Natural avalanches possible, human triggered probable.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural and human triggered avalanches likely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
Banff Yoho Kootenay.
No expected freeze overnight and rain below 2400m on Friday will keep the hazard elevated until freezing levels drop. SH
Weather Forecast
Rain starting tonight and freezing levels to 2400m overnight. Alpine temperatures will stay around zero overnight.Expect a mix of rain and snow Friday up to treeline with snow at upper elevations(up to 20cm). No freeze is expected overnight. Models are calling for 30-40cm at upper elevations with freezing levels lowering by the end of the weekend.
Snowpack Summary
A weak freeze broke down quickly this morning as temperatures rose into the double digits in the alpine early in the day. Thin snowpack areas are isothermal at all elevations and aspects. Basal facets and depth hoar are waking up as the heat penetrated the snowpack.
Avalanche Summary
A widespread natural cycle to size 3.5 has been occurring over the last 24 hours. Lots of loose wet avalanches, and many slides initiating in thin areas and running to ground. One very large avalanche in the Bryant Creek area crossed 3 alpine bowls showing that the weak basal layer is very reactive during these warm conditions.
Confidence
Freezing levels are uncertain
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.