Avalanche Forecast

Issued: Nov 25th, 2016 8:16AM

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

percy woods, Parks Canada

Glacier.

Storm snow and moderate to strong S winds are forming fresh windslab, the avalanche danger is increasing.

Summary

Weather Forecast

10cm of snow expected today with an additional 20cm forecast to land by Saturday evening. Alpine winds SW 30km/h gusting to 80km/h today with S winds in the 25-45km/h range on Saturday. A soft slab forming forecast.

Snowpack Summary

From Bruins ridge at 2330m yesterday, East aspect we had a whole block RB 4 down 55cm about 5cm above the November crust. Also of interest was a 5cm graupel layer down 11cm giving sudden collapse results. The graupel layer may be sensitive today with the additional loading and soft slab formation from overnight storm snow and strong south winds.

Avalanche Summary

A natural avalanche cycle occurred overnight along the MacDonald avalanche paths up to size 3. Yesterday a size 2 avalanche was observed in Cheops 4 reaching the top of the fan. Southerly winds are increasing into the strong range this morning. Avalanche danger is increasing.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

Pockets of windslab may be found in the immediate lee of alpine and treeline features.

Use caution in lee areas. Recent wind loading have created wind slabs.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

80cm of storm snow has fallen in the past week. Settling is resulting in slab formation over the Nov 13 crust. Field tests on the interface and a stellar layer just above indicate the slab may have a poor bond and may be triggered by light loads.

Carefully evaluate terrain features by digging and testing on adjacent, safe slopes. Choose regroup spots carefully.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Nov 26th, 2016 8:00AM