Avalanche Forecast

Issued: Feb 25th, 2013 8:00AM

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

ali haeri, Parks Canada

Glacier.

Buried surface hoar reactive to rider triggering with larger propagation, chose your terrain carefully.

Summary

Weather Forecast

Low pressure system over the region today is forecast to bring light to moderate amounts. Snow tapering off by Tuesday morning with sunny breaks by the afternoon. The next system will arrive Tuesday night with light precipitation into Wednesday.

Snowpack Summary

50cm of new snow in the past 4 days. Slab over Feb 12 surface hoar/crust layer 40-55cm thick, fist to 1 finger snow. Well settled mid pack with no significant layers below Feb 12 surface hoar.

Avalanche Summary

Yesterday: A skier remote triggered size 2.0 slab avalanche from 30m away. 2010m, North aspect, 35-40degrees, 42cm deep, 100m wide X 100m long on the Feb 12 SH sz 3-8.3 avalanches in the highway corridor size 1.5 to 2.0.

Confidence

Intensity of incoming weather systems is uncertain on Monday

Problems

Persistent Slabs

More load over the surface hoar layer buried 40-55cm. This layer is reactive to rider triggering and remote triggering. The overlying slab will continue to produce avalanches with larger propagation and more consequence for the foreseeable future.

Dig down to find and test weak layers before committing to a line.Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Dry

20cm of low density snow over the last 48hrs will produce fast sluffing is sufficiently steep terrain. With enough mass this may trigger the deeper instability.

Be cautious of sluffing in steep terrain.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

New snow has buried previous wind slab in the alpine. Look for a stiffer slab beneath the fresh at higher elevations. Winds are forecast to pick up creating new slabs.

Avoid freshly wind loaded features.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 26th, 2013 8:00AM