Avalanche Forecast

Issued: Dec 6th, 2013 8:00AM

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.

danyelle magnan, Parks Canada

Glacier.

While the Parks Canada website is unavailable, call 250-837-SKIS or visit the Rogers Pass Centre for information on Winter Restricted Areas status.

Summary

Weather Forecast

The arctic ridge of high pressure will continue to dominate the region through the weekend. It should remain cold, with alpine temps of -20 to -26, dry and mostly clear. Alpine winds will generally be light from the N, except on Sunday when they are forecast to be moderate gusting to strong.

Snowpack Summary

Surface facetting and new surface hoar growth is occurring. Windslabs are widespread above treeline. The November 28 surface hoar/crust interface is down 30-40 and the November 12 surface hoar layer is down 60-110cm. These layers are of most concern where the overlying snow has formed a cohesive slab.

Avalanche Summary

No new natural avalanches were observed yesterday. On Tuesday, a group reported easily ski cutting a few pockets of soft windslab in 8812 bowl. Earlier in the week, several large avalanches natural avalanches occurred. They all appeared to be 30-40cm deep, likely on the Nov 28 surface hoar/crust.

Confidence

Problems

Wind Slabs

Strong southerly winds earlier this week, shifted to strong northerly before dropping off. Widespread wind transport created windslabs on all aspects. They likely exist in unusual areas due to the reverse loading and may catch you by surprise.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

A layer of concern exists down 30-40 which consists of widespread surface hoar and sun crust on steep solar aspects. It may be stubborn to trigger but recent avalanches on this layer have been large and propagated widely.

Dig down to find and test weak layers before committing to a line.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 7th, 2013 8:00AM