Avalanche Forecast

Issued: Jan 11th, 2013 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs.

chris gooliaff, Parks Canada

Banff Yoho Kootenay.

The new snow that fell over the week needs time to settle. The sunny skies may entice people to charge hard, but give it some time to stabilize. The sunny skies and possible inversion will heat up sunny, alpine slopes, causing avalanches. Heads up!

Summary

Weather Forecast

A high pressure ridge has plunked itself on top of the region, creating mainly clear skies and light to moderate winds from the NW. We don't expect any snow in the next few days, but an inversion may set up Saturday and Sunday, with temp's being up to 10 degrees warmer in the alpine than the valleys.

Snowpack Summary

Up to 50 cm of settled storm snow and mod SW winds created storm slabs that are sitting on a weak layer of surface hoar and faceted crystals. On steeper S aspects, sun crusts were buried. The winds died down at the end of the storm, so wind slabs formed during the storm may be hidden by innocent-looking powder. The mid-pack in most areas is strong.

Avalanche Summary

A widespread natural avalanche cycle occurred during the storm on Wednesday. Since then, natural activity has decreased. Given that there has been a significant new load of snow on a variety of weak surfaces, skier triggering is still possible. I'd recommend easing into terrain this weekend, watching for surface slabs.

Confidence

Problems

Storm Slabs

Up to 50 cm of settled storm snow and moderate SW winds have created storm slabs on a weak facet layer. Whumphing and cracking was observed in the field, so skier triggering is still possible. Tree-line elevations seemed to be the most touchy.

Be cautious as you transition into wind affected terrain.Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Jan 12th, 2013 4:00PM