Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
Banff Yoho Kootenay.
http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=19299&oPark=100092Tricky conditions continue at upper elevations despite cooler temperatures. Watch for solar heating when the sun comes out. Be patient and stick to moderate angled terrain with low consequences, it will take time for the snowpack to heal.
Weather Forecast
Light NW winds, tree line temperatures staying below freezing, no new precipitation, and a mix of sun and clouds is the forecast for the next few days. Watch for the effects of solar heating on steep south aspects when the sun comes out.
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
No new avalanches observed on Sunday. Lots of natural activity up to size 3.5 with wide propagations in the past 48 hrs. Most of these were triggered by wind loading accompanied by solar heating. There have also been notable skier triggered avalanches which stepped down to the basal weak layers. See here for photos of recent events.
Confidence
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.