ROCKFORD, Ill. (WTVO) — We’ve had quite a few thunderstorms across the Midwest so far this Summer; many of those storms produced a lot of lightning. But have you ever been outside and noticed lightning off in the distance, but couldn’t hear any thunder? Meteorologist Savanna Brito explains the science behind the common misconception of ‘heat lightning’.
Heat lightning is often a common phrase we hear during warmer months, especially during the hot and muggy summer nights. It’s a common thought that the heat and humidity are responsible for the lightning you see in the distance. But that lightning is actually a thunderstorm so far away, that you can still see the light from the lightning being reflected off the higher level clouds of the storm, but you can’t actually hear the thunder. That’s because the speed of light travels faster than the speed of sound.
Our eyes see the light before our ears hear the thunder because sound dissipates throughout the atmosphere. Sound can only travel for about 10 miles from the actual flash itself.
So how does lightning happen? Well a thunderstorm is full of electrical charges, both negative and positive, and where those charges reside within a storm cloud. Positive charges are at the top, while negative charges are in the middle and bottom.
Electrons begin moving down towards the bottom of the storm cloud and ground in what’s known as a ‘stepped leader’. As that leader nears the ground, it draws a positive charge upward from objects on the ground, known as an upward streamer.
As the leader and steamer merge, a powerful electrical current flows. This process may repeat several times along the same path, causing a flicker. And the crazy part? It all happens in less than a second. In fact, it is so fast, we do not actually see the lightning, it is the return stroke that is visible to us.
Often objects on the earth’s surface or simply the curvature of the earth itself prevents a person from seeing the actual lightning flash.
There are many different types of lightning, but the most common forms are intracloud lightning and cloud to ground.
If you hear thunder, lightning is close enough to strike. That’s because lightning can travel up to 10 miles outside of the main thunderstorm cloud. About 10% of lightning strikes occur without visible clouds.
The safest place to be during a thunderstorm is indoors and away from windows. If caught outside in a storm, move indoors right away. Standing outside by a tree, in an open field or near/in a body of water are some of the worst places to be when there is lightning and thunder. If no shelter is nearby, your vehicle is the next best place.
A lot of people think a car will keep you safe due to the rubber tires during a lightning storm, but it’s actually the metal shell on a car that keeps you safe.
So the next time you see lightning in the distance but can’t hear any thunder, you now know it’s a thunderstorm very far away, one that could be moving towards you.