Avalanche Forecast

Issued: Dec 11th, 2024 4:00PM

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

Avalanche Canada Parks Canada, Avalanche Canada

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Field teams over the last couple of days have noted a big difference between snowpacks west of the divide and those east of the divide. Although it is still thin at lower elevations in both areas, the snowpack is much thicker and more confidence inspiring at treeline and above if you are in a thicker, western area.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches reported by a field team in the Dolomite Shoulder area on the 93N.

Local ski hills were reporting continued explosive triggered windslabs and deep persistent slabs up to size 2 on S and N aspects although fewer results than earlier in the week.

Snowpack Summary

Windslabs exist in exposed and wind prone alpine and treeline areas. In sheltered areas, soft snow sits on a layer of facets, suncrust and isolated surface hoar. Below this, the midpack is thin and weak in eastern regions and deeper and denser in areas west of the divide. Two crust/facet layers exist near the bottom of the snowpack (Nov. 9th and Oct. 20th interfaces). Total snowpack depths at treeline are generally 60cm in eastern areas with up to 100 cm in thicker western areas

Weather Summary

Continued dry conditions for Thursday and Friday as the ridge holds. Temperatures will be in the -5 to -10 range with light westerly winds and a mix of sun and clouds. Friday night we will see an uptick in SW wind as a system approaches and light precipitation starts on Saturday.

Terrain and Travel Advice

  • Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid thin areas like rocky outcrops where you're most likely to trigger avalanches on deep weak layers.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Two weak layers near the base of the snowpack (Oct 20 and Nov 9) are producing slab avalanches down about 60-100 cm. Surface windslabs have the potential to step down to this layer. This layer has been most reactive in steep, thin, wind affected areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

JavaScript chart by amCharts 3.20.8

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Wind Slabs

An icon showing Wind Slabs

Moderate SW/W winds during the storm have created windslabs in lee features in the alpine and at treeline. These have been reactive to hand charges at local ski hills over the last few days, although natural activity has tapered.

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

Elevations: Alpine, Treeline.

JavaScript chart by amCharts 3.20.8

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 12th, 2024 4:00PM

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