Avalanche Forecast

Issued: Feb 22nd, 2014 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Persistent Slabs and Wind 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 as morning temperatures will be frigid.

Summary

Weather Forecast

Sunday into Monday will be mostly dry and cold into the minus twenties overnight. Winds will be light from North. Sun will hopefully help by bringing warmer afternoon temperatures.

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.

Confidence

Problems

Persistent Slabs

The persistent slab overlies 2 main weaknesses that will not go away anytime soon. A decomposing surface hoar-surface facet layer 30cm down and thick layer of basal facets-depth hoar. Its spatial variability makes it difficult to predict.

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

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Wind Slabs

Carefully evaluate ridgetop transitions where winds have buffed the surface into a slab. It rests on the suspect surface hoar-surface 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

Valid until: Feb 23rd, 2014 4:00PM