Avalanche Forecast

Issued: Nov 18th, 2013 8:33AM

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

danyelle magnan, Parks Canada

Glacier.

The early season snowpack was rapidly loaded by this storm. Natural avalanches, triggered by windloading, may run into avalanche fans. Minimizing exposure to the steep paths up Connaught by spreading out and taking the high line is recommended.

Summary

Weather Forecast

The snow will continue through Tuesday. Expect another 10cm in the next 24 hours, with moderate to strong SW winds transporting snow. Overnight on Tuesday temps will drop and the skies will clear. Wednesday looks sunny with alpine temps around -16.

Snowpack Summary

We've received about 70 cm of snow in the last 5 days. This snow has been transported by strong winds in the alpine forming windslabs on ridgecrests and loaded pockets of snow on lee slopes above treeline. A surface hoar layer buried on Nov 12, most prevalent around1900m, collapsed easily in tests and may become reactive as the slab above develops.

Avalanche Summary

Poor visibility during the storm made avalanche observations difficult. Several natural avalanches occurred from steep avalanche paths adjacent to the highway, running to the beginning of their fans. There have been no reports of avalanches from backcountry skiers; if you have any reports please pass this important info on to us!

Confidence

Due to the number of field observations

Problems

Wind Slabs

The SW winds have lots of snow to transport. Windslabs have formed along ridgecrests, Fat loaded drifts have also formed on lee slopes. Strong winds are forecast to continue, and natural avalanche from steep lee paths are possible.

Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

It snowed steadily over the weekend, with ~70cm falling in 5 days. This was magnified by wind loading. This has rapidly loaded the snowpack. Where it exists a surface hoar layer may become reactive.

Dig down to find and test weak layers before committing to a line.Choose regroup spots carefully.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Nov 19th, 2013 8:00AM