Avalanche Forecast

Issued: Feb 14th, 2013 9:50AM

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

triley, Avalanche Canada

Cariboos.

New wind slabs have been reported to be deeper than expected and easy to trigger. New storm slabs are also reported to be easy to trigger and running fast on a combination of crusts and buried surface hoar.

Summary

Confidence

Fair - Due to variable snowpack conditions for the entire period

Weather Forecast

Overnight and Friday: Some light precipitation is expected over the Northern parts of the region. Strong Northwesterly winds should diminish to moderate Westerly during the day. Alpine temperatures rising up to about -2.0 during the day as the freezing level rises to about 1300 metres.Saturday: Expect 5-10 cms of snow as a trough moves across the interior regions. Winds should be moderate Westerly with strong Northwesterly gusts. Alpine temperatures are expected to cool down to about -7.0 as a cold front associated with the trough moves through the region.Sunday: Another ridge of high pressure is expected to build over the interior, bringing cooler temperatures and drier conditions.

Avalanche Summary

Natural avalanches were reported up to size 3.0 from Wednesday. The new storm slab and wind slabs have been reported to be easily triggered and result in avalanches size 2.0-2.5. Some areas experienced remote triggering of the storm slab from adjacent terrain.

Snowpack Summary

There is a lot of variability in the new snow amounts across the region. New storm slabs are between 10-40 cms deep, and new wind slabs are up to 70 cms deep due to strong Northwest winds transporting the available new snow. Tests are showing easy to moderate shears at the storm snow interface. There are a couple of deeper buried surface hoar and crust layers that have been giving hard resistant planar results in snow profile tests. These deeper layers are not expected to be triggered by light additional loads, but may be triggered by storm snow avalanches in motion, or cornice fall.

Problems

Wind Slabs

New wind slabs are reported to be up to 70 cms deep in some areas and easy to trigger by human activity.

Avoid freshly wind loaded features.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Storm Slabs

A new soft storm slab has developed above surface hoar and sun crusts that developed during the recent clear weather. The new storm slab is between 20-40 cms deep and reported to be easy to trigger by skiers or snowmobilers (riders).

The new snow will require several days to settle and stabilize.>Choose conservative lines and watch for clues of instability.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Persistent Slabs

There are older layers of buried surface hoar and crusts that are buried down about 80-110 cms. These layers continue to show results in snow profile tests and may be triggered by large additional loads.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Avoid open slopes and convex rolls where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Feb 15th, 2013 2:00PM