|
MYTH: Lightning never strikes the same place twice.
 |
 |
By DAN ROBINSON
Storm Highway Editor/Cameraman |
TRUTH: The old saying that 'lightning never strikes the same place twice' is another myth that any veteran storm observer or researcher has seen nature defy. Lightning can strike any location more than once. In fact, given enough time, it is actually inevitable. It may take as little as less than ten minutes within a single thunderstorm, or longer than a million years - but lightning will eventually strike the same spot again and again. A strike to any location does nothing to change the electrical activity in the storm above, which will produce another strike as soon as it 'recharges'. The previously hit location is then just as fair game for the next discharge as any other spot.
| Mythbusters Adam Savage and Jamie Hyneman tackled this myth using my footage of the Sears Tower getting struck by lightning twice during a July 2006 storm in Chicago. You can view the video clip at the Discovery Channel web site. |
 |
Lightning strikes twice? How about nine times in a couple hours in St. Albans, WV on June 3, 2008:
VIDEO CLIP: Lightning hits tower 9 times
Or how about eleven times - in 20 minutes! The images below show ten out of a total of eleven strikes in a 20 minute time frame to the WKYT / WTVQ towers in Lexington, Kentucky during a storm on February 5, 2008:
(video clip)
   
   
 
The Sears Tower in Chicago is hit by lightning an estimated 40 to 90 times per year. The first two strikes shown below happened within two minutes of each other.
Tall television towers and large skyscrapers blow the 'lightning never strikes twice' myth out of the water. A television tower's antenna often experiences a direct strike as frequently as every thirty seconds during more intense thunderstorms, with a total of three to over a dozen strikes per every half-hour interval that a storm is overhead. A observer wishing to witness a predictable close lightning strike has to go no further than his local television tower during a storm. Towers or skyscrapers that reach or exceed the 1,000 foot mark are virtually guaranteed to take at least one direct hit during every thunderstorm that passes overhead.
Between April of 2005 and July of 2006, I undertook a project to document lightning strikes to the 1,500 foot WVAH television tower near St. Albans, West Virginia. During the course of the project, I recorded fifteen strikes to the structure on camera. I didn't make it to every storm that occured at the tower, and I witnessed many more strikes that my cameras could not catch due to heavy rain and winds.
  
At the WVAH television tower in St. Albans, West Virginia, multiple strikes are common. These images show lightning striking the 'same place' not only twice, but three times in five minutes during a July 2006 storm.
So what about your house or your favorite tree? Lightning data shows that for climates with moderate thunderstorm activity such as Pennsylvania, New York and West Virginia, lightning will strike a typical quarter-acre area of land (of course, excluding those with tall buildings or towers) once every 100 years. So, statistically speaking, for these areas you could expect lightning to strike any location again in each century. Of course, for locales with higher storm frequency such as central Florida, the repeat strikes would occur in even smaller time periods.
But lightning doesn't have to follow the statistics. Any object could be struck again at any time, even during the same storm, so don't ever assume a recent strike makes a spot safe from another strike.
Frequency of strikes to skyscrapers and towers
|
 RIGHT: The John Hancock Center in Chicago, its antennas rising over 1,400 feet high, is also struck by lightning multiple times during thunderstorms.
If you were to perform an internet search to find the number of times lightning strikes a specific structure in an average year (the Sears Tower or Empire State Building, for example), you'll find figures ranging from the hundreds to the thousands. Which numbers are right? Based on our observations and collected images of actual tower/skyscraper strikes, a structure in the midwestern and northeastern USA with a height over 1,500 feet AGL (above ground level) receives an average of between 2 and 6 strikes during each thunderstorm that passes directly over the structure (a few thunderstorms produce no strikes to the structures, while in rare instances some can produce a dozen or more).
Given the fact that places like downtown Chicago, downtown New York City, and the WVAH tower site at West Virginia receive roughly 10-15 thunderstorm events that pass directly over the structures annually, we can conclude that these structures receive an estimated 40 to 90 strikes per year, with anomalous years likely producing no more than 125.
Tall structures in locations such as central Florida (regions that see many more thunderstorm days per year than the midwest or northeast) are more likely to have storms pass directly overhead. Therefore it is plausible that any tall broadcast tower (over 1,200 feet AGL) in the Florida 'lightning alley' would see well over 100 strikes per year.
See Also:
|
