Avalanche Forecast

Issued: Nov 20th, 2013 8:20AM

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

Jon Schleiss, Parks Canada

Glacier.

The first major avalanche cycle of the season peaked yesterday, please remember to use caution on this first blue sky day and ride safely.

Summary

Weather Forecast

Temperatures in the alpine starting at -21 rising to -14 with light to moderate ridgetop winds which are forecast to be gusty this evening. There is no snow in the forecast for the foreseeable future and temperatures are on a steady rise towards the weekend with daytime highs forecast to be -5 for Friday.

Snowpack Summary

Heavy snow fall and strong winds have rapidly loaded the snowpack. Snowpack tests yesterday found several reactive storm snow instabilities in the easy range in the top 75cm. The Nov 12 surface hoar layer, now down ~1m, gave sudden planar results on an E aspect at 1980m. All reports from the field indicated slabby conditions.

Avalanche Summary

A widespread natural avalanche cycle started overnight on the 19th. Numerous size 2.5-3 avalanches occurred in paths along the highway east and west of Rogers Pass. Most notably, Laurie, Junction E, and Crossover slidepaths had size 3 avalanches running into the fans with some running right into the creek in the valley bottom.

Confidence

Problems

Storm Slabs

Yesterdays avalanche cycle which produced avalanches up to size 3 with many running right to the valley bottom has slowed down due to a drop in temperatures. Test any open slope in the alpine and treeline before committing to it and use caution.

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Expect heavy trailbreaking until the storm snow settles out.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Wind Slabs

Heavy snowfall and strong winds have created slab avalanche conditions. Use caution when venturing into open treeline and alpine areas. Avalanches to size 3 were running yesterday during the storm.

Be cautious as you transition into wind affected terrain.Test slopes before committing to them.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Valid until: Nov 21st, 2013 8:00AM