WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.

Is there such a thing as dry lighting?

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Dear Tom,
Is there such a thing as dry lighting?

Audrey Clark

Dear Audrey,
Dry lightning is a colloquial term for lightning that occurs from a thunderstorm that is not producing precipitation. It's not a meteorological term and its implications are factually incorrect for two reasons.

Lightning, the transient flash of light produced by an electric discharge in the atmosphere (usually in thunderstorms, but also in volcanic ash clouds and, very rarely, in sandstorms) is never wet in the first place.
 
Secondly, thunderstorms always produce precipitation, but rain falling from a storm sometimes falls through a layer of dry air and evaporates before it reaches the ground. This is known as a dry thunderstorm (also technically a misnomer). Such storms occur in the western U.S. in the summer and are the leading natural cause of forest fires.