Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
Kootenay Boundary.
Sun and warming on Thursday and Friday will increase the likelihood of avalanches. Be particularly cautious on south-facing slopes when it is sunny and avoid exposure to large slopes above you.
Confidence
Moderate - Due to the number and quality of field observations
Weather Forecast
TONIGHT: Mostly clear. Ridge wind light, southeast. Alpine temperature -3. Freezing level 1600 m.THURSDAY: Mostly clear. Ridge wind light, east. Alpine temperature near 0. Freezing level 2200 m.FRIDAY: Mostly sunny, increasing cloud in the afternoon. Rain changing to snow overnight. Precipitation 2-8 mm. Ridge wind light, southwest. Alpine temperature near +1. Freezing level 2300 m.SATURDAY: Cloudy, flurries. Accumulation 5-10 cm. Ridge wind strong, southwest. Alpine temperature near -2. Freezing level 1700 m.
Avalanche Summary
On Tuesday there was a report of a skier-triggered storm slab size 1.5 on a north aspect at treeline north of Rossland that failed on a crust. Read MIN report here.On Monday, loose wet avalanches were triggered naturally and by explosives. They were large (size 2 to 2.5) and on all aspects between 1700 m and 2100 m.
Snowpack Summary
An additional 20 to 35 cm of snow fell Tuesday into Wednesday, for storm snow totals of 35 to 60 cm since Monday morning. The snow fell on a melt-freeze crust produced from rain and warm temperatures on Sunday. Numerous other melt-freeze crusts exist in the upper snowpack from rain, sun, and warming during the spring season. The mid and lower snowpack are generally well-settled and strong.At lower elevations below treeline, a spring snowpack exists.
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 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.