Avalanche Forecast

Issued: Feb 3rd, 2018 4:09PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Persistent Slabs and Storm Slabs.

Parks Canada william lawson, Parks Canada

Dangerous avalanche conditions persist in the forecast region. Avoid exposure to overhead hazard while traveling at all elevations.

Summary

Weather Forecast

Valley bottom temperatures will drop Saturday night with a slight inversion forecast for Sunday, alpine temps expected around -12 to -17. A brief break in precipitation Sunday will bring clears skies before another small system moves in Monday. Winds are expected to remain in the light to moderate range through Sunday.

Snowpack Summary

25-40cm of new snow and moderate winds have developed new storm slabs in the upper snowpack. The main concern in the snowpack continues to be the three persistent weak layers of surface hoar and/or facets that are found between 50 and 100cm down. We continue to observe sudden test results, whumphing and large propagations on these layers.

Avalanche Summary

Lake louise ski patrol reported numerous natural and skier triggered avalanches in the recent storm snow with one large explosive result stepping down to a persistent weak layer (size3). We have seen big natural avalanches over the last few days as the snowpack remains prime for triggering.

Confidence

Problems

Persistent Slabs

An icon showing Persistent Slabs
Three weak layers exist in the upper snowpack: Jan 16, Jan 6, and Dec 15. All are a mix of sun crust, surface hoar and facets depending on the aspect and elevation. Destructive avalanches have occurred on these and will continue over the few days.
Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.Avoid all avalanche terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3.5

Storm Slabs

An icon showing Storm Slabs
20-40cm of recent storm snow has developed a reactive storm slab at higher elevations, numerus skier triggered avalanches have been reported on this layer. Stick to non-avalanche terrain until the storm snow has a chance to settle.
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 4th, 2018 4:00PM