Avalanche Forecast

Issued: Feb 4th, 2013 9:26AM

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

mpeter, Avalanche Canada

South Coast.

Be aware of your local conditions. If more than 20cm of new snow falls where you are traveling, the DANGER rating could be too low.

Summary

Confidence

Fair - Timing of incoming weather is uncertain on Tuesday

Weather Forecast

Tuesday: Expect flurries to build through the day, with more intensity in the Coquihalla area and lower accumulations on the Duffey. 15-20cm are possible through the day. Expect moderate to strong southwest winds and alpine temperatures reaching -6.Wednesday: The storm continues with another 10cm possible. Strong southerly winds persist with temperatures reaching -8.Thursday: Snowfall should taper through the day, with winds turning more northerly and abating somewhat. Alpine temperatures should reach -6.

Avalanche Summary

Isolated loose wet sluffs have been reported. The Coquihalla area has seen some glide slabs release on slopes with granite slabs as the ground cover. Avalanche activity will increase as we move into the next storm.

Snowpack Summary

Old wind slabs can be found behind ridges, ribs and on lee slopes (NW-NE). Sun crusts have formed on South and West facing slopes. The upper snowpack is showing continued settlement and gaining strength. Down 20-50 cm sits a persistent interface comprising of crusts, facets and surface hoar crystals. Recently, this layer has been reactive onlyÂ in sheltered areas at treeline and below where the surface hoar lingers. The mid pack is generally well settled. The average snowpack depth at treeline is 180 cm.As the storm arrives and intensifies, expect new windslabs on lee features.

Problems

Wind Slabs

Isolated windslabs may still be reactive in isolated lee and cross loaded features. New windslabs will form as the storm arrives

Make observations and assess conditions continually as you travel.>Be cautious as you transition into newly wind affected terrain.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

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 5th, 2013 2:00PM