Avalanche Forecast

Issued: Feb 7th, 2013 9:13AM

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

mpeter, Avalanche Canada

South Coast.

When the sun comes out, it could have a de-stabilizing effect on the new snow. Be cautious if the sun burn off the high cloud.

Summary

Confidence

Good

Weather Forecast

Friday: Expect mostly sunny skies, with a chance of high, thin cloud. Winds should be light from the north and alpine temperatures should reach -4.Saturday & Sunday: Expect the ridge to settle in. Sunny skies, light northerly winds and alpine temperatures reaching -1 each afternoon.

Avalanche Summary

Natural activity up to size 2.0 has been observed on northeast aspects where the recent storm snow is 25cm or deeper. Be locally aware of how much new snow you are dealing with.

Snowpack Summary

The dribs and drabs of new snow has ended. Around 30-40cm fell on average, with more (up to 65cm) in the Coquihalla area.Â Consistent southwesterly winds during the storm period has redistributed the new snow into fresh windslabs on lee terrain features in the alpine and at treeline. The newly buried surfaces are old wind slabs (behind ridges, ribs and on lee slopes) and sun crusts on south and west facing slopes. In isolated locations, this interface is small surface hoar. Down a further 20-50 cm sits a persistent interface comprising of crusts, facets and surface hoar crystals. Recently, this layer has been reactive only in sheltered areas at and below treeline where the surface hoar lingers. A partial block RB6 is the only recent test score that we have seen on this interface (Duffey Lake area). There has been one size 2.0 avalanches releasing on this layer as well. The mid pack is generally well settled.

Problems

Wind Slabs

New windslabs are forming with new snow and consistent southwesterly winds. Isolated old slabs may still be reactive in lee and cross loaded features. Be locally aware of how much new snow is in the zone you are riding.

Assess start zones carefully and use safe travel techniques.>Be cautious as you transition into wind affected terrain.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 5

Persistent Slabs

Buried down 30-60 cm exists a surface hoar/crust/facet layer. This layer of concern seems to be most reactive in sheltered locations over convex rolls and steeper terrain features at treeline and below.

Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Feb 8th, 2013 2:00PM