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Q&A: 'Lightning Alley' location makes Tampa Bay area dangerous during storms

The dangers of 'Lightning Alley'

I heard an interview recently with Tampa police Chief Jane Castor about the Republican National Convention. She was talking about the weather and said Tampa is the lightning capital of the world. Is that correct?

The chief was close, and at one time she would have been correct as far as the rest of the world knew. But about 10 years ago NASA scientists studying satellite sensors determined that Rwanda, a country in Central Africa, has 82.7 lightning flashes per square kilometer per year. By contrast, Florida receives 35.4. There are more than 22 million lightning flashes a year in the United States, and about 1.4 billion worldwide.

But Florida is the lightning capital of the United States, and Central Florida — from Tampa to Titusville — is the lightning capital within the capital. It's called "Lightning Alley." And that certainly makes the Tampa Bay area a dangerous place to be during a storm, even though the odds of being struck are in the ballpark of 1 in 750,000.

The National Weather Service says an average of 60 people are killed by lightning strikes every year in the United States, and 300 are injured.

Here are some tips from the NASA website on staying safe during a storm:

• "When you see lightning flash, count the number of seconds until you hear its thunder. If the thunder rolls in 30 seconds or less, the storm is already close enough to be dangerous; if you're not already in a safe place, it's past time to find one. After the storm, remain indoors for at least 30 minutes after hearing the last clap of thunder."

• "The safest shelter is a large, fully enclosed building with wiring and plumbing, such as a typical house, school, store or public building. If none of these are available, the next best option is any vehicle that has a solid metal roof and solid metal sides, like the average car, bus or truck."

• "Once inside, avoid any conducting path to the outside. Don't use a corded phone; only use a cordless phone if you are away from the base station (where the phone is recharged). Stay away from televisions, computers and appliances. Plumbing is equally dangerous."

In storms, flashes precede bangs

What causes thunder and what is the relationship between thunder and lightning?

Thunder is the sound produced by lightning. During a lightning strike, electrical energy is discharged along a path surrounding the lightning. A sudden and violent expansion and explosion of super-heated air in and along the length of this channel creates the sound waves that we hear as thunder.

Because light waves travel through air faster than sound waves do, we see lightning before we hear the accompanying thunder. The Lightning Safety Group, an interdisciplinary group of the nation's lightning experts, has calculated that the ratio from flash-to-bang is approximately 5 seconds for each mile. Just remember, "When lightning roars, go indoors."