Avalanche Forecast

Issued: Nov 26th, 2021 3:00PM

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 TRettie, Avalanche Canada

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Pay attention to how the wind has redistributed recent snow as you gain elevation. Snow fall varies throughout the region.

Summary

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

Friday night: A break in the storms will arrive over the Purcells. Freezing levels will fall to valley bottom. Winds will be moderate from the West.

Saturday: Cold and Dry conditions across the Purcells in the morning. A split in the weather will happen in the evening with the North half of the range seeing less snow, freezing levels at valley bottom and light to moderate Southwest winds. Meanwhile the Southern half will see freezing levels rise to 1500m with moderate to strong winds in the alpine. 10 to 20cm of new snow.

Sunday: The storm will be most intense South of the Bugaboos where the freezing level will hit 2000m and 30cm of new snow will fall with strong South west winds. The Dogtooth will see up to 20cm with moderate to strong Southwest winds and freezing levels rising to 1500m.

Monday: weather will clear throughout the day and winds will move to light to Moderate from the West. Freezing levels in the North will fall to valley bottom, Freezing levels will fall to 1500m in the South.

Avalanche Summary

Several size 1 natural avalanches were observed in the Dogtooth range.

Snowpack Summary

New wind slabs have formed in exposed treeline and alpine features. A mid November rain crust is down 30 to 60cm and exists below 2100m.

Several early season crusts exist throughout the lower pack. A late October facet/crust layer sits at the bottom of the snowpack. it likely only exists above 1900m.

 snowpack height at treeline is around 50 to 140cm.

Terrain and Travel

  • Be alert to conditions that change with elevation and wind exposure.
  • Avoid areas where the snow feels stiff and/or slabby.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Use caution on large alpine slopes, especially around thin areas that may propagate to deeper instabilities.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind is redistributing new and loose snow, building slabs around ridgeline and lee features. Be especially wary around wind-loaded slopes in the alpine, triggering a wind slab avalanche here could step down to ground.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Weak snow at the base of the snowpack has produced a few recent avalanches. We need more information on the distribution of this layer but we suspect it only exists at high treeline elevations and into the alpine.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

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