> SAN FRANCISCO, CALIFORNIA--The jury may still be out on whether lightning can strike the same place twice, but a new study gives the public another riddle to ponder: Can distant lightning bolts talk to each other? Evidence gathered from space shuttle recordings indicates that, rather than being randomly distributed, lightning flashes appear to be coordinated, even when they're far apart.
> Coordinated lightning behavior has been observed before, but only over short distances. Over the past 30 years, however, astronauts who watched thunderstorms from space reported believing that lightning strikes influence each other even when hundreds of kilometers apart, a phenomenon astronaut Edward Gibson called "sympathetic lightning bolts."
> Sympathetic lightning is the tendency of lightning to be loosely coordinated across long distances. Discharges can appear in clusters when viewed from space.[22][23][24]
> From observation of lightning activity in severe storms with VHF radar the echoes from lightning discharges following one another within a time interval typical for a multistroke cloud-to-ground flash and spaced in range by several km are designated "associated discharges". The hypothesis of association between lightning flashes is tested against an alternative hypothesis of independence between them by using methods of statistical analysis for series of events. The hypothesis of independence is rejected at a level of significance of 5%. The probability for lightning flashes in multicell storms to be associated increases when time intervals between flashes are very short (<100 ms for the investigated storm).
