A thunderstorm occurs from a cumulonimbus cloud. They produce deadly lightning and can be dangerous to people, animals, crops and property.
They also bring rain to many areas of the United States, providing much needed moisture to plants and animals, keeping reservoirs replenished and rivers, lakes and streams full.
In a thunderstorm, you will find lightning and thunder. The lightning present in all thunderstorms is an electrical discharge that balances the difference between positive and negative charges within a cloud, between two clouds, or between a cloud and the ground.
Thunder is an explosion of noise heard when atmospheric gases are suddenly heated by a discharge of lightning.
Thunderstorms are sometimes accompanied by heavy rain, gusty winds, hail and can, under the right atmospheric conditions, spawn tornadoes.