Avalanche Forecast

Issued: Feb 1st, 2023 4:00PM

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

Avalanche Canada BW, Avalanche Canada

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The deep persistent problem remains a problem. Continue to exercise conservative terrain choices.

Summary

Confidence

Moderate

Avalanche Summary

Ski hills reported small windslabs with ski cutting and explosives on Wednesday. In the past few days, in Yoho, a deep persistent slab avalanche was observed on Mt. Carnarvon (size 3) and on Mt. Field (size 2.5). These avalanches illustrate the unpredictability of the deep persistent problem that exists in the snowpack.

Snowpack Summary

Moderate to strong west winds have formed wind effect and fresh wind-slabs at alpine and tree-line elevations. The upper snowpack has a weak interface down 20-40 cm on the Jan 4 surface hoar/suncrust layer. The Nov 16 deep persistent layer is down 40-90 cm and continues to produce variable sudden test results. The mid and lower pack is weak in eastern regions and more supportive in western areas.

Weather Summary

Cloudy skies with light flurries along the continental divide on Thursday morning will taper as a surface ridge builds bringing a clearing trend in the afternoon.

Winds will remain strong from the west with alpine temps in the -5 to -10 range on Thursday.

More details can be found in the Mountain Weather Forecast

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • In times of uncertainty conservative terrain choices are our best defense.

Problems

Wind Slabs

An icon showing Wind Slabs

Moderate to strong W winds have formed wind effect and fresh wind slabs in the alpine and treeline elevations. These wind slabs have been reactive to skier triggering.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The lower snowpack is comprised of weak facets and depth hoar with the upper snowpack forming a 40 to 90 cm thick slab above the weakness. Human triggering on this layer remains a concern.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3.5

Valid until: Feb 2nd, 2023 4:00PM

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