Dear Mr. Skilling,
How many different kinds of lightning are there?
Lizzie Sweet, Naperville, Ill.
Dear Lizzie,
Meteorologists classify lightning in many ways, but the most important distinction is between those bolts that occur entirely within-air and those that strike the ground (or a ground-based object such as a tree or building).
Lightning bolts occur in staggering numbers–more than 100 million annually just in the U.S.–and about one in four of those 100 million bolts are ground strikes. That means the United States takes 20 to 25 million lightning hits in an average year. Among the 50 states, Florida leads the pack with one million ground strikes annually.
When lightning strikes the ground, the primary current-carrying bolt transfers electricity downward in 90 percent of the cases, and upward in the remainder.
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Tom Skilling is chief meteorologist at WGN-TV. His forecasts can be seen Monday through Friday on WGN-TV News at noon and 9 p.m.
Write to: ASK TOM WHY, 2501 Bradley Pl., Chicago, IL 60618 or asktomwhy@wgntv.com (Mail volume precludes personal response.)
WGN-TV meteorologists Steve Kahn, Richard Koeneman and Paul Dailey plus weather producer Bill Snyder contribute to this page.
