Thanks for the fireballs so far, but ok, I should have written "ball lightning", "ball of thunder", my mistake. Here's more:
"Ball lightning discharges were once thought to be extremely rare occurrences, but recent research shows that a few percent of the US population have been witnesses (Uman). Ball lightning is photographed very rarely, and details of witness accounts can vary widely. Many of the properties observed in ball lightning accounts conflict with each other, and it is very possible that several different phenomena are being incorrectly grouped together. The discharges can appear during thunderstorms, sometimes issuing from a lightning flash, but large numbers of encounters occur during good weather with no storms within hundreds of miles. Ball Lightning tends to float (or hover) in the air and take on a ball-like appearance. The shape can be spherical, ovoid, teardrop, or rod-like with one dimension being much larger than the others. The longest dimension observed is between fifteen and forty centimeters. Many are red to yellow in color, sometimes transparent, and some contain radial filaments or sparks."
Surprisingly - there seems to be no photo (yet) of the natural event.