Avalanche Forecast

Issued: Jan 14th, 2018 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

This is a good time to be conservative in your terrain choices and minimize exposure to avalanche terrain. The chances of human triggered avalanches will increase as temperatures rise.

Summary

Weather Forecast

A temperature inversion will continue through the forecast region, with alpine temperatures above freezing through Monday into Tuesday. Skies will remain relatively clear and winds in the light to moderate range. Expect unusually strong solar outputs for this time of the year on South and West aspects Monday and Tuesday afternoon.

Snowpack Summary

Warm alpine temperatures and clear skies moistening the upper snowpack on steep S-W aspects. There is 30-50 cm over the Dec.15 persistent weak layer of facets and surface hoar. This Dec 15th layer is becoming reactive to skiers at treeline and above and producing easy to moderate snowpack test results. Below this is a heavily faceted snowpack.

Avalanche Summary

The Dec 15 interface continues to show signs of reactivity, reports throughout the forecast region note significant whumphs and cracking from skier traffic at treeline and above. Avalanche activity from this problem was observed along the sunshine road releasing a size 2 slab.

Confidence

Problems

Wind Slabs

Wind slabs have formed in the alpine and near ridge crests at treeline. Watch for the changing feel of the snow under your feet and be wary of areas with denser surface snow over weaker snow.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

This layer continues to linger in forecasters minds. Easy test results and report of significant whumps and cracks show the potential for this to be a dangerous problem. Be very careful with this layer and travel conservatively.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.Choose conservative lines and watch for clues of instability.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Jan 15th, 2018 4:00PM