Wet or damp snowballs rolling down a slope. A precursor to wet avalanches.
Rollerballs and pinwheels are common precursors to wet avalanche activity. They cascade off of steep slopes when the snow surface starts to moisten or becomes wet. This sign of instability is easy to identify: you’ll see clusters of snowballs or cinnamon roll shaped snowballs rolling down the slope. As stability deteriorates, they start to entrain more snow and may develop into loose wet avalanches.