A hydrodynamic model of ball lightning leakage through a narrow opening in a plane screen

Based on results of numerous observations of ball lightning motion in air flows through wide and narrow openings in a plane screen, basic equations are derived within the framework of specially selected models to describe the motion of a ball lightning in air flows during its leakage through a narrow opening in a screen. It is shown that the attraction of a ball lightning to the screen opening in the presence of air drafts in any direction and the subsequent leakage of the lightning through the opening constitute a single purely hydrodynamic phenomenon.