A number of years back I was on a BSA camping trip at Philmont New Mexico. We all were lined up for lunch, and out of the corner of my eye I caught a glimpse of ball lightning shortly before it exploded. The guys who actually got a good look at it said it lasted around ten seconds or so, and was maybe fifteen to twenty feet above out heads. It sounded like a small bomb going off, but we didn't feel any pressure wave. Needless to say it was one of the weirdest things I've witnessed shortly after / between stormy weather.