Avalanche Forecast

Issued: Jan 9th, 2013 8:13AM

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

mike.koppang, Alberta Parks

Kananaskis.

Warm temps, strong to extreme SW winds and an additional 20cm of new snow overnight is producing widespread storm slabs in open terrain. Conservative terrain choices are a must at this time. A avalanche cycle is ongoing at this time.

Summary

Confidence

Fair - Due to limited field observations on Wednesday

Weather Forecast

Snowfall amounts, winds and temperatures are all expected to fall as a high pressure system begins to push into the region bringing with it cooler air. Expect temperatures to begin to fall overnight and into the day on Thursday. Daytime highs on Thursday are expected to be in the -15C range with light winds out of the north.

Avalanche Summary

No new observations on Wednesday but conditions were obscured for most of the day.

Snowpack Summary

An additional 20cm of new snow over the past 24hrs with strong SW winds. Widespread storm slab development in Alpine terrain and in all open areas at treeline. 35-40cm of recent storm snow can now be expected throughout the forecast region. The 0106 Surface hoar/facet interface is down 40-50cm and extensive cracking was being observed on this layer on Tuesday. The 1106 rain crust at the base of the snowpack should be in skiers minds as there is a potential for avalanches to step down to this interface. Cornices were growing quickly on Wednesday with the warm temps, new snow and strong winds.

Problems

Storm Slabs

35cm of recent storm snow with strong to extreme W and NW winds have created touchy storm slabs. Now is not the time to be in big terrain. This snow is on a surface hoar layer up to approx 2200m and a facet layer above this.

Avoid open slopes with any steepness over 30 degrees.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Avoid freshly wind loaded features.>Avoid lee and cross-loaded terrain near ridge crests.>

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 5

Cornices

Recent warm temps, new snow and strong winds have created widespread cornice development in Alpine terrain. These cornices are touchy and prone to failure so give them a wide berth.

Pay attention to overhead hazards like cornices.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 4

Loose Dry

Steep terrain has recently produced loose dry avalanches up to size 1.5. These dry avalanches may produce larger storm slab avalanches on underlying slopes so be sure to minimize your exposure to overhead hazard.

Be very cautious with gully features.>Choose ice climbs that are not exposed to avalanches from above.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Valid until: Jan 10th, 2013 2:00PM