Avalanche Forecast

Issued: Feb 1st, 2015 8:32AM

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

esharp, Avalanche Canada

Cariboos.

Riding conditions will probably be good tomorrow but don't forget about the persistent weaknesses that are lurking deeper in the snow pack.

Summary

Confidence

Poor - Due to the number and quality of field observations

Weather Forecast

A frontal system will bring another 10 to15cm of new snowfall to the region overnight on Monday with scattered flurries expected for Tuesday in its wake. A ridge of high pressure building over the province Wednesday will bring dry conditions. Winds will be predominantly light from the west to southwest. 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

Up to 35cm of new snow fell over the weekend. This new snow sits on a variety of old surfaces. A crust can found below about 1900m in the north of the region and 2200m in the south. At higher elevations the new snow covers old wind slabs formed by moderate southwest winds. Several persistent week layers can be found deeper in the snowpack but are probably protected by the overlying crust at lower elevations. The mid-January surface hoar is buried between 40 and 80cm down and remains a concern at treeline and above. The mid-December surface hoar layer is now 80 to 140cm below the surface and appears to be slowly gaining strength. The base of the snowpack is faceted.

Problems

Storm Slabs

Soft slabs will form as the storm snow accumulates. At tree line and bellow these slabs sit upon a crust. In lee features this snow may hide recent wind slabs.

Be cautious of sluffing in steep terrain.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

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 could trigger deeper persistent weaknesses.

Choose well supported terrain without convexities.>Carefully evaluate and use caution around thin snowpack areas.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Feb 2nd, 2015 2:00PM