Welcome to weather class. Today's subject is thunderstorms.
Thunderstorms are pretty common. In fact, it's estimated that there are nearly 100,000 thunderstorms a year in the United States.
How do thunderstorms form? It all starts with warm and wet air that rises quickly. When the air rises high enough, it forms cumulonimbus clouds, which can look like an anvil.
As the humid air rises the temperature drops, causing the water particles to freeze. When the frozen particles run into each other, they build up electrostatic energy. When enough electrostatic energy builds up, it's released in the form of lightning.
The lightning heats the air rapidly as it passes through it — so rapidly that it creates a loud noise. That loud noise is thunder. Since lightning is the cause of thunder, every thunderstorm also has lightning. But, the lightning doesn't always strike the ground.
In a thunderstorm, a lot of moisture has gone up into the clouds. When it gets heavy enough, it falls as rain. That usually means a lot of rain dropped in a short amount of time. In addition, the up-rush of air creates low pressure, which is quickly filled in by warm air, creating strong winds.
Thunderstorms pose threats we need to be aware of — fires from lightning, damage from high winds and flash flooding, to name a few. Pay close attention to weather reports. When you see or hear a thunderstorm watch, that means all the elements favorable to a storm are there. When a thunderstorm warning is issued, it's time to find a safe place. A storm has formed and there is a serious threat to life or property.