Avalanche Forecast

Issued: Apr 2nd, 2017 8:00AM

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.

Parks Canada chris gooliaff, Parks Canada

It is winter in the high alpine, with storm slabs and cornices still lurking. Lower down, a poor refreeze overnight has kept avalanche hazard elevated. 

Summary

Weather Forecast

Today's weather will bring a mix of sun and cloud with flurries, freezing levels rising to 1300m, and light to moderate westerly winds. More unsettled weather is forecast for tomorrow, with slightly cooler temp's. The Spring convective flurries are the main story, with brief, intense bursts of snow, followed by warm April sunshine.

Snowpack Summary

Storm snow from the last 2 days totals 20-30cm in the alpine. This has formed a storm slab at tree-line and above, while the new snow is insulating a moist, isothermal snowpack below tree-line. Multiple crusts exist in the upper snowpack at treeline & below. Cornices are large in the alpine and if they fail, they will likely trigger deeper layers.

Avalanche Summary

There was limited natural avalanche activity observed yesterday, due to poor visibility and slightly cooler temp's. Glide cracks below tree-line continue to grow and should not be trusted, especially with no solid refreeze overnight. A field team observed a glide crack failure 2 days ago from a SE aspect at around 1300m.

Confidence

Due to the number and quality of field observations

Problems

Storm Slabs

An icon showing Storm Slabs
20-30 cm of heavy snow with moderate winds have formed storm slabs that need time to bond to the underlying moist snow surface. If triggered, these 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.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Loose Wet

An icon showing Loose Wet
There was little to no refreeze last night below tree-line. The new snow overnight will insulate the moist upper snowpack at low elevations. Sunny periods today will stress it and 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.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

2 - 3

Cornices

An icon showing 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, South East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Apr 3rd, 2017 8:00AM