Quick report
This avalanche was remotely triggered. While no riders or recreators were caught or injured, the outcome could have been very different without proper precautions in place. The reported persistent storm slab was remotely triggered after six riders and skiers had already made safe descents. I believe that sun exposure and warming of the persistent weak layer on the south aspect of Microdot—consistent with conditions noted in the report—were key contributing factors. The warming of natural features likely played a significant role in triggering the approximately 18-inch to 24 inch-deep slab that released on the south side of Microdot around 1:00 PM AKDT.
Forecaster Comments:
After speaking with the reporting party, we have confirmed that approximately 5 individuals skied the run prior to the avalanche occurrence; some of their tracks are visible in the attached pictures, while the avalanche ran across the others. The observing party reported triggering a collapse along the Microdot Shoulder skin track on their ascent route. They also dug a pit along the ascent route and observed poor structure and stubborn but propagating test results. While it is likely that warming of adjacent rocks and the slope played a role in this slope's instability, it is most likely that an individual on the ridge, or the slope itself, remotely triggered this slab from a thin spot.