Avalanche Forecast

Issued: Apr 12th, 2014 9:39AM

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

mbender, Avalanche Canada

Cariboos.

Summary

Confidence

Fair - Freezing levels are uncertain on Monday

Weather Forecast

Sunday: Mostly clear and sunny. Light northwest winds. Freezing level 1700m..Monday: Mix of sun and cloud. Light west winds. Freezing level 2100m.Tuesday: Cloudy with scattered flurries. Light southwesterly winds. Freezing level 1700m.

Avalanche Summary

Recent reports indicate explosives triggered avalanches running to size 3.5 on northerly aspects in the alpine. A size 2.5 natural cornice triggered avalanche was also reported from a southeast aspect in the alpine.

Snowpack Summary

Up to 50cm of recent storm snow accumulations from the past few days in the alpine have been redistributed by moderate west and southwest winds creating wind slabs in alpine lee features. This new snow sits on a crust formed by warm temperatures resulting from the freezing level reaching to almost 2200m early last week. Three persistent weak layers exist in the highly variable snowpack of the Cariboos:The mid-March sun crust/surface hoar layer down 50-80cm still has potential for human-triggering in isolated areas. The early-March crust/facet/surface hoar layer down around 80-120cm has become less susceptible to human triggering, but still has the capacity to produce large avalanches.The mid-February crust/facet/surface hoar combo is typically down 150 - 200cm. Direct triggering of this layer has become unlikely, however, cornice fall, a smaller avalanche in motion or prolonged warming may wake this layer up, which would result in very large and destructive avalanches.

Problems

Loose Wet

Expect to see an increase in avalanche activity on solar aspects as the sun stays out for extended periods of time.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Wind Slabs

Storm and wind slabs are most sensitive to human triggering immediately lee of ridge crest and mid slope features like ribs.

Avoid wind loaded features, especially slopes immediately lee of ridge crest and mid slope roll overs.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Deep Persistent Slabs

The potential for very large deep slab avalanches needs to remain on your radar. Cornice fall, strong solar, warming temperatures or a surface avalanche in motion could act as triggers.

Be aware of the potential for very large, deep and destructive avalanches due to the presence of deeply buried persistent weak layers.>Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

4 - 8

Valid until: Apr 13th, 2014 2:00PM