Which cloud genus is typically associated with thunderstorms and lightning?

Cumulonimbus is the cloud genus typically associated with thunderstorms and lightning.

Cumulonimbus clouds are deep, vertically developed clouds produced by strong convection. Warm, moist air rises rapidly, cools, and condenses into a towering cloud that can extend from low levels to the upper troposphere. The cloud’s top may spread into a flat anvil when it reaches a stable layer near the tropopause.

These clouds can produce heavy rain, hail, lightning, thunder, strong gusts, and tornadoes. Their presence indicates powerful upward and downward air currents, but not every cumulonimbus cloud produces every severe-weather hazard.

Cumulonimbus is commonly confused with nimbostratus. Nimbostratus produces widespread, usually steady precipitation, while cumulonimbus is more vertically organized and commonly produces showers or thunderstorms. The word combines Latin roots associated with a heap and a rain cloud.