Cumulonimbus clouds are characterized as tall, dense clouds which are generally accompanied with heavy thunderstorms. The clouds usually form in single mass or in clusters. Cumulonimbus clouds are a part of cumulus clouds which can take the shape of supercell accompanied with severe cloudburst. A perfect cumulonimbus cloud consists of loads of moisture which lifts the warm and moist air in upward direction that too in rapid speed.

Cumulonimbus clouds are a mass of warm unstable air with its formation along the front lines lying in close proximity to the oceans. The warm air usually ascends above the cool air whereby the hot air reduces and forms into water vapor thereby taking the shape of water droplets.

Due to condensation the surrounding air is heated which releases heat, thereby raising the air mass level. It is the gravity which brings along the water droplets which comes down as heavy downpour or light showers.

Cumulonimbus cloud are usually accompanied with heavy thunder and lightning. These clouds have ruthless convection currents and bring along unpredictable winds that too within a vertical plane. Cumulonimbus cloud formation can be dangerous for aircraft flyers.

Cumulonimbus clouds designs its formation mostly during the afternoon time, as this the time when the earth surface gets heated up. Cumulonimbus clouds are usually seen in the shape of mushroom; lying at an altitude of 3,000 to 4,000 meters (10,000 to 12,000 feet) while its peak extending to somewhere around 23,000 meters (75,000 feet). Heavy rain, straight line winds and flash flooding are a part of the Cumulonimbus clouds.