Which type of cloud is associated with thunderstorms?

Cumulonimbus clouds are the type of cloud associated with thunderstorms. These clouds are large, towering, and often have a characteristic anvil-shaped top, which can reach great heights in the atmosphere. They typically form in unstable atmospheric conditions where warm, moist air rises, cools, and condenses, leading to the development of strong updrafts that can produce intense weather phenomena.

Cumulonimbus clouds are capable of producing heavy rain, lightning, hail, and even tornadoes, making them central to thunderstorm formation. Their vertical development and structure allow for significant convection, which is essential for thunderstorm activity. Other cloud types listed, such as stratus, cirrus, and nimboform clouds, do not have the same characteristics that facilitate the development of thunderstorms. Stratus clouds are low, grey clouds that typically bring light rain or drizzle; cirrus clouds are high, wispy clouds composed of ice crystals and generally indicate fair weather; while nimboform clouds, which are not commonly classified, could refer to rain-producing clouds that are usually in the stratus family. Thus, cumulonimbus clouds are uniquely suited to trigger the complex dynamics of thunderstorms.