Regions
Kootenay Boundary.
If more than 20cm new snow arrives with wind on Saturday, bump the danger ratings up by one at all elevations.
Confidence
Fair - Intensity of incoming weather is uncertain
Weather Forecast
Overnight Friday: 5-10 cm new snow with strong SW winds and treeline temperatures around -6C.Saturday: Snow, picking up in intensity in the afternoon. 5-10 cm. Treeline temperatures around -4C. Winds gusting to 60 km/h from the southwest.Sunday: 5-10 cm snow expected overnight Saturday, but during the day on Sunday, things should be mostly dry. Moderate SW winds. Treeline temperatures around -6C.Monday: 5 cm new snow. Moderate SE winds. Treeline temperatures falling to -10C.
Avalanche Summary
On Friday, only loose snow avalanches to size 1 were observed.On Thursday, machine-triggered avalanches were reported running at the base of the most recent storm snow down 20 to 50 cm. Explosive testing produced avalanche up to size 2.5 in the storm snow at elevations around 2000 m.On Wednesday, natural and skier-triggered avalanches up to size 2.0 were reported to be releasing down 30-50 cms in the storm snow.
Snowpack Summary
Around 110 cm new snow has fallen in the last week. The storm slab has been very easy to trigger in areas where the wind stiffened the slab a bit. In most places the slab is still relatively unconsolidated and soft and it is not propagating far. Expect heavy sluffing in steep terrain. The well settled mid-pack has not been showing shears in snow profile tests.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.