Avalanche Forecast

Issued: Nov 26th, 2018 4:00PM

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

ian jackson, Parks Canada

Banff Yoho Kootenay.

No recent natural avalanches, but a report of a large rockfall in the popular Puzzle Peak area gives skiers something new to think about! Strong winds and incoming light precip will slowly raise the danger over the next few days

Summary

Weather Forecast

A warm wet storm is approaching the coast, but we won't get much in the Rockies. Winds have already picked up to strong to extreme from the south, but will ease as it starts to snow on Tuesday. Expect light snow on Tuesday (2-10 cms) and mild temps. Wednesday should see another 2-5 cms with moderate SW winds

Snowpack Summary

Moderate to strong south winds are creating windslabs in the alpine. These sit over sun crust on steep south slopes or surface hoar on sheltered N aspects. The Oct 26 crust is found ~10-30 cm above the ground with large facets growing both above and below it. The snowpack averages 40-85 cm at 2200m across the region and is weakening as it facets

Avalanche Summary

The October 26 crust and facet layer is still occasionally reactive. One explosive controlled size 2 failing on the Oct 26 crust was reported in the alpine at Lake Louise on Sunday. Ski cutting produced a thin new snow slab on a steep alpine S aspect at Sunshine Village on Sunday. No new natural avalanche activity observed on Monday

Confidence

Intensity of incoming weather systems is uncertain on Wednesday

Problems

Deep Persistent Slabs

Occasional reports continue of skier remote and explosive triggered slabs on the October 26 crust and facet layer. Avoid steep terrain where a stiffer, more cohesive slab exists over these weak, faceted crystals near the base of the snowpack.

If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.Whumpfing is direct evidence of a buried instability.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 27th, 2018 4:00PM