Avalanche Forecast

Issued: Feb 16th, 2013 4:00PM

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

a.l. horton, Parks Canada

Jasper.

Finally some snow!!! Good weather on Sunday and Monday will be tempting. Resist the urge to jump into big lines until the new snow has had a chance to settle.

Summary

Weather Forecast

Snow will end late on Sunday morning with up to 20 cm possible. Skies will clear in the afternoon, Northerly winds will drop and temperatures will fall. Family Day Monday will be mostly clear with light winds and seasonable temperatures

Snowpack Summary

Soft windslab are developing on Easterly alpine and treeline slopes with continuing snow and moderate West winds. These new slabs are sitting on hard slab and sastrugi. The now buried hard slab is bridging weak basal facets. 10 cm+ new snow is sitting on sun crusts and facets below treeline.

Avalanche Summary

No avalanche observations due to snow and low clouds on Saturday.

Confidence

Forecast snowfall amounts are uncertain on Sunday

Problems

Storm Slabs

Up to 20 cm of new snow will fall by Sunday afternoon. Moderate W to NW winds will be building slab conditions. These new storm slabs are sitting on smooth hard slab. The bonding between these layers is uncertain.

Stay off recent wind loaded areas until the slope has had a chance to stabilize.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

There will be increasing load on the persistent slabs now buried by 15-20 cm on new snow. There is a greater possibility that storm snow avalanches may be enough to trigger the persistent slab layer deeper in the snowpack.

The recent snow may now be hiding windslabs that were easily visible before the snow fell.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1 - 3

Valid until: Feb 17th, 2013 4:00PM