Avalanche Forecast
Issued: Feb 23rd, 2012 9:27AM
The alpine rating is Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Forecast snowfall amounts are uncertain on Saturday
Weather Forecast
A low pressure system is moving inland from the coast on Friday. This system is forecast to bring snow and moderate southwest wind to the Kootenay Boundary by afternoon and to the South Rockies region by the early evening. Snowfall amounts are forecast to be about 5 cm for the South Rockies on Friday. Another 10-15 cm for the South Rockies and 15-20 cm in the Lizard Range are expected overnight and during the day on Saturday. Sunday is forecast to be a mixed bag of convective flurries and some sunny periods. The freezing level is expected to rise to about 700 metres on Friday, drop back to valley bottom overnight and then rise to near 1200 metres on Saturday.
Avalanche Summary
We have reports of numerous avalanches up to size 2.5 with crowns about 40-50 cm on N-NE aspects in the Corbin area of the Flathead.
Snowpack Summary
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.
Problems
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 24th, 2012 8:00AM