Avalanche Forecast

Issued: Mar 14th, 2016 6:05PM

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

grant statham, Parks Canada

Banff Yoho Kootenay.

We're doing avalanche control on Tuesday on Mt. Bosworth, Mt. Field, Mt. Dennis and Mt. Whymper. Please no access to these areas.

Summary

Weather Forecast

A similar weather pattern for the next few days - on Tuesday expect overcast skies with light snow through the day, probablyÂ not accumulating more than 3-5cm. Temperatures will remain cool from -2 to -10 and relatively light winds.Â Excellent weather for quality tree skiing!

Snowpack Summary

30-50 cm of snow sits above crusts to 1800m and all solar slopes. Recent S-SW winds with strong gusts have formed slabs in lee areas that bond poorly to these crusts. Across the region the snowpack is highly variable, but in most areas the snowpack is just over 150cm deep and generally weak facets near the basal layers.

Avalanche Summary

Close call today. In the Simpson area (deeper snowpack) we were on a ridge crest and triggered a large cornice. This cornice dropped onto the slope below and triggered a 400m wide size 3 avalanche that ran for approximately 900m. The slab failed on a buried suncrust, and ranged from 50-100cm deep. Watch out for buried crusts with accumulated load!

Confidence

Problems

Deep Persistent Slabs

The mid-pack facets remain weak, especially in thin or rocky areas. Avoid steep or unsupported terrain, and watch for signs of instability such as whumpfing and cracking.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Persistent Slabs

Now that the sun is higher in the sky, buried suncrust becomes more of a problem. Presently there are several crusts buried on S and W aspects, all with 50-100 cm overlying them. Dig, look and test these layers before committing to any solar slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Wind Slabs

Over the past seven days we're received 45 cm of light snow, so it won't take much wind to create small pockets of drifted windslabs in areas on the leeward side of ridge crests at higher elevations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 15th, 2016 4:00PM