Avalanche Forecast

Issued: Dec 27th, 2014 8:17AM

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

pgoddard, Avalanche Canada

South Coast.

Tricky and variable conditions. For further details see: http://goo.gl/JDfMjZ

Summary

Confidence

Fair - Wind speed and direction is uncertain

Weather Forecast

Expect light snow on Sunday, then a change to cold and clear weather with moderate to strong N-NE outflow winds.

Avalanche Summary

On Friday, several size 1 avalanches were triggered by snowmobilers below treeline in the Coquihalla area. These are likely to have failed on the mid-December surface hoar layer down about 50cm. On Wednesday skiers reported whumpfing in the Coquihalla area. On Monday we received a report of storm slabs up to size 2.5 being remote-triggering from flat areas up to 75 m away in the Coquihalla area between 1600 and 1900 m elevation. Slabs were 40-70 cm thick and were releasing on the surface hoar layer.

Snowpack Summary

New wind slabs are developing above a layer of buried surface hoar. A deeper layer of surface hoar from mid-December is buried about 60 cm down. The mid-December surface hoar layer is becoming harder to trigger, but snowpack tests are still showing that it has potential for wide propagation. It appears to be most reactive in sheltered treeline locations and may not exist across the entire region. A thick rain crust exists lower in the pack.

Problems

Persistent Slabs

A buried surface hoar layer remains a concern, especially in the southern parts of the region. This layer appears to be most reactive on north facing slopes around treeline elevation. Wind slabs may be building above this weakness.

Avoid open slopes and convex rolls where buried surface hoar may be preserved.>Be cautious as you transition into wind affected terrain.>Travel on ridgetops to avoid wind slabs on slopes below.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 28th, 2014 2:00PM