Archived

Avalanche Forecast

Nov 11th, 2012–Nov 12th, 2012

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Regions: Banff Yoho Kootenay.

Early season conditions exist. Go easy. The larger avalanches observed on steep northerly slopes indicate things may be more touchy in the high alpine.. JBW

Weather Forecast

Westerly flow will develop with warming temperatures and light snowfall. Wind transport in open areas likely. Temps -4 to -10 Winds SW 20-40km/hr

Snowpack Summary

Lots of wind effect and wind slabs n open areas. Some slabs pulling out on Nov 6th Crust which is down approx 30cm. Crust is absent above 2700m. Snowpack is 1F and supports skiers at and above treeline. (Depth 60-120cm)

Avalanche Summary

Some controlled (Sc/Xe) slabs in uncontrolled areas at ski hills up to size 2: 30-60cm thick failing on Nov 6 crust. Several larger size 2-3 slabs observed today failing on firn snow about 1meter down in alpine locations along Wapta traverse

Confidence

Intensity of incoming weather systems is uncertain on Tuesday

Avalanche Problems

Wind Slabs

Wind slabs 20-50cm thick near lees of ridgecrests are sitting on the Nov.6 crust and failing in steeper locations with ski cuts and explosives, More prevalent on north and east, but can be found on all aspects due to the easterly loading.

Avoid lee and cross-loaded terrain near ridge crests.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2

Persistent Slabs

Several deep slabs size 2-3 have been noted on steep alpine slopes around Lake louise and on the Wapta. These have failed at the bottom of the snow pack on firn or glacier ice.

Use caution on N and E aspects.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