As of Wednesday, April 17
Approximately 40 cm of new snow fell in the high alpine terrain during the storm-cycle ending last Monday morning. Temperatures reached 0 degrees on Saturday at 2,100 m then plummeted rapidly that night. Winds during the storm-cycle were moderate to strong from the SE and SW, with gusts reaching 150 km/h at the mountaintops on Sunday night.
Loading was extremely variable due to the strong winds. Windward aspects were scoured down to the crust. More leeward slopes had some pockets of wind slab of up to 50 cm in depth that were reacting easily to the weight of a skier or boarder.
Cornice activity throughout this period was significant with large natural releases observed in some areas.
In other areas of the province this storm cycle resulted in a big avalanche cycle, with a number of size 4.0 avalanches reported to have occurred in various Interior mountain ranges. There were also reports of several large isothermal avalanches below treeline in the Duffey Lake area that had stepped down to an old buried weakness. A sign of things to come?
A tragic accident just outside of Fortress Mountain should serve as a reminder to those who spend considerable time taking hits with their friends in exposed terrain, such as that in Flute. Two separate groups of snowboarders were involved in this incident. One group was merrily taking hits under a large slide-path. The other group entered from the top and triggered a large avalanche that swept away the boarders on the slope below. This tragedy ended in the death of two of those involved, a third is in the hospital in Calgary.
Choose your terrain carefully! There are lots of areas out there where hits can be had without exposing everyone to this level of danger.
The backcountry avalanche danger is currently rated as MODERATE, but can be expected to increase with exposure to the sun and mild temperatures.
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.
The long-range weather forecast is calling for us to be treated with several days of mild and sunny weather from Thursday to Saturday. A cooler, unstable north-westerly flow may establish itself on Saturday night, and be with us into early next week.