As of Wednesday, Dec. 17
An intense system deposited 50cm of new snow during the 18 hour period ending on Tuesday evening. The snowfall was accompanied by Southerly winds gusting to 100 km/h during most of the day. Significant windslab development was observed to have occurred throughout this period with some fat pockets forming to the lee of some terrain features, up to 1m in depth at treeline elevations.
Easy shears were observed within the storm snow layers throughout the day on Tuesday. The surface slab was reactive to both explosive and ski testing on some slopes, while remaining non-reactive on others. Some natural avalanche activity was also observed to have occurred. By Wednesday morning the storm snow layers had appeared to begin to tighten-in, but were still reactive to explosive and ski testing in the Alpine.
One potential buried weakness of note is a layer of surface hoar that formed earlier this month. This layer remains intact below treeline elevations, and now lies approximately 1m below the surface. We may begin to see activity within this layer in some isolated areas with the additional loading that is now on it. Be particularly cautious around any steep drainages, gullies, or terrain traps below treeline.
Be wary of any hollow feeling snow surfaces in the backcountry. Due to the high winds throughout the storm, many of the avalanche starting zones are loaded lower down than usual, with the upper part of the start zone having been scoured. You may have already passed the point of commitment by the time you realize that you are standing on a slab tighter than drum.
As of Wednesday Dec. 17 th , The Backcountry Avalanche Danger is rated as CONSIDERABLE.
Conditions may vary and can change rapidly. Check for the most current conditions before heading out into the backcountry. Daily updates for the areas adjacent to Whistler-Blackcomb are available at 604-938-7676, or at www.whistler-blackcomb.com/weather, where there is also a link to the CAA public avalanche bulletin, or call 1-800-667-1105.