Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
Banff Yoho Kootenay.
Natural activity is tapering and the new snow and bluebird weather makes everything looks so tempting. Do the smart thing and resist temptation to step into bigger terrain as conditions are still prime for human triggering!
Weather Forecast
A ridge of high pressure is sitting above us. We can expect pleasant spring weather on Tues and Wed with light alpine winds, cool overnight temperatures (-10/ -15) and minimal solar effect on the snowpack despite the sunny skies. Winds should pick up to moderate from the West on Wed PM and we may see some light snow (5-10cm's) overnight Wed.
Snowpack Summary
Some wind effect in open areas above tree line. Temperature crust present below 1800m. 60-70cm of well settled snow from recent storms and warm temperatures sits over weak facets and depth hoar at the bottom of the snowpack. A snow pit done at 2350m near Cirque Peak on Saturday demonstrates the snowpack layering common in the forecast region.
Avalanche Summary
Another skier accidental: size 2 in the Sunshine Backcountry on Sunday. One new avalanche reported on Monday: a size 2.5 naturally triggered slab on a SW aspect at 2500m in the Mt. Assiniboine area. Limited observations today, however, we are just coming out of a natural avalanche cycle on Saturday, and conditions are still touchy.
Confidence
The weather pattern is stable
Problems
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.