Avalanche Forecast

Issued: Feb 20th, 2014 8:00AM

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

chris gooliaff, Parks Canada

Glacier.

Travel on well-supported slopes with little to no overhead hazard threatening you. Large, deep avalanches are possible with the right trigger.

Summary

Weather Forecast

We should see a weak system pass through the area today, bringing 5-10cm of snow and moderate westerly winds. Freezing levels will remain in the valley bottom. As we head into the weekend, a drying trend will bring isolated flurries with cooler alpine temp's (-15*C) and light mountain-top winds.

Snowpack Summary

100-140cm of recent storm snow, deeper amounts west side of the summit, is settling over the Feb 10 facet/surface hoar/crust interface. The Jan 28 and Jan 22 surface hoar layers are 5-10cm below this interface. Test results on the Feb 10 interface are consistently sudden planar or sudden collapse in character, making this a spooky layer to watch.

Avalanche Summary

Natural activity is tapering off, but field teams experienced plenty of whumphing and cracking while traveling in supported terrain with no overhead hazard. A significant event west of the park saw wind blast from a slide from extreme terrain knock down 150 year-old timber. Things are still remaining touchy, but with higher consequence now.

Confidence

Problems

Storm Slabs

The storm slab, which is 100-140cm thick and overlies a weak interface, is becoming more cohesive. However, the bond to the underlying interface is not showing much improvement. Skier triggering of this layer will have high consequence.

Choose well supported terrain without convexities.Remote triggering is a concern, watch out for adjacent slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

Fresh wind slabs from the previous couple days are evident in open alpine and tree-line elevations. Cracking and whumphing indicate that you have found them!

Be cautious as you transition into wind affected terrain.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Cornices

The large cornices adorning ridge-tops are the large, natural trigger that could initiate a very large avalanche. They are obvious overhead hazards to be avoided for the next long while.

Pay attention to overhead hazards like cornices.Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Feb 21st, 2014 8:00AM