Avalanche Forecast

Issued: Mar 31st, 2012 4:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Forecasts are calling for up to 20cm of snow overnight with strong SW winds and warm temperatures. This will keep the hazard elevated. Storm slabs will become increasingly sensitive with the new load. Cautious route finding is recommended.

Summary

Confidence

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

Weather Forecast

Freezing levels are expected to rise through the early evening before cooling off Sunday morning. Another 20 to 25cm of new snow could fall by morning, with a chance of rain at lower elevations. Winds are expected to be strong from the west, and temperatures will be slightly cooler on sunday. A brief sunny break is possible Sunday morning after the snow storm.

Avalanche Summary

No new avalanches were observed today, but visibility was very limited.

Snowpack Summary

New snow amounts were variable across the forecast area with 10 to 15cm falling at treeline overnight. With the warm temperatures the snowpack is settling rapidly. In the alpine and wind prone areas at treeline soft slabs continue to form. These slabs are sensitive to human triggering where they lie on previously formed crusts. The February surface hoar is still in the back of our minds and is triggerable by heavy loads such as cornices.

Problems

Storm Slabs

Storm slabs up to 40cm deep are present on lee features in the alpine and wind exposed areas at treeline. These slabs are sensitive to human triggering, especially where they sit on buried crusts. Convex and unsupported terrain are areas of concern.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

The February surface hoar is buried 120-150cm at treeline. This interface has been strengthening and becoming harder to trigger, but shallow snowpack areas are still a concern. Cornices or smaller avalanches could step down to this layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 6

Valid until: Apr 1st, 2012 9:00AM