What Is a Tornado?

Ages 3-5 Simple Explanation

You know how when you stir water in the bathtub really fast, it makes a little spinning swirl? A tornado is like that, but instead of water, it is air — spinning really, really fast. It comes down from a dark storm cloud and touches the ground, and the wind inside is super strong.

Tornadoes look like a long tube or funnel hanging down from the sky. Sometimes they are skinny, and sometimes they are really wide. They can pick up things like sticks, signs, and even roofs of houses because the wind is blowing so fast. That is why tornadoes can be dangerous.

If a tornado is coming, your grown-ups will take you to the safest place in your house. That is usually a room in the middle of the house on the lowest floor — like a bathroom or a closet with no windows. You get low to the ground and cover your head. The tornado usually passes by pretty fast.

Tornadoes do not happen everywhere all the time. They mostly happen in certain parts of the country when big storms come through. Weather people on TV and on the radio can warn your family ahead of time so everyone can get to a safe place. Your grown-ups know exactly what to do, and your job is to stay close to them and follow their directions.

Ages 6-8 More Detail

A tornado is a fast-spinning column of air that connects a thunderstorm cloud to the ground. The air inside a tornado spins at incredible speeds — sometimes over 200 miles per hour. That spinning wind is strong enough to tear roofs off houses, uproot trees, and throw cars into the air. Tornadoes are one of nature's most powerful forces.

Tornadoes form during certain kinds of thunderstorms. When warm, moist air near the ground meets cold, dry air up above, the atmosphere can become unstable. If wind at different heights is blowing in different directions, it can start the air spinning. When that spinning air gets pulled upward into the storm and stretches down to the ground, it becomes a tornado.

Most tornadoes in the United States happen in a region called Tornado Alley, which stretches through Texas, Oklahoma, Kansas, Nebraska, and nearby states. Spring and early summer are peak tornado season because that is when warm and cold air masses clash the most. But tornadoes can happen in other places and at other times of year too.

Tornadoes are measured using the Enhanced Fujita scale, which goes from EF0 to EF5. An EF0 tornado has weaker winds and might break some tree branches. An EF5 tornado has winds over 200 miles per hour and can level entire neighborhoods. Most tornadoes are on the weaker end of the scale, but even a small tornado is dangerous.

When weather experts think a tornado might form, they issue a tornado watch, which means conditions are right for tornadoes. If they actually spot a tornado or see one on radar, they issue a tornado warning, which means one is happening right now and you need to take shelter immediately. Knowing the difference between a watch and a warning is important.

The safest place during a tornado is in the lowest level of a sturdy building, in a small interior room away from windows — like a bathroom, closet, or basement. If you are at school, your teacher will lead you to a hallway or safe room where you will crouch down and cover your head. Tornadoes usually pass quickly, but those safety steps matter a lot during the seconds they are overhead.

Ages 9-12 Full Explanation

A tornado is a violently rotating column of air that extends from the base of a thunderstorm cloud to the ground. What makes tornadoes so destructive is their wind speed — the strongest tornadoes can have winds exceeding 300 miles per hour, which is powerful enough to sweep away entire houses and turn everyday objects into dangerous debris flying through the air.

Tornadoes form under specific weather conditions. They usually develop from a type of thunderstorm called a supercell, which is a long-lasting storm with a deep, rotating updraft. Supercells form when warm, humid air near the ground collides with cooler, drier air at higher altitudes, creating instability. If the wind speed or direction changes with altitude — a condition called wind shear — it can cause the air to start rotating horizontally. The storm's updraft then tilts that rotation vertical, and when it tightens and descends to the ground, a tornado is born.

The central United States sees the most tornadoes on Earth, largely because of its geography. Warm, moist air flowing north from the Gulf of Mexico regularly collides with cold, dry air sweeping down from Canada, and dry air coming east from the Rocky Mountains. This three-way collision creates ideal conditions for severe thunderstorms and tornadoes. The region is called Tornado Alley, though tornadoes can and do happen in every state.

Tornadoes are rated on the Enhanced Fujita (EF) scale from EF0 to EF5, based on the damage they cause. An EF0 might peel off some roof shingles, while an EF5 can destroy well-built homes down to the foundation. Only about 1% of tornadoes reach EF4 or EF5 status, but those account for the majority of tornado-related deaths. The most important factor in surviving any tornado is having shelter and knowing to use it.

Modern weather technology has made tornado forecasting significantly better than it was even a few decades ago. Doppler radar can detect the rotation inside a thunderstorm that signals a tornado may form. Storm spotters — trained volunteers on the ground — confirm what radar shows. The average lead time for a tornado warning is now about 13 minutes, which does not sound like much but is often enough to get to a safe room. In the past, many tornadoes struck with no warning at all.

If a tornado warning is issued for your area, go immediately to the lowest floor of a sturdy building, ideally a basement. If there is no basement, get to a small interior room like a bathroom or closet on the ground floor, away from windows. Cover your head and body with blankets, pillows, or a mattress to protect against flying debris. If you are in a car or outside with no building nearby, lie flat in a low ditch and cover your head — but getting to a real shelter is always the better option. After the tornado passes, watch out for downed power lines, broken glass, and weakened structures.