Avalanche Forecast

Issued: Feb 21st, 2013 5:25PM

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

jon stuart-smith, Parks Canada

Waterton Lakes.

A storm on Friday afternoon could bring up to 25cm of new snow by Saturday. This will come with strong southwest winds and will build on already growing windslabs. Avalanche danger will increase for the next few days depending on the storm intensity.

Summary

Weather Forecast

A significant storm is forecast to hit the area last in the afternoon on Friday. This could bring up to 25mm of precipitation. Winds are forecast to be strong from the West or SW throughout the storm. The storm should be over by midday on Saturday with skies clearing and cooler temperatures.

Snowpack Summary

Winds picked up last night and were strong SW throughout the day. Up to 10 cm of new snow at ridgetop in the last 48hrs. This is building windslab on N and E lee slopes. The storm snow from the weekend has settled and seems to be bonding well but with sun crust and old wind slabs underneath this, the bond may not be good on all aspects.

Avalanche Summary

No new avalanche activity was observed on Thursday.

Confidence

Timing of incoming weather systems is uncertain on Friday

Problems

Wind Slabs

Slabs are continuing to form in exposed areas with SW winds. These are growing in size and thickness with continued precipitation. If the snow arrives Friday as forecast these slabs could build to 1m thick on north and east lee slopes in the alpine.

Stay off recent wind loaded areas until the slope has had a chance to stabilize.Avoid avalanche terrain during periods of heavy loading from new snow and wind.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 24th, 2013 4:00PM