South Rockies

Fair - Forecast snowfall amounts are uncertain on Saturday

Moderate to heavy snowfall on Friday is expected to continue overnight into Saturday morning. Expect 10-15 cm in the West of the region and about 5-10 cm in the East by Saturday noon. The freezing level should remain at about 800 metres during the storm and then drop down to valley bottoms by Saturday evening. Winds are forecast to be moderate to strong from the South until about midnight and then ease a bit and clock to the west for the morning hours of Saturday. Expect to see some convective flurries on Sunday as a ridge of high pressure slides in behind the storm bringing light northerly winds by late in the day. There may be some sunny breaks on Sunday, and mostly clear skies and cooler temperatures for Monday.

Natural avalanches have become less frequent, but human triggered avalanches continue to release from light additional loads. Skier controlled avalanches up to size 2.0 were reported today to be easy to initiate in some areas and a bit more stubborn in others. The forecast new snow and wind may cause new windslabs that may overload the PWL in some areas.

Gusty wind has transported snow into windslabs at all elevations. In southern and western parts of the region, 40-50 cm of recent snow sits of a highly reactive weak layer of crusts, surface hoar and facets. At 1950 metres elevation we have some snow pack test results that show that the 40 cm slab of snow above the February 8th weak layer is sliding with easy to moderate forces applied and it is propagating widely with either sudden planar or sudden collapse characteristics. The slab is reported to be less consolidated on northerly aspects than it is on southerly aspects. In areas further north, less snow has fallen on this interface--in the northern Elk Valley for instance, only around 15-20 cm lies above this interface. In lower snow areas, avalanche activity will likely lag behind higher snow areas, except for areas which have seen significant wind transport. In general, the mid-pack is quite strong in most locations. However, lingering concern remains for basal facets, particularly in shallower snowpack areas with steep, rocky start zones.