Avalanche Forecast

Issued: Apr 18th, 2014 9:00AM

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

esharp, Avalanche Canada

South Columbia.

Avalanche danger can quickly rise above what is forecast 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 - Due to the number of field observations

Weather Forecast

Synopsis: A weak ridge of high pressure will develop over the interior of the province this weekend. Convective flurries may be possible. On Monday the ridge will shift eastward as the next system moves in over the South Coast.Saturday: Sunny with cloudy periods / Light southerly winds / Freezing levels between 1500-2000mSunday: Sunny with cloudy periods and a chance of flurries / Light westerly winds / Freezing levels between 1800-2000mMonday: Cloudy periods with flurries. / Light south winds / Freezing levels between 2000-2700m

Avalanche Summary

There have been recent reports of widespread small storm snow avalanches failing above the latest crust in steep terrain. At lower elevations and on solar aspects small loose wet avalanche continue to be triggered on steep slopes.

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. Soft winds slabs may be found in the immediate lee of ridges and ribs. A second melt-freeze crust buried at the beginning of April can be found down 40-55cm. This layer has been variably reactive in snowpack tests.Three persistent weak layers exist in the highly variable snowpack of the South Columbia region: 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 inactive. The mid-February crust/facet/surface hoar combo is typically down 150 - 200cm. Human triggered avalanches on this layer are unlikely. Larger triggers such as cornice fall, a smaller avalanche in motion or prolonged warming could wake this layer up, resulting in very large and destructive avalanches.

Problems

Loose Wet

Expect to see an increase in avalanche activity if the sun comes out for extended periods of time.

Cornices become weak with daytime heating, so travel early on exposed slopes.>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

Newly formed wind slabs immediately lee of ridge crest may be sensitive to human triggering.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 19th, 2014 2:00PM