Avalanche Forecast

Issued: Apr 5th, 2017 3:14PM

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

mike.koppang, Alberta Parks

Kananaskis.

A snowy week is forecast so expect windslabs to build as the snow arrives. Rain/Sun are two things that can quickly deteriorate stability out there right now so keep an eye on these meteorological factors!

Summary

Confidence

Moderate -

Weather Forecast

A snowy week is headed our way it looks like.Â Over the next few days up to 40cm of snow is expected to fall with strong winds out of the SW in alpine areas.Â Freezing levels on Thursday are forecast to be around 2300m then dropping throughout the week.Â When the sun does come out it packs an intense punch and stability on solar aspects can deteriorate quickly.Â If the forecast freezing levels do come true, we may even see some rain at lower elevations.Â Watch the sun and freezing levels on your trips!

Avalanche Summary

No new natural avalanche activity was noted on Wednesday.

Snowpack Summary

A clear and cold night brought a good surface freeze to the snowpack overnight, but that changed quickly on steep solar aspects where snow was moist by late morning. Solar aspects have a variety of buried crusts, whereas polar aspects above 2100m have an average of 20cm of dry snow sitting on a variety of previous surfaces. Wind slabs are present everywhere in the Alpine except in sheltered features. Not much natural avalanche activity has occurred with these wind slabs, but many areas like ripe for human-triggering. As previously reported the mid-pack remains dense and strong, but the basal layers are very weak consisting of anywhere between 50 and 100cm of facets sitting on the ground. Forecasters still have low confidence for traveling in large Alpine terrain, unless there has been widespread previous avalanching.

Problems

Wind Slabs

Not much natural avalanche activity with these wind slabs yet, but human-triggering is more likely in convex and unsupported features. These slabs seem confined to the Alpine.

Avoid freshly wind loaded features.Use caution in lee areas. Recent wind loading has created wind slabs.Avoid cross loaded slopes at or above treeline.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

We know it sounds like a broken record, but this deep layer is still a threat in any avalanche terrain that has not yet had extensive previous avalanching. While there is a lower probability of triggering, the consequences are high.

Pay attention to overhead hazards like cornices which could easily trigger deep slabs.Be wary of slopes that did not previously avalanche.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

2 - 4

Loose Wet

If/when the sun comes out, stability can quickly decrease on solar aspects. Rain at lower elevations may also trigger this problem. Pay attention to the quality of freeze overnight.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 6th, 2017 2:00PM