More snow, strong winds and warmer temperatures are driving the danger ratings. Its a good time to stick to simple non-avalanche terrain.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Tuesday
Weather Forecast
The Interior is under a strong zonal flow that is responsible for pushing out the cold air and bringing in the snow! We can expect to see an additional two - three systems move across the region through the forecast period.Tuesday: Snow 10-20 cm with freezing levels rising to 900 m. Alpine temperatures -10 and ridgetop winds West 35-45 km/hr.Wednesday: Snow 5-10 cm with freezing levels dropping to valley bottom. Alpine temperatures -11 and ridgetop winds SW 50 km/hr.Thursday: Snow 5 cm with alpine temperatures -14. Ridgetop winds South 15-35 km/h.
Avalanche Summary
Several natural storm slabs up to size 2 were reported on Monday, however; I suspect a widespread natural avalanche cycle occurred as some areas received up to 50 cm!! Given the weather forecast we can expect to see avalanche activity continue Tuesday.
Snowpack Summary
20-50 cm of new storm snow sits above a plethora of old snow surfaces including stiff wind affected snow, faceted (sugary) crystals and surface hoar crystals that formed in locations sheltered from the wind. The new storm snow will likely have a poor bond to these. The mid-November crust is buried down 70-150 cm and produces variable results in snowpack tests. Moderate results may be more likely in shallower snowpack areas, and deeper snowpack areas may be more likely to show no results on this layer. Tracking and monitoring this potentially weak interface is crucial especially as we move forward into this stormy period where the snowpack will see more load.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.