What about Thunderstorms?
Thunderstorms are one of the most common and most noticeable weather products of our atmosphere. They form worldwide, spit out deadly lightning, band together to form hurricanes, and can spin up the world's fastest winds inside tornadoes. Thunderstorms can throw one of nature's most spectacular shows, but at the same time prove to be deadly. Dangers associated with thunderstorms can include lightning, hail, heavy rain, flooding, strong winds associated with downbursts, microbursts and tornadoes.
What are Thunderstorms?
The key ingredient that defines a thunderstorm is lightning. Since lightning creates thunder, a storm with lightning is called a thunderstorm. Thunderstorms come in all shapes and sizes with some cells only a few miles in diameter and some clusters of storms, known as mesoscale convective complexes that span hundreds of miles across.
Lightning always precedes thunder because lightning causes thunder. A lightning bolt can heat the air it passes through to temperatures as high as 54,000 degrees Fahrenheit. It is the quick and intense heating of the air that generates shockwaves, which propagate rapidly away from the lightning bolt. These shockwaves become sound waves as they travel through the air. This is how thunder is produced. Sometimes thunder rumbles on long enough that you see another lightning flash, which could lead to a false conclusion that thunder comes before lightning. When this occurs, you are hearing the thunder from a previous lightning flash.
When is a Thunderstorm Considered 'Severe'?
When certain atmospheric conditions coexist, a general thunderstorm can become severe. According to the National Weather Service, a thunderstorm is classified severe when winds reach or exceed 57.5 mph or produces hail three-quarters of an inch (size of a dime) in diameter or larger.