Avalanche Forecast

Issued: Nov 15th, 2015 8:25AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs, Storm Slabs and Loose Dry.

Parks Canada percy woods, Parks Canada

Recent wind loading of storm snow over the November 11th surface hoar layer requires skiers and riders to have a cautious approach to their route selection today.

Summary

Weather Forecast

Light S winds and another 20cm of snow expected today.  Temperatures will remain close to zero during the day with a cooling trend overnight tonight.  Monday brings a small break between systems with another pulse of precipitation coming Monday night through Tuesday with upwards of 40cm of snow.

Snowpack Summary

20cm snow overnight with light winds will be enough to obscure the wind slabs formed on alpine lee features during Friday's storm.  Yesterday allowed a view of alpine fetch stripped down to bare rock by Friday's strong S-SW winds.  Lee features will be harboring slabs well down slope from ridge lines.  Nov 11 surface hoar resides under the slabs. 

Avalanche Summary

Limited observations of a few avalanches along the highway corridor out of steep lee slope terrain. 

Confidence

Due to the number of field observations

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs have formed on alpine lee slopes. These slabs reach further down slope due to strong S-SW winds on Friday. Slabs sit on top of the Nov 11 surface hoar layer, widespread above 1800m. These slabs will be sensitive to triggering.
Watch for whumpfing, hollow sounds, and shooting cracks.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Storm Slabs

An icon showing Storm Slabs
Temperatures just below zero continue to promote settlement of storm snow. Upwards of 70cm of storm snow have fallen since Thursday afternoon. Given the right terrain feature this storm slab could be susceptible to triggered by skiers and boarders.
The new snow will require several days to settle and stabilize.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Loose Dry

An icon showing Loose Dry
Surface sloughing into confined steep gully features may produce enough moving snow to be a hazard to skiers and riders. Be cautious of what terrain you are committing to.
Use caution above cliffs where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 16th, 2015 8:00AM