Avalanche Forecast

Issued: Mar 8th, 2014 8:00AM

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

catherine brown, Parks Canada

Glacier.

Avalanche hazard will rise with the incoming storm. Assess condition continually as you travel today, watching for clues of instability as the snowpack deteriorates.

Summary

Weather Forecast

Warm and wet is the forecast for this weekend as intense subtropical moisture hits the region. Expect alpine temperatures around -1, 10-15 cm of snow and light ridge top winds with strong gusts. 15-20 cm of snow is forecast tonight with freezing levels remain high. 10cm of snow is forecast tomorrow with similar temps as today and westerly winds.

Snowpack Summary

Up to 60cm of heavy snow over light snow has created a touchy soft slab. This lies on top of suncrusts on solar aspects, and windslab on N and E aspects. The new slab is failing with easy to moderate results within the new snow, as well as at the old interface. The Jan 28/Feb 10 PWL is down 1.2-1.5m under a cohesive slab.

Avalanche Summary

Several size 2-3 natural avalanches were observed yesterday along the highway corridor. We are expecting a large natural avalanche cycle to occur this weekend with intense precipitation and warm temperatures. Reports indicate that the storm slab is reactive to skier triggering on steep, convex features with remote triggering a possibility.

Confidence

Freezing levels are uncertain

Problems

Storm Slabs

60 to 80 cm of warm/moist snow has formed a rider triggerable slab. Natural avalanches are expected this afternoon with rising temperatures and more snow load. Remote triggering is also a concern, watch out for adjacent slopes.

Choose well supported terrain without convexities.Minimize exposure to avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

A deep weak layer buried at the end of January is down around 1.5 m. Although we have not observed any recent skier-triggering of this layer, artillery control triggered this layer on the west side of the park, releasing a size 3.5.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.Carefully evaluate and use caution around thin snowpack areas.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 4

Valid until: Mar 9th, 2014 9:00AM