October 08, 2011
Photographer: Stephanie Rardin
Summary Authors: Greg Johnson; Jim Foster
These impressive hailstones crashed to the ground during an intense thunderstorm just south of Charlotte, North Carolina on April 9, 2011 (a little after 6:00 p.m. local time). The stone on the right features distinct concentric rings. This hailstone was approximately 1 3/4" (5 cm) in diameter at the time the picture was taken -- some slight melting had occurred since it was collected. The concentric ring or onion-like appearance of large hailstones results when raindrops are subjected to repeated updrafts and downdrafts. Each time the raindrop/hailstone falls in a downdraft a new layer of water is added, which freezes if the stone is then launched upward in a strong updraft. This cycle continues until the hailstone is finally jettisoned from the storm. The number of rings gives an indication of the number of times the hailstone was lifted upward. Hailstones as large as 3 in. (7.5 cm) in diameter were associated with this storm.