Regions
Kootenay Boundary.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain on Wednesday
Weather Forecast
Overnight and Tuesday: The Low pressure system is forecast to move out of the region this evening. Strong Southwesterly winds should slow down to moderate Westerly as the Low exits to the East. Flurries are expected to continue overnight without much accumulation.Wednesday: A weak upper ridge should move into the Southern Interior by Tuesday evening and continue to provide dry conditions on Wednesday. Light Westerly winds should become strong Southwesterly as the next system moves in from the Coast during the evening.Thursday: Strong Southwest winds and heavy precipitation are forecast. Timing is uncertain.
Avalanche Summary
Explosives control at Kootenay Pass created soft slab avalanches up to size 1.5 in the morning. Poor visibility and travel conditions have limited observations.
Snowpack Summary
Another 20 cms of snow on Monday brings the recent storm snow up to about 50 cms. The storm snow initially fell with very light winds and settled into an unconsolidated or very soft slab. On Monday the strong Southwest winds started transporting that snow and stiffening the slab. Expect very touchy soft slab conditions in sheltered terrain and stiff wind slab conditions on North thru East aspects. The storm snow may not bond well to old surfaces at lower elevations. The Rossland Range has a buried surface hoar layer at treeline and below that may become reactive with added load of this storm snow.
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.