Avalanche Forecast
Regions: South Columbia.
Confidence
Fair - Intensity of incoming weather is uncertain on Tuesday
Weather Forecast
Overnight and Tuesday: A warm front is moving across the region tonight and a trailing cold front should move through the region in the morning. Expect 15-20 mm by early morning and another 10-15 mm by noon. Strong Westerly winds are forecast during the storm that will ease to moderate with the passing of the cold front. Alpine temperatures should be -9.0 and the freezing level may rise to 900 metres during the storm.Wednesday: There is a weak ridge between systems that should bring very light precipitation, light Westerly winds and temperatures down to -10.0 in the alpine.Thursday: The next frontal system is looking weak at this time. Expect light precipitation and SW winds. Check back tomorrow for an update.
Avalanche Summary
Some very soft slabs were released with explosives control up to size 1.5 and heavy sluffing reported from ski cutting.
Snowpack Summary
The wind may have already started to transport the light surface snow. If not, there should be wind effect by morning, and a lot of snow available for transport into wind slabs. There is widespread sluffing in the new snow in steep unsupported terrain, but no reports of slab avalanche failures in the storm snow. The late November surface hoar is now buried more than a metre deep and close to 150 cms in some of the snowier areas. This layer has mostly been found between 1700-2000 metres in elevation. There have not been any new reports of avalanches sliding on this layer. The early November rain crust is deeply buried. There was one report of a size 3.0 avalanche that released naturally on this layer in the southern Selkirks. I think we need to keep this problem on the front page through another storm cycle, and see how it reacts to more loading and rapid temperature changes.
Avalanche Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 5
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 2 - 6
Deep Persistent Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood: Unlikely
Expected Size: 4 - 7