Avalanche Forecast

Issued: Nov 26th, 2021 3:00PM

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

Avalanche Canada TRettie, Avalanche Canada

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the presence of wind slab is driving the hazard rating. be very cautious when exposing your group to wind effected terrain in the treeline and alpine.

Summary

Confidence

Moderate - Uncertainty is due to the extreme variability of wind effect on the snowpack.

Weather Forecast

Friday night: Freezing levels will fall to valley bottom or near valley bottom. We will see a clearing trend with no new snow and light to moderate Southwest winds.

Saturday: dry conditions in the morning. another storm will hit the North Columbias on Saturday afternoon with the largest snowfall taking place in the evening. Freezing levels will rise to 1200m and winds will return to moderate to strong from the Southwest.

Sunday: The storm will reach its peak early in the morning. Freezing levels will rise to 1800m and stay elevated for the day. Up to 50cm of new snow will be accompanied by strong Southwest winds.

Monday: Milder weather will come to the North Columbias. Freezing levels will fall to 800m with moderate West alpine winds. Some light flurries are possible.

Avalanche Summary

On Thursday the North Columbias experienced a natural avalanche cycle to size 3. Avalanches were observed on all aspects in the treeline and alpine, some running nearly full path.

Snowpack Summary

Wind slabs can be found in exposed alpine and treeline features. 30 to 70cm overlies a mid November rain crust which exists below 1900m. Snowpack depth tapers off quickly below 1700m.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

Rider triggerable wind slabs can be found on exposed features in the treeline and alpine.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Nov 27th, 2021 3:00PM