Avalanche Forecast

Issued: Dec 18th, 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 jpercival, Avalanche Canada

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The potential exists for recent storm snow over surface hoar to step down and trigger larger slabs in sheltered lee terrain. Select conservative terrain and assess how new snow is bonding.

Summary

Confidence

Moderate

Avalanche Summary

On Saturday a size 2.5 glide slab avalanche was observed in the alpine. Numerous both loose dry and slab avalanches up-to size 2 had been observed in steep unsupported terrain with a few of them running far in the track. All of the other professional operations in this areas did not observe any new avalanches.

On Wednesday, a large avalanche cycle occurred. Natural and explosive triggered avalanches avalanches, up to size 3, were reported throughout the region.

Snowpack Summary

In the Alpine, recently buried surface hoar is near the surface, with the latest snow redistributed into a soft slab by previous southwesterly winds. The Nov 26th layer is situated down 100 to 200 cm. Below treeline, a trace of new snow overlays small surface hoar. The mid and lower snowpack is dense and well-settled, containing various crust layers. Snowpack depths vary, averaging around 250 cm.

Weather Summary

Monday Night

Mostly cloudy, trace to 5 cm accumulation, ridgetop winds southwest 20 km/h, treeline temperature - 10°C.

Tuesday

Cloudy, 1 to 5 cm accumulation, ridgetop winds south southeast 20 km/h, treeline temperature -8 °C.

Wednesday

Mostly cloudy, 1 to 5 cm accumulation,, ridgetop winds southerly 80 km/h, treeline temperatures -6 °C.

Thursday

Cloudy, 10 to 15 cm accumulation, ridgetop winds south southeast 50 km/h, treeline temperature -2 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
  • Choose relatively conservative lines and watch for clues of instability.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Treeline avalanche sensitivity may heighten with more snow,

A persistent slab problem, 100-200 cm down on a melt-freeze crust, may be triggered by a significant load, such as a cornice failure or large explosive.

Aspects: All aspects.

Elevations: Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Wind Slabs

An icon showing Wind Slabs

Expect the sensitivity of this problem to increase with additional wind transport.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Dec 19th, 2023 4:00PM

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