Avalanche Forecast
Regions: South Columbia.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
THURSDAY: Flurries, accumulation 5-10cm / Wind light south / Alpine temperature -10Â FRIDAY: Isolated flurries, accumulation 5-10cm / Wind light to moderate southeast / Alpine temperature -10Â SATURDAY: Mix of sun and cloud / Wind light west / Alpine temperature -11
Avalanche Summary
A report from just northeast of Nakusp on Monday shows a size 2 persistent slab release on a north aspect at 1800 metres. Another report from Sunday showed a skier-triggered Size 1 persistent slab releasing from a north aspect at 2200 metres.
Snowpack Summary
Last week's storm brought 50-80 cm of new snow to the region. Predominantly northerly winds have since redistributed this storm snow into wind slabs at higher elevations. In sheltered areas cold temperatures have inhibited slab formation. The storm snow lies over a variety of old surfaces, including surface hoar (weak, feather-like crystals), sun crust, and sugary facets. The bond at this old snow interface is of critical importance in areas where the overlying snow has consolidated into a slab. The most concerning areas are those that saw pronounced surface hoar development before the storm, such as sheltered areas at and below treeline or sheltered northerly aspects in the alpine. Recent snowpack tests show wide ranging reactivity on this weak layer but suggest that it may be most reactive on northerly aspects.A rain crust that formed in late November is now buried 90-120cm deep. Recent evidence from adjacent regions suggests it may be reactive in steep, variably loaded terrain features in the alpine.
Avalanche Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 3