Avalanche Forecast

Issued: Jan 4th, 2012 8:06AM

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

Parks Canada sylvia forest, Parks Canada

10cm new at Fidelity, -2 to-6, winds S 25. Very mild temperatures, high freezing levels, the possibility of rain at lower elevations and slabbing of new snow at treeline and in the alpine means that conservative route selection should be used today

Summary

Problems

Persistent Slabs

An icon showing Persistent Slabs
10-15cm of snow is forecasted for later today, with high freezing levels (into the alpine) has the potential to overload the Dec. 11 persistent weak surface hoar layer. Natural and human triggered avalanches on this layer can be expected today.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 4

Wind Slabs

An icon showing Wind Slabs
Isolated wind slabs at ridge tops are continuing to form, causing whumphing and cracking in shallow and cross-loaded areas. Failure of these slabs could step down to the deeper buried surface hoar layers which are likely to propagate widely.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
In the high alpine basal weaknesses exist and may cause large or very large avalanches. These may slide from large triggers or during periods of heavy storm loading. Large glide cracks failing near ground are also a significant concern this year.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 4

Valid until: Jan 5th, 2012 8:00AM