[thedoc (OP)]

Lisa Sek  asked the Naked Scientists:
   
Hi there,

I live in Terrace Bay, Ontario, and I saw the strangest thing happen with Horizontal Lightning. So strange that it compelled me to write this e-mail.

I saw two horizontal lighting bolds hit one another. When they met there was no sound and the ends of the opposing sides balled up into growing rounds of yellowing light that suspended in the sky for about 5 seconds. The cord of lighting between the two balls of light disappeared and the two lightning balls continued to grow larger as if there were two twin rounds of fire in the sky. They continued to grow slightly larger, into more intese light, and then there was an unreal 'boom' that shook neighbourhood homes, and temporaily made all the power go out for a second.

What was this phenomenon called? Is it common? How is it caused? Are there any recorded photographs of this?

Thanks,
Lisa
   
What do you think?

[Boogie]

Perhaps some form of ball lightning?
http://weatherquesting.com/ball-lightning.htm