Avalanche Forecast

Issued: Feb 6th, 2013 9:24AM

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.

There is considerable variability across the region in terms of new snow amounts (higher in the Coquihalla and Allison Passes). Be locally aware as to what's happening where you are traveling.

Summary

Confidence

Fair

Weather Forecast

Thursday: Expect clouds to lift and precipitation to tail off, replaced by mixed skies later in the day. Winds should be light from the north with alpine temperatures reaching -4.Friday: Mostly sunny, with continued light northerly winds and temperatures reaching -4.Saturday: The ridge remains in place, yielding light northerlies and mostly sunny skies. Alpine temperatures may reach -1 with the freezing level climbing to 1200m.

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

Dribs and drabs of new snow continues, with occasional heavier pulses. Consistent southwesterly winds have redistributed this 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. Overall the storm snow is settling and bonding well with poorer bonding observed on solar aspects with a well developed crust.The January 23rd interface (crusts, facets and surface hoar crystals) lingers. 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). The mid and lower snowpack 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 your local zone.

Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>Avoid freshly wind loaded features.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

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 7th, 2013 2:00PM