Avalanche Forecast

Issued: Nov 9th, 2018 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Looks to be a fairly nice weekend. Check to see if the Oct 26 layer is present on slopes you are using, and if there is a slab on top that could be of concern.

Summary

Weather Forecast

The weekend looks mainly dry with 3000m temperatures in the -12 to -15C range, and valley bottom temperatures topping out at -5C. Winds will decrease Saturday and remain NW.

Snowpack Summary

In the alpine, 20-50cm with variable wind effect sits on the Oct.26th temperature crust, can be found mainly on shaded aspects in the alpine,and is a few cm thick above weak facets. Total snowpack depths are 60-120cm+ in the alpine, tapering dramatically at treeline and below threshold for avalanches below treeline.

Avalanche Summary

No new avalanches reported today. Over the previous few days there have been numerous avalanches on the Oct 26 interface. This includes skier remote triggered avalanches to size 2 along hwy 93N, and remote triggered avalanches to size 2.5 from explosives at the Lake Louise ski hill that were 250m and 350m away from the initial explosive.

Confidence

Problems

Deep Persistent Slabs

The Oct.26 crust and facets are causing lots of whumpfing and have produced a few skier and remote triggered avalanches. It has been found up to 2800m on shady alpine aspects, with some limited evidence to support its existence on solar aspects.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2.5

Wind Slabs

Recent winds have caused smaller wind slab formation in lees of alpine ridges which could be triggered over the next day or two.

Aspects: North, North East, East, North West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Nov 10th, 2018 4:00PM