Avalanche Forecast

Issued: Feb 6th, 2015 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

New snow, warm temps and rapid loading due to wind is triggerring a natural avalanche cycle. Rain fell up to 2000m so some snowpack areas below this elevation may be rain saturated.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain on Saturday

Weather Forecast

Another 10-15cm of snow is forecast to fall overnight before the storm tapers off. Freezing levels are expected to drop to 1600m overnight and be around 1800m on Saturday. Winds will increase at higher elevations to strong out of the SW.

Avalanche Summary

Visibility was limited throughout the day on Friday but a few new slides were observed and reported into the forecasting office. Of note was a sz 2.5 Na in the Buller Mountain control zone. This run was skied a few days ago and today slid to ground down 1.5m in some places. This was on a NE aspect at 2200m in 30-40deg terrain and 70m wide.

Snowpack Summary

Warm temperatures, new snow and moderate to strong SW winds have created widespread storm slabs at Alpine and treeline elevations. These slabs are failing within the recent storm snow and down 40cm on the 0131 crust. The freezing level on friday hovered around 2000m. In a few locations were have seen the 0106 basal crust wake up with the new load creating larger avalanches.

Problems

Storm Slabs

Warm temps, moderate SW winds and new snow are creating ideal conditions for developing storm slabs.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Avoid freshly wind loaded features.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

Weak facetted crystal above and below the crusts both in Jan (down 30-40cm) and Dec (down 40-50cm) are becomming more triggerable with the new snow loads.

Avoid cross loaded slopes at or above treeline.>Carefully evaluate and use caution around thin snowpack areas.>Avoid unsupported slopes.>

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

Recent avalanche activity on the November rain crust indicates that avalanches may step down to this interface and cause a large avalanche.

Be aware of thin areas that may propogate to deeper instabilites.>Be aware of the potential for large, deep avalanches.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

3 - 5

Valid until: Feb 7th, 2015 2:00PM