Archived

Avalanche Forecast

Apr 11th, 2013–Apr 12th, 2013

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Banff Yoho Kootenay.

It will feel wintery the next few days, with continued storms piling into us from the west. Danger ratings will increase during the peaks of each storm wave.

Weather Forecast

Clear skies should greet us tomorrow morning. Then another storm is lined up to pass through the forecast region Friday evening, delivering 10-15cm of snow with moderate westerly winds and freezing levels below 1300m.

Snowpack Summary

We received 10-15cm overnight, accompanied by moderate to strong SW winds. This will have developed into soft slabs in the alpine. Expect the slabs to be touchy for the next day or two. These slabs overlay 10-30cm of previous storm snow, which rest on suncrusts on solar aspects and facetted snow on polar aspects.

Avalanche Summary

Touchy soft slabs in the Lake Louise area and up highway 93N were reported in the immediate lees of ridgecrests. Slabs were on average 10-15cm thick, but in some cases up to 30cm thick.

Confidence

Forecast snowfall amounts are uncertain

Avalanche Problems

Storm Slabs

Isolated soft slabs in the immediate lee of alpine features were reported in the Lake Louise area, as well as up 93N. 10-15cm thick slabs were touchy and propagating upwards of 20m from skiers/riders.

Avoid lee and cross-loaded terrain near ridge crests.Excellent conditions on sheltered Northerly aspects.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Loose Dry

Fast sluffing of the storm snow on underlying crusts was reported in the Sunshine area today. This is a definite concern for skiers and climbers in gully/couloir features.

Be very cautious with gully features.Be cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Cornices

The combination of westerly winds, new snow, and higher humidity values has allowed some rapid growth of cornices along ridge-line features. These will be touchy if the strong, spring sunshine hits them Friday morning.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2