Thunderstorms are common all over the world. In this video lesson, you will learn what they are, how they form and how they create thunder and lightning.
What Are Thunderstorms?
Did you know that Florida has more thunderstorms per year than any other state in the U.S.? Or that if you are male you are 4.
6 times more likely to get struck by lightning than if you are female? Or that sound travels one mile in five seconds, so if you hear a lightning strike you can figure out how far away it was by counting the seconds until you hear the thunder clap?Thunderstorms are amazing and interesting events! Thunderstorms can occur almost anywhere and are the beginnings of some other dangerous storms like hurricanes and tornadoes. But just what is a thunderstorm, and how does it form? A thunderstorm is a storm with lightning and thunder. They are caused by an updraft, which occurs when warm, moist air rises vertically into the atmosphere. The updraft creates a cumulus cloud, which will eventually be the thunderstorm cloud.Updrafts can occur anywhere warm, wet air rises quickly, which is why most people, no matter where they live, have experienced a thunderstorm at some point in their life. However, some places, like Florida, are more prone to thunderstorms because the conditions that create thunderstorms are more common.
The Formation of a Thunderstorm
A warm updraft is just the beginning of a thunderstorm, though.
Once the air rises into the atmosphere, it begins to cool. Cool air can’t hold as much water as warm air, so as the air cools, the water in the air gets kicked out as condensation and may eventually fall back to the ground as rain. In order for this to happen, though, the cumulus cloud has to grow very tall.Think about it this way: If you’re playing a game of Red Rover and try to break through the human wall on the other side by yourself, you may not be very successful because there’s only one of you. But if you get all of your friends to crash into that line of people with you, you’ll have greater success because you are a large group with a greater force.
The same is true for water in the thunderstorm cloud. By itself, that single water droplet is not heavy enough to fall back to the ground as rain. But if the cloud is tall enough, that one little droplet will pick up other droplets with it and eventually grow into a large enough water droplet to break through and fall back to Earth.Just like the updraft was warm air rising upward into the atmosphere, a downdraft is cool air sinking back to the ground.
Downdrafts are created by the falling water droplets because they don’t just drag other water down with them as they fall, they drag cooler air down with them as well. The combined warm updraft and cool downdraft create a storm cell. As the process of warm air rising and cool air sinking continues, the cloud grows vertically into the shape of an anvil, which is called an anvil head cloud. This is now a full-fledged thunderstorm cloud, ready to storm away!
Thunder and Lightning
As you are probably aware, thunderstorm clouds can produce a lot of thunder and lightning.
What you may not know is that these are both produced from the same event. Lightning is what you see, thunder is what you hear. They appear not to occur at the same time because light travels faster than sound, so the image of the lightning reaches your eyes before the sound it creates reaches your ears.Here’s how it works: As the water droplets in the cloud fall downward, they bump into each other, which gives the cloud an electrical charge. The charge, however, is not uniform within the cloud; there is a negative charge in the warm areas and a positive charge in the cool areas. Eventually electricity builds up and electrical energy is released, flowing to the points of opposite charge because opposites attract! Much of this occurs within the cloud, but sometimes it leaves the cloud and heads toward the ground because the ground holds an opposite charge to the lower part of the cloud.
When this happens, we get lightning.If you’ve ever touched a light bulb that has been on for a while, you know that light produces a lot of energy as heat. When the electrical energy leaves the cloud as lightning, it also releases energy as heat, which warms the air around it.
When things heat up, they expand, and as the air expands, it releases a giant sonic boom – the thunder you hear. So you can see that while you may have lightning without thunder, you certainly won’t get thunder without a lightning strike.
Most of us are familiar with thunderstorms, which are storms that produce thunder and lightning. These can pop up out of nowhere or warn us that they’re coming with a dark, cloud-filled sky. Thunderstorms are common but are also the basis of many more dangerous storms, such as tornadoes and hurricanes.
Thunderstorms begin with a thunderstorm cloud, which develops from an updraft of warm, moist air rising vertically into the atmosphere. As the air rises it cools, and as it cools it pushes out the water it holds, creating a cumulus cloud full of condensation. If the water droplets in the cloud have far enough to fall, they drag along other water droplets as well as cool air.
If the water droplets collect enough backup, they fall back to the ground as rain. The cool air falling back to the ground with it is called a downdraft. When an updraft and a downdraft work together, they create a storm cell, which is the fully developed thunderstorm cloud.Thunderstorms create a lot of thunder and lightning, which happens because the water droplets bump into each other and create electrical differences in the cloud. If this electricity builds up enough it releases electrical energy, usually within the cloud itself.
Sometimes, though, it may leave the cloud and head toward the ground. When this happens, the lightning cuts through the air like a knife, heating it and causing it to expand.The thunder you hear is the sonic boom from the air cracking. While thunder and lightning do come from the same event, the reason you see lightning before hearing thunder is because light travels faster than sound. Knowing this will also help you calculate the distance of the lightning strike, but you may want to figure this out indoors so you don’t get caught in the rain!
Once you have finished this lesson, you should be able to:
- Summarize what a thunderstorm is and how it forms
- Define updraft, downdraft, storm cell and anvil head cloud, and know how these terms relate to thunderstorms
- Explain how thunder and lightning form, and understand why we see lightning before hearing thunder