10:58pm February 20th, 2020 [Facebook]
This size 4 avalanche on Whistlers Peak was remotely triggered by a skier. The skier was 100 m away at the time, in a shallow, wind effected area.
It is important to remember that there are very different snow zones in the Jasper National Park forecast region. These snow profiles show the differences. The first, from the Icefields Parkway, shows a deeper (240cm), uniform snowpack with some surface variations (likely new and old windslab). The second profile, from the Whistlers Creek area, shows a significantly different snowpack. Weak basal layers (large facets and depth hoar) are far more pronounced. These differences are striking and were the notable factor in the remote, skier triggered size 4 avalanche on Whistlers Peak.
The lifting of the seasonal caribou habitat closures in the Tonquin (opened Feb 16) and Maligne/Brazeau (opens Feb 29) opens up a significant amount of new terrain for recreation. The snowpack in these areas will again be different but, the deep instability will remain with us until the snow melts away.
The deep persistent slab problem is proving to be a very complicated puzzle that requires careful observation and conservative decision making. This is the quintessential Rocky Mountain snowpack where many of the obvious signs of snowpack instability and avalanche hazard are often subtle and hard to discern. Use good travel habits, minimize your exposure to large features (especially when there are other users above), carry avalanche safety gear and always have a means of emergency communication (cell phones are not reliable in the Jasper backcountry).