During which stage of a thunderstorm does rain begin to fall at the Earth's surface?

Rain begins to fall at the Earth's surface during the mature stage of a thunderstorm. This stage is characterized by the development of the storm's full structure, including an updraft that becomes strong enough to support large amounts of moisture. As the growth continues, the rising air cools and condenses, leading to the formation of precipitation.

In the mature stage, the updraft is balanced by a downdraft, allowing heavy rain, hail, and even strong winds to occur. This dual action of updrafts and downdrafts is critical because it sustains the storm and allows for significant rainfall that reaches the surface. The onset of the rain and the accompanying downdrafts signify that the storm has reached its most intense phase.

In contrast, during the cumulus stage, the storm is still developing, and no precipitation reaches the ground. The dissipating stage follows the mature stage when the storm begins to weaken and rainfall decreases. The steady choice does not represent a recognized thunderstorm stage. Thus, the mature stage is specifically identified by the onset of rain at the Earth's surface.