If lightning strikes a tornado...

What would happen if a lightning bolt hits a tornado? Nick, Lewisville, USA

A tornado touching down on May 3, 1999 in central Oklahoma. Photo courtesy of NOAA.

A tornado would scarcely notice lightning discharging through it. 

"The power surge is neither strong enough nor long enough to disrupt the tornado vortex," emails lead forecaster Roger Edwards of NOAA's Storm Prediction Center. 

The odds of a lightning bolt hitting a tornado are extremely small.  "I have watched a hundred tornadoes in person and videos of hundreds more; I haven't seen any examples yet."  Lightning does strike sometimes in front of or behind the tornado, which gives the illusion of actually hitting it.

Tornado winds, however, can change where lightning might strike, says Edwards.  As a negative electric charge builds in the cloud and a positive charge builds in the ground, an invisible charge channel "wiggles" down from the cloud, following the path of least resistance to ground.  But intense buffeting winds can deform the zigzagging channel, and cause other branches to be better paths.  Then the electrical charges choose the better path to neutralize the charge differential. 

Thus, a tornado's winds can affect lightning, but lightning can't disrupt a tornado's vortex.

Further Reading

The online  tornado FAQ, by Roger Edwards, NOAA

A SEVERE WEATHER PRIMER: Questions and Answers about TORNADOES, National Severe Storms Laboratory

Langmuir Lab Researchers' Volcanic Lightning Study In Science, New Mexico Institute of Mining and Technology

What causes lightning?  WonderQuest

(Answered April 14, 2008)

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