What is a Thunderstorm?

Mary McMahon
Mary McMahon

A thunderstorm is a storm that is accompanied with lightning and thunder, along with heavy rainfall or hail. Typically, these storms are relatively brief, resolving themselves within a few hours, but they can do a great deal of damage, especially in the case of supercells, massive thunderstorms that can pack a serious punch. Because of the potential danger, people are usually advised to stay indoors during such storms, and severe weather warnings may be issued to put emergency services on alert if a thunderstorm looks extremely dangerous.

Thunderstorms are more common in the tropics because of the warm, moist air found in equatorial regions.
Thunderstorms are more common in the tropics because of the warm, moist air found in equatorial regions.

In order for a thunderstorm to form, warm moist air must be present near the surface of the Earth. Because warm air is lighter than cool air, it rises up into the atmosphere. If the higher air is cooler, the moist air starts to condense, forming clouds. When conditions in the atmosphere are unstable, those clouds can turn into towering cumulonimbus, with a classic anvil shape. Eventually, the clouds release their moisture, generating a torrent of rain or hail in very cold conditions.

A series of storms can be very dangerous for mariners.
A series of storms can be very dangerous for mariners.

The unstable conditions also generate electrical charges that become lightning. As the lightning strikes, it generates thunder, which is caused by the superheated air generated by lightning as it streaks through the atmosphere. As this air expands, it forms a shock wave, which registers as thunder in human ears.

A squall line of thunderstorms may hammer an area repeatedly until all storms pass over.
A squall line of thunderstorms may hammer an area repeatedly until all storms pass over.

In a single cell thunderstorm, there is only one major source of warm, moist air, and the storm typically ends quickly because it essentially runs out of ammunition. Multi-cell storms have multiple sources, and many form up into a cell cluster or squall line, a series of storms that hammer an area repeatedly until all of the storms pass over. In the case of a supercell, the cloud actually breaks up through the troposphere, and the resulting storm has tremendous energy, which can in turn create hurricanes and tornadoes.

A thunderstorm is a storm that includes thunder and lightning.
A thunderstorm is a storm that includes thunder and lightning.

Thunderstorms are most common in the tropics, where warm, moist air abounds, and in some regions, small ones occur almost every day. These storms can potentially occur anywhere, however, even in the frigid arctic, and it is not always possible to predict them. Often, weather conditions suggest that a thunderstorm may be likely, and meteorologists can alert people to the danger, but in other cases, one seems to come out of nowhere, and to dissipate just as unexpectedly. As a general rule, anvil-shaped clouds, a heavy sky, and a feeling of tension are all good reasons to go indoors for a bit in case a serious storm develops.

The stratosphere is just above the troposphere, the layer of the Earth's atmosphere that comes into contact with the ground.
The stratosphere is just above the troposphere, the layer of the Earth's atmosphere that comes into contact with the ground.
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


I live in an area where we don't get many thunderstorms, but they still scare me out of my skin. What I do is I usually listen to the song Radioactive by Imagine Dragons. It has thundering noises, so it blocks out the sound of the thunder. I listen to it for the whole storm, and I don't hear a thing.


@SarahSon - Lightning is what scares me too. If I see it way off in the distance, it doesn't bother me so much, but when it is close, I like to stay far away from it.

When I was a kid I was always afraid of a thunderstorm and if they came in the middle of the night, I would not be able to sleep.

My mom always said the sound of the thunder was the angels in heaven bowling, and the lightning flashed whenever they got a strike.

To this day, I always think of that when I am in the middle of a thunderstorm. A few years ago we had a really bad one with a lot of hail damage. Within just a few minutes many crops, cars and homes were damaged from the hail that came with the storm.

I also had some neighbors who lost the roof of their barn because of high winds from a thunderstorm. This wasn't a tornado, but the winds were strong enough to cause a lot of damage.


@julies - I also live in an area where we get frequent thunderstorms. I thought this was something that was common all across the country, but this is not the case.

When a friend of mine from the West coast was going to college here, this was the first time she had been in a thunderstorm.

She said they never had them where she lived. They would get rain, but didn't have the thunder and lightning that you get with a thunderstorm.

I was intrigued by this and had never thought about it before. I don't mind the rain and the thunder, but a thunderstorm with lightning can scare me.

I have seen the lightning get pretty close before, and some times when I go outside after the storm has passed, I can see where the lightning struck a tree.

Personally, that is a little too close for comfort.


I have lived in the Midwest my whole life so I am used to summer thunderstorms. I enjoy some of them, as long as they don't turn into a severe thunderstorm.

I have a covered porch where I love to sit outside and watch the lightning flash across the sky, listen to the thunder and hear the rain fall.

I find the sights, sounds and even the smell of the rain during a thunderstorm to be exciting and yet soothing at the same time.

When the storm turns severe is when I don't enjoy them and make sure I stay inside the house. If there are strong winds that accompany the storm, they can do a lot of damage in a short amount of time.

I like the thunderstorms when you can hear the gentle rolls of the thunder and you get a nice, gentle rain with it.


I have had several dogs that can predict a thunderstorm is coming before I can. This is something that seems to bother them more the older they get.

They become agitated and nervous hours before the storm even arrives. One of my dogs would dig a hole under a shed and crawl under there during a thunderstorm.

My golden retriever, who never jumped up on the furniture, would try to jump up on my lap during a thunderstorm and sometimes she would be shaking.

I was always curious why the storms bothered them so much and how they knew they were coming. I think they must be able to sense a change in the atmospheric pressure somehow.

Many times the thunderstorm sounds of loud thunder will cause one of my dogs to howl, while the kids sleep right through it all.


I have heard that thunderstorms scare dogs because the charge causes static in their coat. I don't know if this is true or not, but for whatever reason, my normally fearless Doberman quivers during a thunderstorm, and she hides in the closet under my clothes.

I really think it may have more to do with the loud noises and the shaking of the house than with static. After all, she has extremely short hair, and I can't see it standing up at all.

I feel really bad for her, because there is nothing I can do to comfort her. I can't get her to come out of the closet!


Some of my friends only fear the thunderstorms producing tornados, but I fear them all. I have hated the loud boom and crack ever since I was little, and if hail comes with it, then I shake all over in fear.

There was a thunderstorm that produced golf ball size hail at my house a few years ago. It was coming down on the tin roof so hard that I couldn't hear the person standing right next to me talk. Paralyzed by fear, I just stood at the window and watched the hail bounce off the lawn.

Since it came in July, there was quite a big temperature difference between the ground and the hail. Once it had quit falling, we went outside, and steam was rising off of our newly white lawn. The grass was covered, as though it had snowed balls.

Though it had terrified me as it was happening, it was pretty cool to look at after the storm had passed. The whole thing was over in probably one minute.


@lighth0se33 – Thunderstorms make the hair on my body stand up sometimes. I wonder how our grandparents must have felt when they saw a storm coming. They had no radar or warnings to rely on, so the sound of a thunderstorm must have been a lot scarier to them.

My mother told me that every time they heard thunder, her parents would take the family into the storm cellar. This does seem a bit excessive by modern standards, but when you think about it, they had no way of knowing if they were in danger of getting hit by a tornado or hail. They just had to take every precaution.


It is weird how you can feel the electricity in the air when a thunderstorm is approaching. I always get a feeling of danger and uneasiness, and I want to get indoors as quickly as possible. My yard has received a lightning strike before, and I know the damage that it can do.

I have a shop in my backyard with a concrete floor. Lightning hit the antenna on top of the shop and traveled down to the foundation, where it split the concrete. That is some impressive power.

This has motivated me to stay out of the shop during thunderstorms. I feel much safer in my brick house.

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