Avalanche Forecast

Issued: Apr 13th, 2015 4:00PM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Wind Slabs and Cornices.

grant statham, Parks Canada

Banff Yoho Kootenay.

Back to winter for a few days . . . dry slab avalanche conditions exist at treeline and above. For those who have been hitting big lines recently, be aware that conditions have changed and fresh windslabs exist in many areas up high.

Summary

Weather Forecast

A cold front will cross the region on Tuesday, bringing strong winds, 5-10 cm of snow and falling temperatures.Â Expect treeline temperatures to reach -7, and up high it could hit as low as -15. Cold fronts are short and intense, so behind this the air mass will stabilize and clear. Wed, Thurs and Fri could be very nice days.

Snowpack Summary

20-30 cm of recent storm snow has been blown into windslabs in many areas at treeline and above. Although the cloud cover has kept the sun effect to a minimum, these windslabs are expected to be a problem in leeward areas for a few days. This overlies crusts in most areas, which appear to be providing some strength over the deep facet layers.

Avalanche Summary

Some windslab activity up to size 2 observed in alpine areas over the last 24-hours.

Confidence

Problems

Wind Slabs

Strong winds have redistributed the recent 20-30 cm of snow that has fallen. Pockets of soft snow exist, but heads up for fresh windslabs in high alpine areas and near ridgecrests. Give the couloirs a day or two to settle and sluff.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

There have been many reports of cornice chunks falling off of ridge crests which may be big enough a load to trigger an avalanche on the basal facets, or be enough mass to be a hazard themselves.

Stay well back from cornices.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 14th, 2015 4:00PM