Avalanche Forecast

Issued: Nov 13th, 2012 4:28PM

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

brian webster, Parks Canada

Banff Yoho Kootenay.

Summary

Weather Forecast

Mixed sun and cloud for tomorrow with freezing levels around 1300 meters.. No snow forecasted through the end of the week.

Snowpack Summary

25 to 35 cm of last weeks storm snow overtop of Nov. 6 rain crust. This crust is well developed up to 2500 m and disappears around 2700m. Pit at Bow Summit showed mod. shears within crust with compression test. Various hard and soft slabs found in alpine

Avalanche Summary

No new naturals avalanches observed today.Â

Confidence

Problems

Wind Slabs

Various hard and soft wind slabs (20-50cm thick) in the alpine are sitting on the Nov.6 crust and producing moderate shears with compression test. Slabs becoming less reactive but still possible for a skier to trigger these slabs in steep lee terrain

Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

In helicopter flight over the Wapta on Sunday several deep slabs size 2-3 were been noted on isolated steep alpine slopes . Failure plane was at the bottom of the snow pack on firn or glacier ice.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Nov 14th, 2012 4:00PM