Avalanche Forecast

Issued: Apr 1st, 2017 8:12AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is considerable. Known problems include Storm Slabs, Loose Wet and Cornices.

ian gale, Parks Canada

Glacier.

Warm temperatures and new snow will keep avalanche hazard elevated. There is a complex mix of avalanche problems as we start to transition to a more typical spring snowpack.

Summary

Weather Forecast

Today will be cloudy with scattered flurries, with freezing level rising to 1500m and winds from the SW at 20-30kph. A frontal system passing over the southern province will bring 5-10 cm to Rogers Pass today before a ridge of high pressure moves in and brings clearer skies and warmer temps.

Snowpack Summary

March was a snowy month with snowfall in the alpine almost every day. In the last week we received 60cm at treeline. Yesterday daytime warming turned the surface snow moist on all but due north facing slopes in the alpine. Multiple crusts exist in the upper snowpack at treeline & below. Cornices keep growing in the alpine and should not be trusted!

Avalanche Summary

Yesterday numerous moist avalanches were observed triggered by the intense solar and warm daytime temps. A field team observed a sz 2 glide crack release on a South east aspect below treeline. There are minimal reports from skiers/riders in the back country as fewer people are out there and we transition into spring.

Confidence

Freezing levels are uncertain

Problems

Storm Slabs

10 cm of heavy snow with winds gusting to 40 kph will bond poorly to the moist snow surface after yesterdays warm temps. If triggered storm slabs have the potential to step down to deeper layers buried in March or February.

Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Loose Wet

Warm temps yesterday and new snow overnight will insulate the moist upper snowpack. If the precip continues into the afternoon we can expect rain at lower elevations which will increase the potential for wet slabs or glide avalanches.

If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

2 - 3

Cornices

Cornices are very large right now and can fail unpredictably - if this happens persistent weak layers deep in the snowpack can be triggered, resulting in very large avalanches.

Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 2nd, 2017 8:00AM