Avalanche Forecast

Issued: Nov 7th, 2019 4:00PM

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.

lisa paulson, Parks Canada

Little Yoho.

After a cold, sunny break in the weather Wednesday, the winds picked up again Thursday as temperatures warmed up. Watch for increased winds, warming, and likely some precipitation to increase avalanche hazard into the weekend.

Summary

Weather Forecast

Following moderate to strong winds and warming temperatures Thursday, further warming and increased winds are expected Friday. Models vary greatly on the amount of snow we can expect over the next three days. Friday's warm temps may lead to rain near treeline and 2 to 10 cm , while cooling through Saturday should favor snowfall up to 10cm.

Snowpack Summary

20-30 cm fell Nov 3 to 5th in the Bow Summit area with strong winds that produced wind affected snow in the alpine. Treeline snow depths range from 60-70 cm, and up to 110 cm in lee areas. The October crust found close to the ground in some areas has been the failure plane in recent skier involvements.

Avalanche Summary

We Received a third-hand report of a full burial in the Observation Peak area on Sunday afternoon. A separate size 1.0 skier remote also occurred in the same area Tuesday. Explosive work Tuesday on Mt. Stephen triggered 3 thin windslabs in the alpine. One of these stepped down to a create a sz 2.5 slab almost as deep as the glacier ice.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Friday

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. The extent of this problem should increase with Friday's winds.

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.