Archived

Avalanche Forecast

Mar 18th, 2013–Mar 19th, 2013

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

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.

Touchy conditions will be exacerbated tomorrow with solar effect. Don't let the blue skies lure you out of a conservative mindset.

Weather Forecast

A short lived ridge Tuesday will be followed by another fairly strong system Wednesday bringing more snow and wind and warming temps.

Snowpack Summary

Another 10 cm of new and some more strong winds has added again to the storm slab condition. Winds from both the west and north east have loaded most open slopes at and above treeline. In shallower areas east of the divide, the snow rests on a very weak base of facets. South aspects have a crust. Triggering is likely.

Avalanche Summary

Widespread avalanche activity has been observed throughout the forecast district. Deep slabs have been observed in many areas to size three. Large cornice falls, storm slabs and deep slabs are still a concern.

Confidence

Intensity of incoming weather systems is uncertain on Wednesday

Avalanche Problems

Storm Slabs

Storm snow accumulations since last Tuesday have been 60-80 cm or more. Both northerly and westerly winds with the storms have created storm slabs on most aspects. Touchy conditions and potential for large avalanches persist.

Use conservative route selection, stick to moderate angled terrain with low consequence.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 3

Cornices

The cornices are very large and touchy with recent high humidity and winds. Avoid lee slopes beneath them.

Stay well to the windward side of corniced ridges.Pay attention to overhead hazards like cornices.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 2 - 3

Persistent Slabs

In shallower areas east of the divide deep slabs have been observed failing on the lower facetted snowpack

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 3