Avalanche Forecast

Issued: Dec 26th, 2012 4:00PM

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

A.L. Horton, Parks Canada

Jasper.

We are starting to see the thin snowpack weaken from the prolonged facetting conditions we have been experiencing.

Summary

Weather Forecast

Temperatures are slowly moderating and should be quite pleasant by the end of the week. Winds remain light and no precipitation is expected

Snowpack Summary

Facetting has weakened the snowpack in shallow areas. The snowpack remains strong where the depth is greater than 1 m. A variable soft slab on open slopes tree line that and up is degrading ski quality. Thicker hard slab immediately below ridge lines in the alpine on NW aspects has been buried by recent snowfalls.

Avalanche Summary

A few small slab avalanches to size 1.5 have been observed on steep shallow slopes around tree line on NE aspects. Small loose snow avalanches have been observed today on steep shallow south facing slopes below tree line.

Confidence

Due to the number and quality of field observations

Problems

Deep Persistent Slabs

Small natural slab avalanches to size 1.5 are starting to pull out to ground on the basal facets in thin snowpack areas. Faceting continues to weaken the snowpack on thicker slopes. Triggering is most likely to happen in thin snowpack areas.

Carefully evaluate and use caution around thin snowpack areas.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

The wind slab condition that formed following last week's wind event has been buried by recent snows. These wind slabs are most likely found immediate to ridge lines on open slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 27th, 2012 4:00PM