Avalanche Forecast

Issued: Feb 16th, 2020 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.

Parks Canada deryl kelly, Parks Canada

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Jasper.

Stale weather to remain through Monday. Forecasts then show a slow increase in temperatures and, sunny skies.

The late winter sun is starting to penetrate the snowpack. Expect some localized instability on steep, solar aspects in the afternoon.

Summary

Weather Forecast

Zonal flow from west to east cycling through the region. A shallow trough holding the last of the moisture moving through, before flow shifts from the Northwest with the approaching ridge on the pacific. Clearing and slight warming by Tuesday/Wednesday.

Find the Alberta Rockies weather synopsis here: Avalanche Canada Mountain Weather Forecast

Snowpack Summary

Variable strength windslab on the surface. Pronounced cornice development on northerly aspects and cross loaded features treeline and above. A supportive mid-pack is bridging the deeper basal facets and depth hoar in some locations.

Average HS at treeline: ~180cm.

Avalanche Summary

Previous public MIN (Mountain Information Network) report of natural size 2, southwest aspect at treeline in the Maligne Valley (thanks @Kaylaolde!!). Field team in Whistler/Portal Creek observed no recent natural avalanche activity; ski-pen 10-15cm.

This area is now open after a seasonal delayed access restriction to protect the Woodland Caribou.

Confidence

Intensity of incoming weather systems is uncertain on Tuesday

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs are very prevalent with previous loading in lee features. Sensitivity will vary with local loading and wind patterns.

  • Watch for pockets of hard windslab in steep alpine terrain features..
  • Assess start zones carefully and use safe travel techniques.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Shallow snowpack areas and/or large triggers such as cornice failures could trigger this deep layer. The consequences would be severe!

  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely

Expected Size

1.5 - 3

Valid until: Feb 17th, 2020 4:00PM

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