Avalanche Forecast

Issued: Feb 21st, 2012 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

An additional 10cm of snow and strong NW winds are in the forecast. If more snow falls than is expected, hazard could rise to HIGH. Valentine's layers of surface hoar/facets/sun crust are highly reactive to natural and human triggers. (JM)

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Up to 10cm of new snow possible overnight on Tuesday with continued strong to extreme winds. Winds will shift to NW. Temperatures to be cool.

Avalanche Summary

Few Na slabs up to size 2.0 in ALP on SE, E and NE asp.

Snowpack Summary

Additional 3 cm at TL. Valentine's layers now buried by 25 to 45cm, easily triggerable by ski cutting. Wind affect ALP and TL. CTE(3)(SP) down 25 on surface hoar size 10mm.

Problems

Wind Slabs

Soft slabs are now dominant in lee and cross-loaded terrain in alpine and treeline areas. Open areas below treeline have also been affected. These slabs are very sensitive to human triggering and are failing on the Valentine's layers down 25 to 45cm.

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Loose Dry

Loose unconsolidated surface snow is sluffing in steep terrain and continues to produce avalanches up to size 1.5. Ski cutting is triggering sluffs that could gain mass and/or trigger a slab below.

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Deep Persistent Slabs

Weak facets and depth hoar linger at the base of the snowpack. Thin steep areas are the most likely trigger points. This problem is still a low probability issue, but with high potential consequences.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Feb 22nd, 2012 8:00AM