Avalanche Forecast

Issued: Mar 19th, 2014 8:33AM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Heavy snowfall warning for the region could bring 20cm with NW winds by the end of Thursday. A very conservative approach to terrain is strongly recommended over the next couple of days.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Snowy conditions are expected Thursday with as much as 20cm of new snow in the next 24hrs. Winds will become moderate from the NW with alpine temperatures climbing to -9 degrees. A further 5 to 10cm is possible on Friday.

Avalanche Summary

A few new naturally triggered slabs were observed today in steep Alpine and Treeline terrain. These slabs occurred on E and SE aspects and were of variable depth. Sizes ranged from 1.5 to 2.0 with one of the slides running to 3/4 fan.

Snowpack Summary

Recent storm snow is settling. Sun crusts are found on steep solar aspects at all elevations. Wind slab development continues in the Alpine and Treeline with persistent Westerly winds. The Feb 10th layer remains reactive and is buried between 80 and 110cm.

Problems

Persistent Slabs

This persistent weak layer is buried 70 to 110cm in Alpine and Treeline areas and is sensitive to human triggering. The additional snow load on Thursday will make this layer more reactive and could trigger a natural avalanche cycle.

Avoid convexities or areas with a thin or variable snowpack.>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

Wind Slabs

Snow and wind on Thursday will add to already existing wind slabs in Alpine and Treeline areas. Avalanche activity related to this problem was observed Wednesday, and more slides are expected on Thusday. Reverse wind loading is also possible.

Avoid freshly wind loaded features.>Avoid cross loaded features.>Avoid convexities or areas with a thin or variable snowpack.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 4

Loose Dry

Watch for sluffing in steep terrain on all aspects at all elevations.

Be cautious of sluffing in steep terrain.>Watch for terrain traps where small amounts of snow will acumulate into deep deposits.>Sluffs may trigger deeper instabilities.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 20th, 2014 2:00PM