Regions
Kootenay Boundary.
Confidence
Fair - Timing or intensity of solar radiation is uncertain on Tuesday
Weather Forecast
Sunday night: Light snow. Light W winds. Alpine temperature near -9.Monday: Light snow (5-10 cm). Light W winds, gusting to strong NW. Alpine temperature near -5.Tuesday: No snow. Light to moderate SW winds. Alpine temperature near -3.Wednesday: Snow (10-15 cm). Moderate S winds. Alpine temperatures near -4.
Avalanche Summary
A few small sluffs were observed on Saturday as new snow began to show a poor bond to the crust below. I’d expect there was a lot more of this type of activity on Sunday.
Snowpack Summary
Around 30 cm of dry new snow arrived overnight Saturday/Sunday, which landed on a hard refrozen crust in most places (the exception possibly being very high elevation terrain). Strong NW winds are likely to have shifted this new snow into touchy wind slabs in the lee of terrain breaks. In non-wind affected steep terrain, sluffs may be running easily.Deeper in the snowpack, weak interfaces of surface hoar and/or crusts have become much less likely to be triggered now that they are capped by a supportive crust. However, until more information is gathered about the distribution and resilience of the crust, I’d keep these deeper weaknesses in the back of my mind, especially where they might be stressed by a very heavy load or triggered from a place where the crust above is not as strong (e.g. high elevation terrain or thin spots around rocks).
Problems
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.
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.