Avalanche Forecast

Issued: Dec 21st, 2023 4:00PM

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

Avalanche Canada trettie, Avalanche Canada

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Approach avalanche terrain with caution, especially in areas where the presence of buried surface hoar remains a concern.

Summary

Confidence

Moderate

Avalanche Summary

Several explosive controlled storm slabs to size 2 were reported in the north of the region on Wednesday. These avalanches were on northerly aspects.

If you go out in the backcountry, please consider sharing your observations on the Mountain Information Network (MIN).

Snowpack Summary

Roughly 20 cm of new snow has accumulated over the past few days. This may have buried a layer of surface hoar in wind-sheltered terrain. A crust formed during the early December rain event exists down roughly 30 to 60 cm from the surface and is highly variable in strength, and thickness at this time.

A concerning layer of buried surface hoar is 60 to 100 cm below the surface at treeline and above.

Lower snowpack is generally facetted, with no particular layers of concern currently. The height of snow at treeline is roughly 80 to 150 cm.

Weather Summary

Thursday Night

Partially cloudy with trace amounts of new snow expected, south alpine wind 15 to 35 km/h, freezing level around 1000 m.

Friday

Partially cloudy with up to 5 cm of new snow expected, southwest alpine wind 20 to 40 km/h, freezing level around 1500 m.

Saturday

Mostly sunny with no new snow expected, west alpine wind 20 to 40 km/h, freezing level at valley bottom.

Sunday

A mix of sun and cloud with no new snow expected, south alpine wind 10 to 25 km/h, treeline temperature -6°C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Carefully evaluate steep lines for wind slabs.
  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • Uncertainty is best managed through conservative terrain choices at this time.

Problems

Persistent Slabs

An icon showing Persistent Slabs

A problematic layer of surface hoar exists down roughly 60 to 100 cm from the surface. This is currently an ideal depth for human triggering.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Wind Slabs

An icon showing Wind Slabs

As the wind picks up recent snow could be redistributed into wind slab in exposed terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Dec 22nd, 2023 4:00PM