ORLANDO, Fla. – You’re sitting at home during a thunderstorm when all of a sudden you hear a loud bang and your windows rattle so hard it seems as if the house will cave in.
What’s going on?
After a lightning strike is produced, in a split second, the lightning heats the surrounding air to astonishing temperatures, up to 54,000 degrees Fahrenheit! For perspective, that’s five times hotter than the surface of the sun.
The heated air then expands explosively which creates a shockwave as the surrounding air rapidly compresses. This makes the loud crack we hear.
As the shockwave rushes outward it can run into structures like your house, causing it to rumble or shake.
Essentially your house is shaking or rattling from those rapidly heated air molecules hitting it!
Cloud to ground lightning is the typical producer of house-rattling thunder. This is also the most dangerous type of lightning as it impacts the ground where we are.
How to estimate how far lightning is away from you
You just saw a flash of lightning, but you want to know how far away the strike is.
After you see the flash, count the number of seconds it takes for you to hear the thunder.
The general rule is every five seconds that passes between the lightning strike and rumble of thunder, the strike is 1 mile away.
For example, if you saw a flash of lightning and were able to count to 15 before you heard the thunder, simply divide by 5 and know that the lightning flash you just saw was a strike about 3 miles away.
If the clap of thunder immediately follows the lightning you are way too close for comfort!
You will always see the lightning flash before you hear the thunder because light travels faster than sound.