Avalanche Forecast

Issued: Mar 6th, 2012 6:18PM

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

jon stuart-smith, Parks Canada

Waterton Lakes.

The weekend brought up to 60cm of new snow. Forecast are calling for strong NW winds Wed/Thur which will build new wind slabs. Warming on Thur/Fri will reduce stability, especially below treeline. Watch for moist snow over crusts at lower elevations.

Summary

Problems

Storm Slabs

Temperature changes and strong winds during the weekend storm created weak layers down 20 and 50cm. Stiffening of the slab over the next few days with wind and warm temps could make triggering these slab easier.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

Previous wind slabs are now buried 15cm and still could be triggered by skiers. NW winds forecast for Wed will be building windslabs outside of normal locations. With all the new snow from the weekend, these slabs will grow quickly.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

Suncrusts now down70 to 80cm can be found on steep southerly aspects. Watch for these in thin or wind scoured snowpack areas. Probability of triggering is diminishing however consequence continues to grow.

Aspects: North, North East.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Mar 9th, 2012 4:00PM