Dear Tom,
My family was in Grayslake when a thunderstorm approached and produced what we believe to be ball lightning. Do you have any insight on this phenomenon?
Jason Warren Round Lake Park

Dear Jason,

Ball lightning, a moving luminous sphere observed during thunderstorms, probably exists. Reports indicate ball lightning globes, usually reddish, are typically grapefruit-sized and persist only a few seconds. Some skeptical researchers attribute its appearance to “persistence” of vision after seeing a close lightning bolt. This may have some validity because ball lightning usually is seen during thunderstorms producing many ground strikes. University of Florida lightning expert Martin Uman says 5 to 10 percent of the population has seen ball lightning, approximating the percentage who have seen direct lightning impacts. Uman says, “The implication is that ball lightning is usually created at or near the lightning channel.”