Avalanche Forecast

Issued: Feb 26th, 2013 8:28AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Persistent Slabs.

burke.duncan, Alberta Parks

Kananaskis.

Windslabs remain the greatest concern with persistent westerly winds in the moderate range. As the week progresses and forecast warming occurs it may become necessary to pay close attention to the effects of daytime heating on solar aspects.

Summary

Confidence

Fair - Freezing levels are uncertain on Friday

Weather Forecast

Temperatures at 3000m cool in the -15 deg range until midday Thursday when they begin to climb to the -5 deg range.Â A chance of a quick pulse of new snow on Wednesday night but amounts of only 2-4cm likely.Â Moderate westerly winds increasing to strong/extreme by Wednesday night into Thursday and after that the winds really go to town with the warmer air and are forecast to top over 100 km/h by Friday.

Avalanche Summary

Several loose dry sluffs to Size 1.5 from steeper lee aspects with small cornice failures the trigger for some

Snowpack Summary

Storm snow from past few days slowly adding up with 10-15cm low density snow in sheltered areas.Â Several test profiles done today with consistent results - CTM14-16 (PC) down @15+ cm on top of old windslabs and CTH24 (SP) down 30-35cm on Jan hardslab interface.

Problems

Wind Slabs

Soft slabs at treeline and have become more sensitive to human triggering, especially in lee and cross-loaded features just below ridgeline. Alpine areas are scoured with areas of hard slab and soft slab. Increased cornice development taking place.

Be cautious as you transition into wind affected terrain.>Avoid steep slopes below cornices.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Persistent Slabs

Buried wind slabs (originally formed in late January) are still are concern in steep features in the alpine and at treeline. These slabs are found down 30 to 60cm in the snowpack and are likely more trigger-able from shallow snowpack areas.

Avoid convexities or areas with a thin or variable snowpack.>Avoid shallow snowpack areas where triggering is more likely.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Feb 27th, 2013 2:00PM