Avalanche Forecast

Issued: Feb 19th, 2015 8:00AM

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

danyelle magnan, Parks Canada

Glacier.

Summary

Weather Forecast

A brief and weak weather system will bring a bit of snow, but the ridge will rebuild on Friday. Today expect clouds and flurries, with gusty west winds at ridgetop. We may receive up to 4cm by Friday morning. Friday will be similar; cloudy with flurries. On Sat the ridge will bring a mix of sun and cloud and cooler temps.

Snowpack Summary

Very challenging travel and ski conditions exist below 1900m. Above 1700m 5-15cm of snow sits on the Feb 14 crust, which exists to ~2200m. Steep solar aspects have a sun crust. Persistent weak layers between 1m to 1.5m are stubborn to trigger but give sudden test results in isolated areas. The mid and lower snowpack is well settled.

Avalanche Summary

No new avalanches were observed yesterday. Recent avalanches were solar triggered. On the weekend, impressive deep slab avalanches occurred. A size 3.5 from the col between Clarke Peak and Mt Swanzy was likely triggered by cornice fall and ran on glacier ice. In the Asulkan Valley, a size 3.0 from Mt Pollux ran on the Nov 9 crust/to ground.

Confidence

Problems

Cornices

Impressive avalanches have been triggered recently by cornices falling on slopes, some failing to deep basal layers. Minimize exposure to slopes with cornices and use caution while traveling along ridges.

Pay attention to overhead hazards like cornices.Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 4

Persistent Slabs

Persistent weak layers down ~1 to 1.5m will likely need a large load such as a cornice failure to be triggered. A light load, like you, may be able to trigger them from shallow areas. When triggered these layers continue to propagate widely.

Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 4

Valid until: Feb 20th, 2015 8:00AM