We are dealing with a complex avalanche scenario. There is uncertainty in how buried weak layers will adjust to the warm temperatures. Conservative decision making is still recommended.
Summary
Confidence
Fair
Weather Forecast
Freezing levels are forecast to remain high through Monday (up to 2600m) before gradually falling over Tuesday and returning to valley bottom by Wednesday. Winds will remain moderate from the south west with a possibility of showers and/or flurries Monday and Tuesday.
Avalanche Summary
Observations have been limited by reports indicate a wide spread avalanche cycle ongoing through the weekend. We are now moving into a complex avalanche scenario where touchy conditions are likely to persist. A snowpack with several critical avalanche layers has seen incremental loading in the form of new snow and more recently rain. Two recent avalanche cycles have produced increasingly large avalanches primarily on the mid-January surface hoar layer. While the region will see only light precipitation through the coming forecast period it will fall as rain on all but the highest peaks. I anticipate that natural avalanches will remain possible and human triggered avalanche likely as the upper snowpack adjusts to the warm temperatures. Warming temperatures will also make cornices more likely to collapse, which in turn could be sufficient to trigger a deep slab avalanche. I would be wary of overhead hazard. At lower elevations I suspect there is the potential for loose wet and wet slab avalanches.
Snowpack Summary
Warm temperatures and/or rain are encouraging the recent snowfall to rapidly settle into a widespread soft slab. Moderate to strong southwest winds have created wind slabs in lee features at treeline and above. A weak layer of surface hoar buried mid-January lies buried between 50 and 85 cm below the surface may sit above a crust, particularly on south-facing slopes. This layer has been responsible for the majority of the recent avalanche activity and I suspect that we will see it continue to produce avalanches as the snowpack adjusts to the recent load and continued warm temperatures. The mid-December surface hoar/crust layer is now buried anywhere from 60 to 120cm below the surface and continues to be a concern. While it appears to be gaining strength I suspect that a large enough load in the right spot may still be able to trigger this layer and I'd continue to treat this layer with respect and suspicion, particularly on open slopes at treeline.
esharp,
Avalanche Canada
