Speed of sound is about 5 seconds to the mile.
Number of seconds from flash to bang / 5 = number of miles to epicentre*.
* or whatever lightning has
(
Newington, Mon 4 Jul 2005, 15:05,
archived)
I think the meteorologists' term is
a 'bastard'. As in "Look! There's the bastard!"
(
Flapjack I spay a little mare for you, Mon 4 Jul 2005, 15:12,
archived)