Avalanche Forecast

Issued: Apr 7th, 2018 4:00PM

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

garth lemke, Parks Canada

Jasper.

Good skiing is found in the region with continued winter like conditions.

Summary

Weather Forecast

Sunday will be sun and isolated flurries, trace of snow, high of -2, light West winds and 2100m freezing level. Monday will be flurries, trace snow, -5 to -3, and light gusting moderate West winds. Tuesday will be flurries, 5-10cm of snow, -6 to -1, and light gusting strong SW winds.

Snowpack Summary

Snow from March 30th and light amounts since has been blown in to an isolated wind slab up to 30cm thick. This has added to the previous slab sitting on a sun-crust on solar aspects and facets on North aspects - buried as deep as 60cm. The snowpack is generally facetted and weak underneath the slab particularly in shallow areas.

Avalanche Summary

Read and share conditions in the region by visiting Avalanche Canada's Mountain Information NetworkCornice failures reported early last week have triggered persistent slabs below ridge-tops.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Wind Slabs

Windslabs have developed in exposed alpine and treeline locations 10-30cm thick. They are generally well bonded but pockets of instability exist. Some propagations of 50-100m were noted last week.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution on open slopes and convex rolls

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Persistent slabs sit on facets on North aspects and a hard melt-freeze crust on solar aspects. Use a cautious approach in open terrain and assess the bond at these interfaces before committing to a slope.

Watch for signs of instability such as whumpfing, or cracking.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Cornices

Cornices continue to grow with fresh snow and wind. Several failures were noted in the past week with some triggering a slab below. Potential for cornice failures increases with sun and warmth.

Minimize exposure during periods of loading from new snow and wind.Give cornices a wide berth when travelling on or below ridges.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 8th, 2018 4:00PM