Regions
Kootenay Boundary.
Localized convective snow flurries could lead to variable avalanche hazard throughout the region on Monday.
Confidence
Fair - Forecast snowfall amounts are uncertain
Weather Forecast
Synopsis: Unsettled conditions dominate early this week resulting in scattered convective precipitation, sunny breaks, and gusty winds. Monday: Mostly cloudy with periods of snow (around 3-8 cm). The freezing level is around 1700-1800 m and ridge winds are moderate from the west. Tuesday: Sun and cloud with periods of snow. The freezing level is near 1500 m and winds are light from the SW. Wednesday: Sunny breaks. The freezing level is around 1600-1800 m and winds might increase to moderate from the W.
Avalanche Summary
On Saturday there were reports of a few loose wet slides up to size 1.5. Numerous natural and rider triggered avalanches to size 2 were reported Friday as moist storm snow slid on the robust mid-March crust.
Snowpack Summary
An average of 30-50 cm of moist new snow now sits on the mid-March crust, which is 10-15 cm thick. Wind loaded features may have as much as 60 cm on the crust. Recent reports suggest that the overlying snow is bonding well to the crust. During the heat of the afternoon, the snow surface has been reported to be moist or wet at all elevations on solar aspects and up to 2000m on north aspects. At many elevations, melt-freeze cycles are occurring with a weak surface crust forming overnight and then breaking down during the afternoon. Older deeply buried persistent weak layers still exist in the snowpack but are no longer expected to be reactive.
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 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.