or recent avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Dec 29th, 2022 4:00PM

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