Avalanche Forecast

Issued: Mar 13th, 2015 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

New snow and intense wind will form windslabs. The hazard will increase throughout the day Saturday as the load increases.

Summary

Weather Forecast

Poor overnight recovery is expected for Saturday morning below treeline. Then, an intense weather system is expected to pulse through, bringing rain to low elevations and 10-15cm of snow to the alpine. Strong winds accompanying this system will create poorly bonded windslabs on lee (North and East) aspects. Sunday will be cooler.

Snowpack Summary

The snowpack is generally crusty or isothermal in valley bottoms, depending on temperature and exposure to sun. In the alpine windcrusts, windslabs and suncrusts predominate. In high shallow areas, lingering weaknesses are still common.

Avalanche Summary

No new avalanches observed or reported today.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

Snow and high winds Saturday will create poorly bonded windslabs.

Use caution in lee areas. Recent wind loading have created wind slabs.Caution in lee and cross-loaded terrain near ridge crests.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Wet

Watch for early morning rain and isothermal conditions on low elevation ice climbs.

Travel conditions are difficult at lower elevations and in the trees.Plan to be off big slopes before the temperatures rises and the snowpack deteriorates.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

The lower half of the snowpack is weak due to the presence of basal facets and depth hoar. This layer has been dormant lately but may waken up with the warm temperatures , rain, or in shallow areas.

Avoid thin, rocky or sparsely-treed slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 14th, 2015 4:00PM