Avalanche Forecast

Issued: Mar 25th, 2014 9:13AM

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

triley, Avalanche Canada

Northwest Inland.

Summary

Confidence

Fair - Wind effect is extremely variable

Weather Forecast

Overnight and Wednesday: Moderate Easterly winds overnight combined with flurries and cool temperatures. Strong outflow winds during the day with freezing levels close to valley bottoms.Thursday: Continued flurries and cool temperatures combined with moderate Easterly outflow winds.Friday: A chance of some sunny periods in the afternoon. Freezing levels below 500 metres.

Avalanche Summary

No new reports of avalanches.

Snowpack Summary

The recent storm snow (40-50 cm) has been transported into pockets of wind slab by moderate Southwest winds in the South of theÂ region and by Easterly winds in the North of the region. The storm slab is sitting on the March persistent weak layer of crusts/facets/surface hoar that is widespread across the region. A late January/early February crust/facet/surface hoar combo is still showing up in snowpack tests with moderate to hard shear test results. This layer is expected to be with us for a long time, and a slide triggered on this layer could be very large and destructive.

Problems

Storm Slabs

Forecast new snow and wind are expected to add to the load of the recent storm snow. Pockets of wind transported snow may develop at higher elevations.

Minimize exposure during periods of heavy loading from new snow, wind.>Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 4

Persistent Slabs

The recent storm snow may not be well bonded to the buried weak layer of crusts/facets/surface hoar that developed during early March. Forecast cool temperatures may help to preserve this weak layer.

Be aware of the potential for large, deep avalanches due to the presence of buried weak layers>Be aware of thin areas that may propogate to deeper instabilites.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 4

Deep Persistent Slabs

The deeply buried persistent weak layer from early February continues to be a concern. Heavy loads like cornice falls or storm slab avalanches in motion may trigger this weak layer resulting in very large and destructive avalanches.

Pay attention to overhead hazards like cornices.>Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

4 - 7

Valid until: Mar 26th, 2014 2:00PM