Avalanche Forecast

Issued: Apr 10th, 2015 9:17AM

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

bcorrigan, Avalanche Canada

South Coast.

The hazard may go higher than forecast if precipitation amounts are greater than expected.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

A series of Pacific cold fronts will move into the area late today ( Friday ) and leave 5 to 10 cm of snow at upper elevations., Winds will be moderate to strong from the south west. Freezing levels should drop to 1000m for the next few days, with daytime heating raising the freezing level to 1500m for Sunday and around 1700m for Monday afternoon. Monday may see another 5 cm of snow at upper elevations.

Avalanche Summary

Little in the way of avalanche activity from yesterday. Moist loose avalanches had been reported earlier in the week, but with falling temperatures this activity has gone dormant. Expect wind slab activity with new loading and strong winds.

Snowpack Summary

5 to 15cm of incoming precipitation will fall on a variety of crusts and old surfaces including surface hoar and facets that formed in sheltered locations during the recent clear weather. Moderate to strong south west winds will redistribute the storm snow into wind slabs on the lee sides of ridge tops. A facet/crust layer that was buried in mid-March is now approximately 50-100 cm down. Recently it was found down 55 cm near the Duffey Lake Road, and produced moderate sudden results. This remains a concern in the region because of it's potential for very large avalanches. Cornices are now large and mature and may collapse with increased loading, possibly triggering the deeply buried weak layer.

Problems

Wind Slabs

Incoming storms with strong wind will build wind slabs in lee exposed slopes

Avoid freshly wind loaded features.>Be cautious as you transition into wind affected terrain.>Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>Assess start zones carefully and use safe travel techniques.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

This slab overlying the March 25 persistent weak layer is still on the radar with professionals in the area.

Avoid convexities or areas with a thin or variable snowpack.>Be aware of thin areas that may propogate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Cornices

New snow load may tip the balance on existing, large cornice features.

Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Apr 11th, 2015 2:00PM