Avalanche Forecast

Issued: Mar 19th, 2015 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

We are on the verge of better ski quality given the current forecast. Watch locally for new wind slabs in the alpine sitting over harder surfaces beneath. SH

Summary

Weather Forecast

The Lake Louise region will start to see snow to the tune of 10cm on Friday with freezing levels to 2200m. The Banff/Sunshine region may only see 5cm. A storm pushing through the region for the weekend may bring 20-25cm along the divide with light to moderate westerly winds.

Snowpack Summary

Recent strong wind has created hard slabs on the snow surface in the alpine. 5-10cm of new snow fell on the Wapta today in the alpine. New snow Friday with wind will increase the wind slab thicknesses. At and below treeline expect to find a mix of facets and crusts. As ghastly as that combination sounds, generally it is well bonded.

Avalanche Summary

No new avalanche observations today.

Confidence

Forecast snowfall amounts are uncertain on Saturday

Problems

Wind Slabs

Watch for wind slab development over the next 24 hours in the lees of alpine features. These will be sensitive to triggering in isolated features such as ridge crests and will continue to be through the weekend.

The recent snow may now be hiding windslabs that were easily visible before the snow fell.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: All aspects.

Elevations: Alpine.

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 be more sensitive with forecasted new snow load, especially in thin areas.

Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 20th, 2015 4:00PM