Avalanche Forecast

Issued: Jan 31st, 2015 7:49AM

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

esharp, Avalanche Canada

Cariboos.

Windslabs may be hidden by new snow. The chance of triggering a persistent slab has decreased, but the consequences remain high.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

A series of fronts will bring between 20-30 cm of new snow to the southern interior Sunday and Monday before a ridge builds Tuesday with a return to dry conditions. Freezing levels will remain at valley bottom.

Avalanche Summary

There was a widespread avalanche cycle earlier in the week that produced numerous large to very large avalanches. Natural activity has now eased, but the present of persistent layers in snow pack suggest that it may be possible for humans to trigger an avalanche

Snowpack Summary

New snow is falling on a supportive crust, found below about 1900 m in the north or the region and 2100 m in the south. At higher elevations south west winds have formed formed wind slabs in lee features. Recent warming and subsequent cooling have helped strengthen the mid-January surface hoar layer, but it still remains a concern, especially at high elevations. The mid-December surface hoar layer is 80 to 140cm below the surface and appears to be slowly gaining strength. Basal facets could be triggered with large triggers like cornice fall in specific terrain.

Problems

Wind Slabs

Recent snow and strong winds have formed wind slabs and cornices on lee slopes above treeline. These may be hidden by new snow.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Persistent Slabs

A layer of surface hoar buried in the upper meter of the snowpack remains a concern, especially at treeline and above. A large trigger, like an avalanche in motion or cornice collapse, could trigger a deeper persistent weakness.

Choose well supported terrain without convexities.>Avoid thin or variable snowpack areas that may propagate to deeper instabilities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Feb 1st, 2015 2:00PM