At what stage is a thunderstorm when precipitation starts to fall?

The mature stage of a thunderstorm is characterized by the presence of precipitation and the development of strong updrafts and downdrafts within the storm system. During this stage, the thunderstorm reaches its peak intensity, and cloud droplets coalesce into larger drops that begin to fall to the ground as rain or other forms of precipitation. The dynamics within the storm can also lead to the formation of thunder, lightning, and even severe weather phenomena such as hail or tornadoes.

In contrast, prior stages, such as the cumulus stage, are characterized by the initial development of the storm without any precipitation reaching the ground. The dissipating stage occurs after the mature stage when the storm begins to lose its intensity and precipitation decreases significantly. The initial stage is also not associated with precipitation, as it refers to the early development of the cumulus clouds before they mature into a thunderstorm. Thus, the mature stage is rightly identified as the phase when precipitation begins to fall, marking the thunderstorm's full development.