Avalanche Forecast

Issued: Jan 11th, 2012 8:32AM

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

eric dafoe, Parks Canada

Glacier.

A high pressure ridge will block winds and precipitation until Friday evening. Sunny skies and a slight temperature inversion today with will make alpine slopes more inviting. Watch for failure of recently formed cornices and solar releases.

Summary

Problems

Wind Slabs

Strong south winds earlier in the week formed thin slabs over the storm snow and hard slabs formed earlier. The problem is generally found to the lee of alpine ridges and on cross loaded features at upper elevations. Wide propagation is possible.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

2 - 3

Storm Slabs

50 cm of snow overlies a weakness in the storm snow which shows signs of strengthening. Tests continue to produce Mod - Hard results on this weakness. Avalanches in this layer could trigger the surface hoar layers buried in December.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Persistent Slabs

The Dec. 11 SH layer continues to produce avalanches when heavily loaded. Cornice failure is a current concern. A recent fracture line profile at 1600m showed this slab failing 110 cm deep during the last storm on Jan 6. Step down failures possible.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Jan 12th, 2012 8:00AM