Avalanche Forecast

Issued: Dec 24th, 2016 4:00PM

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

max darrah, Parks Canada

Jasper.

Scoured alpine terrain may push eager skiers to loaded gullies and lee terrain where the possibility of triggering windslabs exists. The Jasper Visitor Safety team wishes everybody a safe and happy holiday season!

Summary

Weather Forecast

The next light snowfall is expected to begin on Boxing Day, with light scattered flurries to wrap up 2016. The light Northerly flow will change to moderate Southwest winds with the next pulse of precipitation. Temperatures expected to rise from -20 to -12 with the new snow bringing in the new year.

Snowpack Summary

10 cm of fresh snow may be found in sheltered areas. Previous strong winds have built slabs in lee features, cross loaded gullies and added to the size of cornices. Weak layers include; buried surface hoar (Dec 11) in sheltered NE aspects around treeline (2100-2300m) and the Nov 12 crust approximately 30cm from the ground.

Avalanche Summary

No new reports or observations in the past 24 hours on road patrols in the Maligne Valley and Columbia Icefield Area.

Confidence

Problems

Wind Slabs

Strong winds have created a mosaic of snow depths across the landscape. These slabs will vary greatly in their triggering sensitivity requiring each slope to be evaluated carefully.

Watch for whumpfing, hollow sounds, and shooting cracks.Be aware of the potential for wide propagations due to the presence of hard windslabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The depth of this crust is now highly variable, and may be as deep as 1m in lee areas that have received significant loading due to strong SW winds. Careful evaluation of this interface is essential.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Carefully evaluate and use caution around thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 25th, 2016 4:00PM