Emerald Robinson: Hi, I'm Emerald Robinson, and in this What Is video, we're going to answer the question. What is a storm?

A storm is defined as any disturbance in a planet's atmosphere that brings about a change in weather.

On Earth these changes may include higher gusting winds, rains, snow, fleet or hell. Specific types of storms include snow storms, wind storms, cyclones and thunder storms.

Although there are many different types of storms, most form when an area of warm wet air and colder dry air collide, in a zone called Front. The warm air is forced to rise above the cold air causing an area of a low atmospheric pressure which acts sort of like a vacuum.

Winds blow as more cold air rushes in to fill the vacuum. The upward movement of air also sometimes causes the clouds we associate with storms.

Although what people call a storm varies widely. Scientists who study weather called meteorologist said a storm's minimum wind speed at 55miles per hour.

Storms can last for as little as an hour or for well over a hundred hours depending on atmospheric conditions.

Although they are sometimes dangerous to human, storms serves important purposes in nature. Precipitation from storms plays a crucial part in the water cycle.

Winds create large waves on bodies of water and turn up lakes and rivers. These actions are beneficial form marine life, as they equalize the water temperature and help to push plankton and other organisms that live near the surface of the water down to the lower depths, where they can be consumed by predators.

Storms are not exclusive to earth, astronomers have noted violent wind storms on planets like Mars and Saturn, Jupiter's well known great red spot is actually a huge storm that's been raging for at least a 183 years.