Avalanche Forecast

Issued: Nov 25th, 2016 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is below threshold. Known problems include Wind Slabs and Loose Dry.

tim haggarty, Parks Canada

Banff Yoho Kootenay.

Some welcome new snow has arrived but the strong winds it has come with have quickly developed windslabs in alpine and treeline areas.

Summary

Weather Forecast

Another shot of snow may clip the forecast area tonight as a low passes with amounts in the 5 to 15cm range. Winds will spike again from the SW before everything settles down near the end of the day . Cooling with diminishing winds looks to be in the cards through to Monday.Â

Snowpack Summary

15 to 30 cm of new storm snow has arrived with gusty West winds in the past 24hrs. Below this 15-30 cm of recent snow on top of a supportive (5-10cm) crust found everywhere except on high N slopes.Â The bond to the crust seems strong in most places and the crust generally sits over a strong base for now.

Avalanche Summary

Easy skier triggering in the Sunshine Backcountry today at and above treeline including windslabs have that developed since the weekend, and fresh windslabs formed with the new snow. Natural loose dry activity was seen all day in steeper lee areas along highway 93 some of which may have involved small slabs.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

Widespread new slabs were forming today in a widespread manor. These added to the previous slabs that were local to ridgecrests and all of these were sensitive to skier traffic. Incoming snow amounts and winds should continue to develop these slabs.

Be careful with wind loaded pockets while approaching and climbing ice routes.Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Dry

New snow driven by the wind was spilling down steep lee features today. Some of these sluffs gained considerable mass in confined features making them serious threats to ice climbers and potential triggers for developing windslabs.

Be very cautious with gully features.The new snow will require several days to settle and stabilize.

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

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 2

Valid until: Nov 26th, 2016 4:00PM