Avalanche Forecast

Issued: Mar 21st, 2013 9:15AM

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

mike.koppang, Alberta Parks

Kananaskis.

The snowpack is slow to improve right now. The crusts we are dealing with will take some time to sort themselves out. Be hesitant to trust the crust interfaces. This is not the time to jump into big terrain. MM

Summary

Confidence

Good

Weather Forecast

The convective snow is predicted to continue for Friday. Amounts are uncertain, but with the wind factored in, the new load could be considerable. Winds will be light in the alpine and shifting to a northerly flow for a brief time. Freezing level will remain at the surface height.

Avalanche Summary

There were no new observations today. However the snowpack still remains touchy with the added load of new snow. The natural cycle may resume with additional load.

Snowpack Summary

10cm of convective snow has fallen in the last 24hrs. This new snow is settling quickly with the warm temps. The bond with the older HST is slow to develop. Ski cutting had small, results in steep terrain. This is expected to improve quickly. The variety of crusts remains the major concern. The bond with the newer storm snow and/or storm slabs is suspect and seems to vary. A brief, natural cycle of in the last 48hrs adds to the suspicion.

Problems

Storm Slabs

Storm slabs averaging 40cm thick are present on all aspects in the Alpine and open areas at Treeline. From TL to mid ALP, the slabs sit on top of the crust and are touchy to human triggering.

Assess start zones carefully and use safe travel techniques.>Avoid cross loaded features.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Persistent Slabs

Several crust layers are found in the upper snowpack. These crusts reach as high as 3000m on S aspects and between 22-2400m on other aspects. Carefully evaluate the bond at these interfaces and watch for rapid temperature changes.

Avoid exposure to sun exposed slopes.>Avoid exposure to overhead avalanche terrain, as large avalanches may reach the end of runout zones.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Cornices

Avoid steep slopes below cornices.>

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Mar 22nd, 2013 2:00PM