What charge does the bottom of a thundercloud typically have?

In a thundercloud, the bottom part typically accumulates a negative charge. This phenomenon occurs due to the process of charge separation within the cloud. As water droplets and ice particles interact and collide in the turbulent atmosphere of the cloud, they transfer electrons from one particle to another. The lighter ice crystals tend to gain a positive charge and are carried upwards by updrafts to the top of the cloud, while the heavier, negatively charged water droplets tend to settle toward the bottom. This results in the bottom of the thundercloud becoming negatively charged. This charge imbalance is a critical contributor to the development of lightning, as it creates a potential difference between the cloud and the ground or between regions within the cloud.