Avalanche Forecast

Issued: Mar 11th, 2015 4:20PM

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

Grant Statham, Parks Canada

Banff Yoho Kootenay.

Warm temperatures in the valley bottoms near Banff have not made it up into the Continental Divide area, and the snowpack has remains solid. Windslabs appear to be building in high elevation areas, and climbers should avoid south facing gullies.

Summary

Weather Forecast

Westerly flow continues with a gradual falling of freezing levels over the main ranges on Thursday. 0-5 cm of snow is expected overnight on Wed, and by Thursday we expect cloud cover and strong alpine winds to keep the higher elevations cool. Valley bottom temperatures will reach +9 in Banff on Thursday.

Snowpack Summary

There is a wide range of conditions from east to west at this time. Eastern areas (Banff) are subject to the warm temperatures which are effecting the snowpack on S and W aspects. Further east the temperatures have remained cool enough that treeline and alpine snowpacks have remained solid. We expect this pattern to continue for several more days.

Avalanche Summary

Another report of a small windslab triggered by skiers on Mt. Cathedral two days ago. This makes for several small windslabs being triggered in isolated areas this week, which is not a huge trend but certainty notable.

Confidence

Problems

Loose Wet

The warm temperatures will create wet sluffs and rockfall on south facing slopes and gullies at and below treeline. Ice climbers should avoid this terrain, and instead search for north facing climbs where the cold temperatures will keep things solid.

Plan to be off big slopes before the temperatures rises and the snowpack deteriorates.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

The lower half of the snowpack is weak due to the presence of basal facets and depth hoar. This layer has been dormant lately but may waken up with the warm temperatures. Avoid steep, open, rocky slopes with a shallow snowpack.

Travel conditions are difficult at lower elevations and in the trees.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Mar 12th, 2015 4:00PM