Avalanche Forecast

Issued: Apr 17th, 2014 9:08AM

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.

esharp, Avalanche Canada

Purcells.

Avalanche danger can rise very quickly with warming temperatures and/or brief periods of sun. Be aware of changing conditions and overhead hazards.For more insight into spring danger ratings, check out our Blog Post.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

Tonight and Friday: Flurries (total accumulation: 5-10cm) / Light westerly winds / Freezing level 1800mSaturday: Cloudy with sunny periods and isolated flurriesÂ / Light westerly windsÂ / Freezing level 2000.Sunday:Â Flurries (total accumulation: 5-10cm) / Light westerly winds / Freezing level 2000m

Avalanche Summary

There have been no new avalanche observation

Snowpack Summary

A recently buried, supportive crust can be found near the surface of the snowpack on all aspects and elevations except for high elevation north-facing terrain.Three persistent weak layers still exist in the highly variable snowpack of the Purcells: The mid-March sun crust/surface hoar layer down 50-80cm 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.Â The resulting avalanche would be very large and destructive.At the base of the snowpack weak basal facets can be found in many areas, however triggering this layer 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

New wind slabs immediately lee of ridge crest may 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.>

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 sun, 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 18th, 2014 2:00PM