A mesocyclone (or "meso" for short) is formed when a thunderstorm updraft meets veering winds. As the air rises in the thunderstorm, the winds will begin to twist the updraft until the whole ...

The rising air, or updraft, is essential because air cools as it moves up, and as a result, water vapor condenses to form precipitation. As the air cools at high altitudes, it starts to sink ...