Avalanche Forecast

Issued: Jan 28th, 2019 8:02AM

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

Chris Gooliaff, Parks Canada

Glacier.

Watch for a reactive soft slab below tree-line on unsupported features today. And put on some sunscreen!

Summary

Weather Forecast

Calm and clear, with plenty of sunshine. Alpine high of -8*C, light Northerly winds, and no snow today. More of the same tomorrow, with slightly warmer alpine temps (-6*C) and light winds. A system will start to move into the area by the end of the week, bringing 20-30cm by Friday with warming temp's.

Snowpack Summary

Strong southerly winds have created a variable wind slab in lee and cross-loaded alpine and tree-line features. The Jan 17 persistent weak layer (surface hoar or suncrust) is buried 30-50cm, and is most reactive in sheltered areas below tree-line.

Avalanche Summary

Numerous natural avalanches up to sz 2.5 from steep N and S alpine features (Macdonald and Tupper) were observed in the highway corridor. A cornice failure did produce a sz 3 from Tractor Shed W. Field teams were able to ski cut soft slabs to size 1 on steep, unsupported features below tree-line (Asulkan and Bostock drainages).

Confidence

Problems

Persistent Slabs

The Jan 17th layer is down 30-50cm and consists of surface hoar in sheltered areas and sun crust on steep solar aspects. This layer is most problematic between 1600-1800m, and sensitive to human triggering.

Convex features and steep unsupported slopes will be most prone to triggering.Use caution on open slopes and convex rolls where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

Strong S winds have created variable wind slabs at tree-line and above. The slab varies from soft/skiable to perfect igloo-block building crud. Expect a range of surface conditions if you go up high today.

Use caution in lee and cross-loaded terrain near ridge crests.Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 29th, 2019 8:00AM