Avalanche Forecast

Issued: Jan 15th, 2024 4:00PM

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

Avalanche Canada LP, Avalanche Canada

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The thaw begins as temperatures warm through the week. Watch for increased wind Tuesday as it may add to the existing windslab problem or trigger small loose dry avalanches.

Summary

Confidence

Moderate

Avalanche Summary

Snow safety teams at Lake Louise and Sunshine triggered small windslabs on Monday in immediate lees with ski cuts and explosives. Several loose dry natural avalanches to size 1 were also reported.

Late last week, after the storm, there were several avalanches to size 2.5 on multiple aspects, and some are suspected of sliding on Dec 31 surface hoar, with some stepping down in the alpine to deeper layers. Most were 30-40cm deep, with some stepping down (80 cm thick).

Snowpack Summary

Mod-strong winds in the last week have formed slabs at treeline and above. 20-40 cm of recent snow over the Dec 31 layer that is comprised of surface hoar in sheltered areas and a spotty sun crust on steep solar slopes at treeline and above.

The mid-pack is supportive and contains two temperature/rain crusts from Dec 22nd and Dec 5th that reach as high as 2350 m.

The base of the snowpack consists of weak facets and depth hoar in most areas.

Treeline snow depths range from 80-120 cm.

Weather Summary

The winds have switched to a Westerly flow and the temperatures have started to warm. Expect moderate to strong W-NW winds Tuesday. Tuesday's highs will be around -15C with 2-4 cm of snow. Tuesday night into Wednesday we may see 10 cm.

For more information, click Mountain Weather Forecast.

Terrain and Travel Advice

  • Be carefull around freshly wind loaded features.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Reactive windslabs were found in immediate lees in the Sunshine and Lake Louise regions on Monday. Forecasted wind Monday night into Tuesday may contribute to the problem and may trigger a few loose dry avalanches. There is still snow available for transport from last week's storm of 10-40 cm.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The base of the snowpack consists of weak facets and depth hoar, and there has been some activity on this layer over the past week. Use caution in steep terrain or planar slopes where failures in these basal facets are more likely to propagate. Especially watch thick to thin areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Jan 16th, 2024 4:00PM