Forecast strong - extreme winds on Wednesday are driving the alpine danger to HIGH. It is a good time to stick to simple terrain.
Summary
Confidence
Moderate - Wind speed and direction is uncertain on Wednesday
Weather Forecast
A surface ridge sets up on Wednesday over the Interior keeping things mostly cloudy and dry. Ridgetop winds will blow strong and steady through Wednesday then start to back off Thursday night through the weekend. Wednesday: Mostly cloudy. Snow 5-10 cm with alpine temperatures -12 and southwest winds 20-65 km/h.Thursday: Cloudy with snow amounts 5-10 cm. Alpine temperatures -11 and ridgetop winds 25 gusting to 70 km/hr.Friday: A mix of sun and cloud with alpine temperatures -13 and ridgetop winds light from the southeast.
Avalanche Summary
No new avalanche activity was reported on Tuesday. I suspect a natural avalanche cycle occurred, however; the stormy conditions may have prevented people from getting out, or even being able to see alpine areas and/ or start zones. Forecast ridgetop winds are 60-90 km/hr and steady though Wednesday which will likely initiate another natural avalanche cycle.
Snowpack Summary
50-70 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 old surfaces. 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 the snowpack adjusts to the new load.
swerner,
Avalanche Canada
