Avalanche Forecast

Issued: Nov 27th, 2013 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Skiing prospects are not too enticing until we get more snow. Many ice climbs are in and have pounded trails to the base of many popular climbs.

Summary

Weather Forecast

Winds will pick up to moderate SW on Thursday.Â Light snow forecasted for Friday.Â If the forecast is correct, the next substantial snowfall (10-15 cm) is expected on Sunday.

Snowpack Summary

On alpine lee features, the snowpack consists of windslabs over a weak midpack with a very weak base of facets. The Oct 27 crust on N-NE aspects is breaking down, but is still a sliding layer near ground. On average at treeline there is 70 cm of snow, barely blanketing the rocks and stumps.

Avalanche Summary

No new naturals in past few days. Explosive work at Sunshine and Lake Louise still producing size 1.5-2 avalanches on North and West aspects failing on basal facets or the Oct 27 crust. Propagations are not as significant as earlier in the week, but any steep windloaded feature in the Lake Louise area were producing avalanches.

Confidence

Due to the quality of field observations

Problems

Persistent Slabs

The Oct 27 crust or basal facets continue to produce easy failures in field tests and in explosive work around the ski areas. The greatest potential for triggering this layer is on steeper windloaded pockets.

Ski penetrations may be to ground in some areas due to weak and unconsolidated snowpack.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Nov 28th, 2013 4:00PM