Avalanche Forecast

Issued: Apr 16th, 2014 9:08AM

The alpine rating is moderate, 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

Purcells.

Avalanche danger can rise very quickly with warming and solar radiation. Be aware of changing conditions and overhead hazards.For more insight into spring danger ratings, check out our Blog Post.

Summary

Confidence

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

Weather Forecast

Thursday: Â Light to locally moderate precipitation. Winds moderate west. Freezing level 1800m.Friday: Â Overcast with flurries or light snow. Moderate northwest Â winds. Freezing level 1500m.Saturday: Mix of sun and cloud. Light west wind. Freezing level 2200m.

Avalanche Summary

Recent reports include loose wet avalanches running to size 1.5 solar aspects.

Snowpack Summary

There is moist/wet snow and/or a supportive crust on all aspects and elevations except for high elevation north-facing terrain. Three persistent weak layers exist in the highly variable snowpack of the Purcells. -The mid-March sun crust/surface hoar layer down 50-80cm seem and the early-March crust/facet/surface hoar layer down around 80-120cm seem to be laying dormant for the time being. -The mid-February crust/facet/surface hoar combo is typically down 60 - 120cm. 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.-Weak basal facets exist in many areas, but triggering is unlikely.

Problems

Loose Wet

Expect to see an increase in avalanche activity with forecast rain at lower elevations or on solar aspects if the sun comes out for extended periods of time.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

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

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.>Be cautious as you transition into wind affected terrain.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 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.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

4 - 8

Valid until: Apr 17th, 2014 2:00PM