Hi all,

We just wrapped up and exciting ski touring week out of Mallard lodge in the Canadian Rockies West of Jasper National Park. We enjoyed some excellent powder ski-touring however, we had limited terrain choices as the avalanche conditions were really touchy.

Weather conditions were mixed & generally warmer than average for mid February, daytime high ranged from -15.0C to +2.0C throughout the week at the Lodge (1960m). Winds were the dominant factor for most of the week. Moderate to Strong ridge top winds from the Southwest created wind slabs in lee slopes and wind effect in exposed alpine areas. A pacific storm starting February 14th brought up to 25cm of new low density snow to the area. This combined with lighter winds significantly improved the skiing quality. Throughout the week, we skied between 2600m and 1600m on Southwest, North and East aspects. We were much more confident in deeper snowpack areas and skied supported terrain up to 35 degrees. Overhead hazard was a significant factor in route selection.

The snowpack in this area is very weak and touchy. There was an average of 165cm at treeline which was supportive to skiing at this elevation and above. Some below treeline areas were less supportive. A classic Rockies snowpack with variable distribution including deep pockets in lee slopes and shallow exposed areas. The mid and lower snowpack was very soft, a weak facet layers along with harder crusts near the ground were present. Snow pack test produced moderate to hard resistant shears down 25cm on the Feb 14th layer and down 40-50cm on the Feb 9th layers. Tests on the December 18th facet layer down 60-120cm produced variable results; mod to hard sudden shears in shallow snowpack areas and no results in deeper snowpack areas.

We notice some natural avalanche activity in the storm slab to size 2.5 out of steep alpine terrain however, there was surprisingly very little natural activity on the deep persistent slab. That said we remotely triggered several size 2 to 2.5 avalanches from 20m to 200m away with propagation width reaching 500m. Fracture line ranged from 30 to 200cm deep! All of these were accompanied with earth shattering whumpfs predominantly in steeper rocky rolls in north facing between 2250m and 2100m. Needless to say, it wasn’t just the skiing that was exciting!

All in all, a good week of skiing in the Rockies with great avalanche dynamics visuals and learning's. The deep persistent slab deserve respect and monitoring, potential for large and deep human triggered avalanche exists.

Play safe out there!

Cheers,

David Lussier
acmg mountain guide
www.summitmountainguides.com