Avalanche Forecast

Issued: Nov 22nd, 2012 9:01AM

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

robert hemming, Parks Canada

Glacier.

The winter permit system is not yet in effect but is scheduled to come into effect on Friday, November 23rd. Click here for more information on how to obtain annual and daily winter permits.

Summary

Weather Forecast

Ridge of high pressure over the park will produce some clearing today. The ridge will break down later today as a warm front associated with a developing low pressure system moves over the area producing cloud and precipitation overnight and tomorrow

Snowpack Summary

Now over 90mm of load on the Nov 6 crust, down 60-100cm. Whumphing, sudden collapse and sudden planar results have been reported on this layer recently. A cohesive storm slab has formed and appears to be reactive where it overlies the Nov 16 sun crust.

Avalanche Summary

2 size 2 natural observed above the highway corridor on the west side of the pass yesterday, limited visibility.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Wind Slabs

Moderate to strong S-SW winds redistributied recent storm snow yesterday afternoon and overnight, forming windslabs on lee slopes.

Assess start zones carefully and use safe travel techniques.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

Reports continue of whumphs, sudden collapse and sudden planar results on this layer. Incoming solar radiation during clear periods may change slab properties rapidly today.

Assess start zones carefully and use safe travel techniques.Make observations and assess conditions continually as you travel.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Nov 23rd, 2012 8:00AM