Well the short answer is we do not know. We have no clear definition of what it is nor how its created. Ball lighting can move upwards as well as downwards and sideways, or can possess odd trajectories such as veering off at an angle or rocking from side to side like a leaf falling.
Ball lightning can also move with or against the wind. Other motions include a tendency to float or hover in the air. Its shape has been described as spherical, oval, tear-drop, or rod-like with one dimension being much larger than the others. Colors reported include red, orange, yellow, green, blue, lavender, etc, sometimes transparent, sometimes translucent. Some contain radial filaments or sparks while others are evenly lit, and some have flames protruding from the ball surface.
The balls can be spinning or non-spinning. Sometimes the ball lightning is described as being attracted to houses, cars, objects or persons , sometimes as avoiding people etc, and sometimes as moving randomly. Many reports are of balls following on or near electric power lines. Several people report ball lightning following their cars, one report described ball lightning following and engulfing a car, causing the electrical system to overload and fail. After several seconds or minutes the ball lightning can just quietly immediately vanish, dissipate gradually, leave, disperse, be absorbed into something, just pop, noisily explode, or explode with violence, damage, and lethality.
Some accounts have the balls passing freely through wood or glass or metal, without any damage to the ball or material, while other accounts report melted vaporised circular holes in the wood or glass or metal. Some reports are of balls avoiding house wiring, some are of balls attracted to house wiring. Some reports are of balls touching house wiring and vanishing, some reports are of explosions with damage and wreckage when the balls contact house electrical wiring or circuit-breaker boxes. Some reports are of vaporisation of water when the balls enter water, some are of the balls entering and exiting water with no vaporisation.
One famous old account of a ball vaporising water found that the amount of water vaporised in the time the ball was in the water required an extremely, unbelievably, high amount of energy. Some accounts say the balls are lethal, killing on contact, while other accounts say the opposite. What the ball lighting actually is no ones quiet sure. Some believe it to be plasma but that would mean it would disipate quickly. The most common accepted idea is that it is plasmoid or highly ionized plasma which wold make it more stable other than that we do not know.
