Avalanche Forecast

Issued: Dec 29th, 2022 4:00PM

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

Avalanche Canada isnowsell, Avalanche Canada

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As snow quality increases and freezing levels drop be mindful that weak layers persist deep in the snowpack. Small avalanches on the surface have the potential to step down to deeper layers resulting in large, destructive avalanches.

Summary

Confidence

Moderate

Avalanche Summary

Several small, size 1 to 1.5 avalanches were reported on Wednesday. They were a mix of controlled and accidental avalanches, failing in the new storm snow.

One explosive-triggered, large, size 2.5 avalanche was reported at a treeline elevation. It failed on a crust buried on Dec 26.

Please continue to post your observations and photos to the Mountain Information Network.

Snowpack Summary

20 to 60 cm of recent snow, is being redistributed by southerly winds and overlies a crust. Below the crust, the upper snowpack is generally saturated from the rain events over Christmas.

A number of layers persist deeper in the snowpack, consisting of weak facet and surface hoar crystals, along with several crusts.

Below treeline, a saturated snowpack is refreezing. Total snow depths are roughly 90-140 cm at treeline and up to 200 cm in the alpine.

Weather Summary

Thursday night

Cloudy and light snow, 2 to 5 cm. Light to moderate south winds. -5 C at treeline. Freezing levels 700 m.

Friday

Cloudy and snow, 10 to 20 cm. Moderate southerly winds. -5 C at treeline. Freezing levels 1000m.

Saturday

Cloudy and snow, 5 to 10 cm. Light to moderate southwest winds. -5 to -10 at treeline. Freezing levels 1000 m.

Sunday

Cloudy with periods of sun. No precipitation. Light southwest winds. -10 C at treeline. Freezing levels 700 m.

Saturday

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for changing conditions today, storm slabs may become increasingly reactive.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

20 to 60 cm of recent snow overlies a melt freeze crust, produced during the warm weather over Christmas. Be especially cautious transitioning into wind-loaded terrain, where storm slabs are deep and may be more reactive to human-triggering.

If triggered storm slabs may step down to deeper layers resulting in very large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

A crust with weak, facetted snow above and below is buried by anywhere from 50 to 200 cm of snow.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

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

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