Avalanche Forecast

Issued: Feb 26th, 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 Stephen Holeczi, Parks Canada

Watch locally for wind slab development Thursday. Also be curious about snowpack depths as thinner areas will likely have more pronounced basal facets. Great skiing in sheltered areas.

Summary

Weather Forecast

Alpine winds at 3000m will be in the 70kmh range Thursday with 5cm of snow possible. Temperatures at treeline will range from -10 to -4C. Expect 5cm Friday and 10cm on Saturday.

Snowpack Summary

10-20 cm of recent storm snow covers previously formed wind slabs in lee areas, and buried sun crusts on steep solar aspects. The Feb 1 rain crust is down 20-50 cm and present below 1900 m. In thin snow pack areas a dense mid-pack sits over a weak, faceted base. Thick snowpack areas have a denser base with few weaknesses.

Avalanche Summary

Local ski hills reported newly formed windslab isolated to immediate lee slopes off ridge crest. Ski patrol were able to produce size 1 avalanches on this layer with ski cuts. Some large sloughs out of extreme cliffed terrain.

Confidence

Wind speed and direction is uncertain on Thursday

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs are present in lee areas of the high alpine. So far these are small but have been reported as a touch more reactive than yesterday.

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Avalanche activity on the basal facets has slowed down but the weakness in the snowpack remains a concern. These are hard to predict, but are most likely in areas with a thin snowpack (<150cm) where the basal facets and depth hoar are prominent.

  • Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.
  • Use caution in thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Feb 27th, 2020 4:00PM