Avalanche Forecast

Issued: Dec 27th, 2020 5:10PM

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

timothy Johnson,

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Conservative terrain choice is key until the reactivity of avalanche problems and their location can be deduced.

Summary

Weather Forecast

Monday: Cloudy with sunny periods. Precipitation: Nil. Alpine temperature: High -10 C. Ridge wind west: 10 km/h.

Tuesday: A mix of sun and cloud. Precipitation: Nil. Alpine temperature: Low -16 C, High -7 C. Ridge wind west: 10-20 km/h.

Snowpack Summary

15-30cm of soft snow or dense wind-slabs location dependent over a generally firm mid-pack. Dec. Surface Hoar is down 40cm in isolated sheltered spots and reactive to skier traffic. An early season crust is down 40-100cm and decomposing. It overlies basal facets and depth hoar but is well bridged by the mid-pack above unless shallow location.

Avalanche Summary

Sz 2 wind slab at 2000m on a NE aspect running far near the Saskatchewan Crossing yesterday. Surface hoar reactive to skier loads in isolated sheltered location up to 2000m.

Confidence

Due to the number of field observations

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slabs will take time to stabilize. Use caution when heading to wind prone locations.

  • Be careful with reverse loaded pockets of wind slab at ridgeline.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

Dec. Surface hoar to 6mm can be found in sheltered locations up to 2000m and is reactive to skier traffic.

  • Be aware of the potential for avalanches due to buried surface hoar in isolated areas.
  • Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Be cautious of thick to thin snowpack areas being likely trigger locations. The wind slabs or persistent slabs have the potential to step down to the weakness at the base of the snowpack.

  • Use caution in thin snowpack areas.
  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3.5

Valid until: Dec 28th, 2020 4:00PM