Avalanche Forecast

Issued: Feb 23rd, 2014 4:00PM

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

garth lemke, Parks Canada

Jasper.

Human triggered avalanches remain possible on specific slopes such as steep convex shaped wind-loaded features. Skiing is good in sheltered locations. Watch for frostbite! It does not feel like it is warming up much even in the sun.

Summary

Weather Forecast

Next few days will be dry, sunny, and cold overnight temperatures into the low -20's. Expect some warming in the afternoons with the sun's energy. Winds will be light from Northwest shifting Southwest Tuesday and Wednesday. Maybe some flurries on Thursday.

Snowpack Summary

Approximately 30cm of windslab or softslab, depending on aspect and elevation, is overtop a combo facet-decomposing surface hoar layer. This is most prevalent treeline into the lower alpine elevations. Below tree line there is a supportive yet shallow mid-pack over facets-depth hoar. Alpine is a variety of layers but generally all well bridged.

Avalanche Summary

No new natural avalanches were observed or reported. Visibility was excellent.

Confidence

Problems

Wind Slabs

Carefully evaluate ridgetop transitions where winds have buffed the surface into a slab. It rests on the suspect surface hoar-facet layer 30cm down. Valley bottom winds have created slab pockets in exposed locations below treeline.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

The persistent slab is intermixed with 2 main weaknesses that will not go away anytime soon, the decomposing surface hoar-facet layer and thick layer of basal facets-depth hoar. Its spatial variability makes it difficult to predict.

Assess start zones carefully and use safe travel techniques.Caution around convexities or areas with a thin or variable snowpack.

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Feb 24th, 2014 4:00PM