Avalanche Forecast

Fair - Forecast snowfall amounts are uncertain on Wednesday

Overview: A zonal weather pattern will continue to bring moisture to the South Columbia Mountains, particularly for Wednesday and Thursday. Expect higher freezing levels and greater accumulations further south within the region.Tuesday night: Up to 20cm of snow / Moderate to strong southwesterly winds / Freezing level at about 1000mWednesday: 15-20cm of snow falling late in the day and overnight / Moderate to strong westerly winds / Freezing level rising from surface to about 1500m with the arrival of the system Thursday: About 15cm of snow / Moderate westerly winds / Freezing level at about 1500mFriday: Flurries / Moderate northwest winds / Freezing level at about 1800m

Explosives control on Sunday produced avalanches to size 2 which ran on the February 10 persistent weak layer. On the same day a helicopter remotely triggered a size 1.5 slab on the same interface.Since then, natural and human triggered storm slab avalanches to size 2 occurred in wind loaded pockets in the alpine and at treeline.

Up to 35cm of storm snow overlies surface hoar in sheltered areas, a sun crust on solar aspects and wind slabs in exposed terrain. On lee slopes these accumulations have been pushed into much deeper deposits by generally moderate southwest winds. Forecast snowfall, wind and warming will add to the reactivity and destructive potential of this developing storm slab.There is ongoing concern for a mix of weak surfaces which were buried on February 10th. This persistent interface lies between 80 and 130cm below the surface, and includes surface hoar, well developed facets and a mix of hard surfaces which remain widespread at all aspects and elevations. Although avalanche activity at this interface has generally tapered-off, large and destructive human triggered avalanches are still possible in isolated terrain.For the most part, the mid and lower snowpack are strong and well consolidated.