Avalanche Forecast

Issued: Mar 24th, 2013 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Solar radiation is a real concern. South and West aspects will become more sensitive to triggering in the afternoon and cornices should be treated with caution. Be aware of overhead terrain.

Summary

Confidence

Good

Weather Forecast

Sunny skies with light W to NW winds for the next couple of days. Temperatures in the alpine will range between -12 and -10 on Monday. No precipitation is expected.

Avalanche Summary

Isolated sluffing in steep terrain, including one small Nc release that pulverized in the cliff bands below. One size 2.0 slab avalanche on a steep E aspect at 2600m occurred in the past 24hrs. Minor snowballing on steep S and W aspects in the afternoon.

Snowpack Summary

Crusts are melting and re-forming on S, SW and W aspects with the diurnal temperature swings, getting slightly thicker each day. On N and E aspects between 5 and 20cm of recent snow overlies a variety of buried slabs. These slabs are a concern in steep, unsupported terrain. Snowpack is generally weak in sheltered areas below treeline.

Problems

Wind Slabs

A variety of wind slabs have been created over the last week. These slabs are now hidden under 5 to 20cm of recent snow, but remain sensitive to human triggering in steep and unsupported terrain.

Choose well supported terrain without convexities.>Avoid lee and cross-loaded terrain near ridge crests.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Cornices

Cornice failures continue to be a theme, with several failures triggering slab avalanches in recent days. Be aware of overhead exposure especially during times of intense solar radiation.

Pay attention to overhead hazards like cornices.>Cornices become weak with daytime heating, so travel early on exposed slopes.>

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Persistent Slabs

A few crust layers are found in the upper snowpack. These crusts reach as high as 3000m on S aspects and 2200m on other aspects. Monitor the location of these layers within the snowpack and assess the bond with layers above.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be aware of thin areas that may propagate to deeper instabilites.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Mar 25th, 2013 2:00PM