The atmospheric plasmoid hypothesis builds on laboratory observations that electrical discharges over water surfaces can generate self-contained balls of luminous plasma. In nature, this mechanism could operate when conventional lightning strikes a body of water — a lake, river, ocean surface, or even waterlogged soil. The enormous energy of the lightning bolt would vaporize water and dissolved minerals, creating a superheated cloud of ionized gas that, under the right conditions, could organize into a spherical plasmoid sustained by internal electromagnetic fields. This theory is attractive because it provides a natural mechanism for ball lightning that doesn't require exotic physics — it uses the known energy source (lightning) and a common environmental feature (water) to explain the phenomenon.
It also explains the frequently observed association between ball lightning and water: sightings are disproportionately reported near rivers, lakes, coastlines, and during rain. However, the theory does not easily account for ball lightning observed far from water or in dry conditions.