What is the first stage of a thunderstorm called?

The first stage of a thunderstorm is known as the cumulus stage. During this initial phase, the process begins with the rising of warm, moist air, which leads to the formation of cumulus clouds. As this warm air continues to rise, it cools and condenses, causing the water vapor to turn into liquid droplets, which build the cumulus clouds. This stage is characterized by updrafts, and there is generally no precipitation at this point.

The cumulus stage sets the foundation for the development of the thunderstorm, as it leads to further growth and the eventual formation of a mature thunderstorm, where heavy precipitation and downdrafts become prevalent. Understanding this stage is crucial for identifying how thunderstorms develop and recognizing the potential for severe weather later in the process.