Avalanche Forecast

Issued: Jan 18th, 2017 4:00PM

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

a.l. horton, Parks Canada

Jasper.

Be cautious in the new snow. Wind and storm slabs may be easily triggered.

Summary

Weather Forecast

Further 7-10 cm possible until Thursday. Moderate SW winds continuing, easing on Friday. Temperatures will gradually fall into the weekend to seasonal levels.

Snowpack Summary

Recent storm snow (between 10-20 cm) with heavier amounts in the southern forecast area has formed windslab on lee aspects from previous strong to extreme SW alpine winds. Storm slabs may be present on lower elevation slopes. These slabs are sitting on buried wind slabs overlying weak facets from the mid-pack to ground.

Avalanche Summary

No avalanche patrol today. No avalanche observations reported.

Confidence

Due to the number of field observations on Thursday

Problems

Wind Slabs

The interface between the new and old slabs could be touchy.

Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

Storm slabs may be present especially at tree-line. The weight of this may overload the weak facets below.

Use caution in alpine and open treeline lees. Recent snowfall has created storm slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

Concern for new snow overloading the season's weak faceted basal layers.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 19th, 2017 4:00PM