Avalanche Forecast

Issued: Feb 28th, 2020 4:00PM

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

Parks Canada Lisa Paulson, Parks Canada

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Expect new windslab development overnight and Saturday.  Remain cautious in variable snowpacks where it remains possible to trigger the basal weakness from a shallow spot.  Otherwise - great skiing can be found in many locations!

Summary

Weather Forecast

Friday Night: Flurries (10-20 cm) with moderate to strong SSW winds.  The higher amounts are for the Northern part of the region along the Divide.

Saturday/Sunday: Cooler temperatures with highs of -8C.  Saturday night temperatures fall to -17, but climb to -11 C with lighter wind and a mix of sun and cloud forecasted for Sunday.

Snowpack Summary

Wind effect in the alpine due to gusty SW winds over the past week.  10-20 cm of recent snow over buried sun crust 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

Isolated small thin wind slab in the immediate lees were reported today, otherwise no new avalanches were reported today.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

An icon showing Wind Slabs

New windslabs will develop overnight and through the day tomorrow with forecasted snow and moderate to strong SSW wind.  These new slabs will overlie the older thin windslabs we have described on lee features.

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

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 (<130cm) 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 - 3.5

Valid until: Feb 29th, 2020 4:00PM