As of Wednesday, Feb. 7
We have received dribs and drabs of new snow during the past week. Moderate to strong winds from just about every direction were a big factor in the snow distribution. The northerlies eventually prevailed with the onset of the clearing and cooling on Feb. 5.
With each new snowfall, the storm snow seemed to generally settle in and to form a good bond to the previous layer within 24 hours. There continued to be some activity in pockets of windslab.
As the snow stability continued to improve and backcountry enthusiasts grew more confident with testing the steeper lines, the avalanche gods suddenly turned on the switch again. On Feb. 4, we began to see large natural activity happening. Most was triggered by cornice fall, and in many cases the failure plane appeared to be the November layer of facets. Ipsoot, Overlord and Decker all produced sizeable avalanches. On Flute Peak, a boarder got too close to the edge and fell onto the slope when the cornice broke. The resulting slab likely failed initially in the facets. Of note is the fact that this particular start zone ran on the facets once already in late November, and has been performing regularly throughout the winter.
On Feb. 6, a boarder in the Brandywine drainage triggered a size 2 avalanche in a cut block at 1,530 metres. The steep SW aspect appeared to fail on an old rain or temperature crust.
What has caused this renewal of avalanche activity? Has the new snow tipped the balance? Have the cold temperatures made the slab more brittle and reactive? Or can it be blamed on the increasing punch that the sun is starting to exert? Whatever the reasons, it is happening. As always, the susceptible slopes are the steep rocky ones with a shallow snowpack. Beware though that some of the larger cornice-triggered events are running well down into the flats, depositing rubble on the "moderately safe" routes of travel.
Put your "caution" hat back on again and stick to the lower angle, unexposed terrain. The forecast for continuing cool temperatures and bits of snowfall will likely only increase the rate of avalanche activity. Remember that good stability and low to moderate hazard ratings still allow for isolated killer events to occur.
The avalanche danger as of Feb. 7 is rated as MODERATE to CONSIDERABLE. Conditions may change rapidly. Call the avalanche bulletins or contact someone in the know for the most current information.