Some approaches:

http://www.technologyreview.com/view/418887/magnetically-induced-hallucinations-explain-ball/

http://www.abc.net.au/science/articles/2008/03/20/2194630.htm

http://www.newscientist.com/article/dn9293-physicists-create-great-balls-of-fire.html

http://physicsworld.com/cws/article/news/2006/feb/09/great-balls-of-lightning

http://physicsworld.com/cws/article/news/2008/feb/21/scientists-probe-fireballs-with-x-rays

http://www.newscientist.com/article/dn19789-space-debris-may-cause-mysterious-ball-lightning.html

Regards,

Joachim