As a charge accelerates from the cloud to the ground during a thunderstorm?

Steve4Physics

This is really no different to dropping a ball (PE decreases, KE increases). But instead of acceleration being due to a gravitational field, it is due to an electric field. 1) The charge's electrical potential energy decreases. 2) The charge's kinetic energy increases. (It's actually a bit more complicated because energy is also converted to heat and light, but that doesn't change the basic answers.)