Avalanche Forecast

High -

Friday: Mainly cloudy with isolated flurries and a trace of new snow. Winds light to moderate from the northwest. Freezing level to 500 metres with alpine temperatures to -10.Saturday: Mainly cloudy with isolated flurries and a trace of new snow. Winds light from the west. Freezing level to valley bottom with alpine temperatures of -9.Sunday: A mix of sun and cloud with no new snow. Winds light to moderate from the northeast. Alpine temperatures around -13.

Avalanche observations continue to trickle in from observers getting out into the mountains since this week's storm began. Yesterday's reports include three natural size 2-2.5 avalanches. The largest of these released approximately 50cm deep in the storm snow on a wind-pressed southwest slope. Explosives control and slope cutting continue to yield size 1-1.5 results in the storm snow, with crown depths usually around 20cm in previously controlled terrain but reaching up to 60cm in areas that hold the full depth of storm snow. Avalanche debris has been noted for entraining lots of the loose new snow and running surprisingly far. Continued snowfall and moderate winds over Thursday will promote ongoing slab formation. For the short term, look also for loose dry avalanches to be triggered easily in steep sheltered terrain.

Between 35 and 70cm of new low density snow has fallen over the region since Monday. The highest accumulations have occurred in the Monashees. Observations suggest wind slab formation in the new snow has been less than expected, but wind slab can still be found on lee features in higher elevation terrain where the winds were stronger. In areas sheltered from the wind, the new snow is mostly loose and unconsolidated. 50-100 cm below the surface you'll find the mid-December interface which consists of wind affected snow, faceted (sugary) crystals, and/or surface hoar crystals. Recent tests suggest the the new snow is well bonded to this interface in most areas. However, this layer is still reactive in some snowpack tests and should be investigated before pushing into steeper terrain. Limited observations from the North Columbia region suggest this layer may be especially touchy on the eastern side of the Selkirks. The thick mid-November crust layer typically sits 1-2 m down in the snowpack. This layer is considered dormant at this time but remains an isolated concern that we will likely be tracking through much of the season.