Avalanche Forecast

Issued: Nov 6th, 2019 4:22PM

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

Mark Herbison, Parks Canada

Banff Yoho Kootenay.

Recent wind and persistent slab activity in the region over the past few days.

It's still early, ski and ride with care as rocks, stumps and open creeks would be an easy way to end the season.

Thanks to those who are posting on the MIN.

Summary

Weather Forecast

A mix of sun and cloud for Thursday, light to moderate SW winds, daytime high of -2 with no snow in the forecast. Friday will see cloud and light flurries throughout the day.

Snowpack Summary

20-30 cm in the past 3 days in the Bow Summit area, accompanied by strong winds produced wind affected snow in the alpine. Treeline snow depths range from 60-70 cm, and up to 110 cm in lee areas. Today's field trip found the October crust present in some areas and has been the failure plane in recent skier involvements.

Avalanche Summary

Numerous dry loose avalanches in the region today from steep rocky terrain triggered by solar input. Received a third hand report of a full burial in the Observation Peak area on Sunday afternoon, no injuries. Size 1.0 skier remote also occurred in the same area yesterday. Explosive work on Mt. Stephan triggered windslabs sz 2-2.5.

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

Strong winds and the new snow has created pockets of wind slab treeline and above. Watch for wind affected areas in steep terrain while climbing or skiing.

Be careful with wind loaded pockets, especially in steep confined alpine terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

A thin crust exists in the lower snowpack and has been the failure plane for a few skier accidental avalanches in the past 4 days to size 2.0.

Convex features and steep unsupported slopes will be most prone to triggering.
Remote triggering is possible, watch out for adjacent slopes.