A thunderstorm brings lightning and thunder. It usually brings heavy rain, too. Sometimes it brings hail. Hail is made of balls of ice. They fall from the storm cloud.

Where does the water in a storm come from? Rain and snow start as water. It rose into the air from oceans, lakes and rivers. Water in the air is called water vapor. It is a gas. You cannot see it.

Lightning is a giant spark of electricity in the sky. Thunder is the sound that lightning makes.

You see the flash of lightning before you hear thunder. Light travels much faster than sound. So the flash gets to you first.

When thunder roars, go indoors. A building is safe. So is a car with a roof.

A tornado is a spinning column of air. It reaches from a storm cloud down to the ground.

A hurricane is a huge spinning storm. It forms over warm ocean water.

Words to know

• hail: balls of ice
• tornado: spinning storm
• hurricane: ocean storm
• vapor: water gas