If you've ever laid back on the ground during a warm summer's day, you already know that clouds come in all sorts of interesting shapes and sizes. For meteorologists, though, clouds are much more than funny shapes in the sky. To them, clouds can tell a lot about the weather. Under certain conditions, clouds can turn into thunderclouds, bringing violent showers, hailstorms and tornadoes to any given area.
Clouds are huge collections of water or ice particles in the air.
As the sun's rays warm our planet, they cause water from lakes, rivers, and oceans to evaporate, or change form from a liquid to a gas. The water vapor then travels upward until it reaches a part of the sky where it gets cold enough to condense back into droplets of water. These droplets aren't heavy enough to fall back to Earth, so they remain suspended in midair until the right conditions cause them to fall back to the earth as rain or snow. Although clouds seem weightless up in the sky, many of the ones that we can see are actually a lot heavier than you might think. When the earth is heated by the sun, it warms up the air closest to the ground.