Avalanche Forecast

Issued: Jan 19th, 2024 4:00PM

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

Avalanche Canada dnylen, Avalanche Canada

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Recent natural slab avalanches warrants conservative terrain choices.

Be aware of changes underfoot (transitions into wind stiffened snow) and overhead (ridge wind, and large slopes).

Summary

Confidence

Moderate

Avalanche Summary

Large natural wind slabs, up to size 3, were still being reported on Thursday. Earlier in the storm on Wednesday, two persistent slab avalanches (size 1 and 2) were remotely triggered by skiers in the Northern Selkirks. These avalanches occurred on north aspects at treeline. Several natural and skier-triggered storm slabs were reported from alpine and treeline terrain up to size 2.

Snowpack Summary

20 to 30 cm of low-density storm snow is being variably altered by wind and has buried a variety of old snow surfaces. It sits above unconsolidated faceted snow, surface hoar and firm wind-pressed snow in open terrain at treeline and above.

Down 50 to 70 cm a crust, facet, and/or surface hoar layer exists. This may become a problem once the snow above starts to stiffen and form a slab.

130+ cm down another surface hoar layer exists that was buried in early December. This seems to be of most concern above 2000 m where a robust crust doesn't exist above it, or in shallow snowpack areas.

The depth of the snowpack varies greatly throughout the region and weak basal facets are present at the base of the snowpack.

Weather Summary

Friday Night

Cloudy with up to 10 cm of snow. Alpine wind south 10 to 60 km/h. Treeline temperature rising to -13 °C.

Saturday

Cloudy with up to 10 cm of snow. Alpine wind southwest 10 to 50 km/h. Treeline temperature rising to -8 C.

Sunday

Cloudy with up to 5 cm of snow. Alpine wind southwest 10 to 30 km/h. Treeline temperature rising to -5 C.

Monday

Cloudy with up to 5 cm of snow. Alpine wind south 10 to 30 km/h . Treeline temperature around -4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slabs will take time settle. Since natural avalanches are still happening be mindful of what is above you.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Two weak layers of surface hoar exists deeper in the snowpack. They have recently been reactive and triggered by people. As the unconsolidated snow settles and forms a slab, a reactive upper snowpack may exist.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Basal facets remain a concern in steep, rocky alpine features with thin-to-thick snowpack transitions.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Jan 20th, 2024 4:00PM

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