Avalanche Forecast

Issued: Dec 13th, 2012 4:10PM

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

A.L. Horton, Parks Canada

Jasper.

Although the avalanche hazard is Moderate, now is not the time to jump into the big lines.

Summary

Weather Forecast

Light snow and light NW winds can be expected on Friday.Â Expect seasonal temperatures.

Snowpack Summary

There is great variation in depth and location of the wind slabs that continues to build and harden from continued moderate to strong SW winds.Â Theses slabs have bonded well.Â In windswept areas in the alpine and at tree line, the November rain crust has been exposed along with dirt and rocks.Â Cornices are well developed.

Avalanche Summary

No new avalanches have been observed or reported since the end the cycle that ended on Monday.Â In that cycle, slab avalanches to size 3 were observed on NE aspects at alpine and tree line elevations, several stepped down to the basal facet layer.Â Large cornice failure triggered large avalanches on the basal facet layer as well.

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

Pockets of wind slabs that vary in hardness are present on all open lee slopes. No new avalanches have been observed and field tests show that these slabs have bonded well in most locations.

Avoid unsupported slopes.Choose well supported terrain without convexities.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Deep Persistent Slabs

Large loads such as slab avalanches and large cornice failures have triggered this weakness on SE to NE aspects in the alpine.

Avoid steep slopes below cornices.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Dec 14th, 2012 4:00PM