In and around Whitefish Mountain Resort today, we found obvious signs of avalanche danger. And evidence that might lead you to think there was no problem.
The triggered slides and collapsed slab have far more weight in my calculations than the test results.
On a ski cut near the bottom of a slope and above a road cut, a patroller triggered a slide that broke above him and "knocked him on [his] butt." The patroller was briefly carried in the debris but not buried or injured. The general area had been mitigated with explosives the day prior, and that morning the patrollers had thrown several shots on their way down from the ridge above, and done multiple ski cuts. This cut was on the steepest part of the slope. The slope was logged the previous summer, leaving it more susceptible to top loading from the southwesterly winds. The failure plane for the slide was a layer of heavily-rimed grains that included a few very large (30-50mm), well-preserved surface hoar grains that likely formed on 12/12 and was perhaps buried 12/14. The debris mostly piled up on the cat road below, with the deepest part of the debris estimated to be about 7 feet deep. Some debris ran off the far side of the cat track. A second patroller on the team also reported triggering a slide that broke above him; the debris made it difficult to control his skis but he escaped without being carried.
New and drifted snow triggered during mitigation. Did not step down to buried surface hoar.
Triggered during mitigation. Similar depth as slide which caught patroller, but not nearly as wide.
