Avalanche Forecast

Issued: Nov 24th, 2013 8:03AM

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

catherine brown, Parks Canada

Glacier.

The Winter Permit System comes into effect on Tuesday, November 26th. Click here: Winter Permit Information, for further info.

Summary

Weather Forecast

Freezing levels will rise to 1800 m today. An inversion today with warm air aloft will rise alpine temperatures to around 0 deg. Ridge top winds will be light with no precipitation. This stable weather pattern with high freezing levels is forecast to continue until Wednesday. Snow is forecast in the park for Thursday.

Snowpack Summary

Cold temperatures and clear skies have facetted the upper snowpack and a health layer of surface hoar is growing. Solar aspects are forming surface crusts. The November 12th surface hoar layer is buried between 50 and 110cm. Its distribution is valley dependant. It had been observed up to 2500m on Mt Abbott in the Asulkan Valley.

Avalanche Summary

Solar induced slides on south through west facing slopes are possible today if the sun stays out this afternoon. Rock outcrops and trees can be trigger points. Use caution in this terrain, especially if the surface snow is moist. Last Wednesday, a size 3.5 natural avalanche occurred on the Dome, running on the Nov. 12th surface hoar down 100cm.

Confidence

Due to the number of field observations

Problems

Persistent Slabs

A weak layer is buried down 50 to 110 cm. Use caution on steep, planar slopes. Riders could trigger this weak layer, especially from shallow snowpack areas. A large consequence avalanche is likely if triggered.

Avoid convexities or areas with a thin or variable snowpack.Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Wind affect has been observed at higher elevations, and wind transport was visible yesterday off the ridge tops.

Assess start zones carefully and use safe travel techniques.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 25th, 2013 8:00AM