Avalanche Forecast

Issued: Apr 11th, 2014 9:48AM

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

mbender, Avalanche Canada

South Columbia.

Summary

Confidence

Fair - Freezing levels are uncertain on Monday

Weather Forecast

Saturday: Mix of sun and clouds with possible flurries. Light north winds. Freezing level 1600m.Sunday: Mostly clear and sunny. Light northwest winds. Freezing level 1500m.Monday: Mix of sun and cloud. Light west winds. Freezing level 2400m with a possible temperature inversion.

Avalanche Summary

Recent reports on are limited to loose wet avalanches on solar aspects size 1-2.

Snowpack Summary

Warm temperatures resulted in the freezing level reaching to almost 2500m early this week. This has helped to settle out last weeks storm snow, it's reported to be bonding well to the old surface. Strong winds out of both the SW and NW have redistributed what little dry snow still exists at upper elevations into wind slabs immediately lee of ridge crest.Three persistent weak layers exist in the highly variable snowpack of the South Columbia's:The mid-March sun crust/surface hoar layer down 50-80cm seams to have gone dormant for the time being.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 could wake this layer up, which would result in very large and destructive avalanches.

Problems

Wind Slabs

Wind slabs immediately lee of ridge crest may still be sensitive to human triggering.

Give cornices a wide berth when travelling on or below ridges.>Be careful with wind loaded pockets, especially near ridge crests and roll-overs.>Assess start zones carefully and use safe travel techniques.>

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

A bomber spring snowpack is still weeks away. For now, 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 wake the sleeping giant.

Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be aware of the potential for very large, deep and destructive avalanches due to the presence of deeply buried persistent weak layers.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

4 - 8

Valid until: Apr 12th, 2014 2:00PM