Avalanche Forecast

Issued: Mar 18th, 2013 4:00PM

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

snow safety, Parks Canada

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.

Summary

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

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

Valid until: Mar 19th, 2013 4:00PM