Avalanche Forecast

Issued: Apr 8th, 2012 10:02AM

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

pgoddard, Avalanche Canada

South Coast.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Monday: Clouds with scattered light precipitation. Freezing level rising to around 1800m. Light southerly winds. Tuesday: Light precipitation. Freezing level rising to around 2400m in the afternoon. Wednesday: Light to moderate precipitation. Freezing level falling to 1500m this evening.

Avalanche Summary

A size 2 skier-triggered avalanche was reported in the Duffey Lake area on Friday. It was triggered on a NE facing alpine slope and is suspected to have failed on the late March sun crust. There have also been reports of isolated natural slab avalanches to size 2.5, primarily on solar aspects during the afternoon. Loose wet activity continues on steep solar aspects.

Snowpack Summary

The snow surface consists of old wind slabs in exposed alpine terrain, spotty surface hoar on shady slopes, and a sun crust/moist snow on solar aspects. This sits on up to a metre of settling storm snow from last week. The March 27 layer is predominately a crusty interface except on north facing slopes at treeline and above where small surface hoar (5mm) may be found. It's now down 60-120 cm and has recently exhibited hard, sudden results and a Rutschblock 4 whole block failure in the Duffey Lake area. Deep persistent weaknesses linger in many colder and shallower snowpack areas. Daytime warming and sun-exposure may cause surface snow to lose cohesion and cornices to weaken.

Problems

Persistent Slabs

Persistent slab avalanches are becoming less likely, but remote triggering, step-down avalanches, and wide propagations remain possible on a weakness down 50-120cm.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 6

Loose Wet

Loose-wet avalanches are most likely on steep sunny slopes, or below treeline when temperatures are warm. A heavy wet slide could have serious consequences if you are exposed to a terrain trap.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Cornices

Large and weak cornices are a hazard in themselves, but can also act as a heavy trigger for very large avalanches on the slope below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Apr 9th, 2012 9:00AM