Thunder

A streak of lightning is seen above the skyline of Nanning during a thunderstorm...A streak of lightning is seen above the skyline of Nanning during a thunderstorm in Guangxi Zhuang Autonomous region June 5, 2014. Picture taken June 5, 2014. REUTERS/Stringer (CHINA - Tags: ENVIRONMENT CITYSCAPE) CHINA OUT. NO COMMERCIAL OR EDITORIAL SALES IN CHINA

China Stinger Network/Reuters

A streak of lightning is seen above the skyline of Nanning during a thunderstorm in Guangxi Zhuang, China

Lightning strikes during an evening thunderstorm on May 29, 2014 in the Haitian capital Port-au-Prince.

Hector Retmal/AFP

Lightning strikes in Port-au-Prince, the capital of Haiti

TOPSHOTS A long exposure shows lightning...TOPSHOTS A long exposure shows lightning in the sky with reflection in the water on the floor of a building under construction during an evening thunderstorm on May 19, 2014 in the Haitian capital Port-au-Prince.   AFP PHOTO/Hector RETAMALHECTOR RETAMAL/AFP/Getty Images

Hector Retamal/AFP

A thunderstorm in Port-au-Prince, the capital of Haiti, on Tuesday 

Lightning from a thunderstorm strikes amid the wreckage of twisted cars and structures at Plaza Elementary School, where seven children were killed earlier in the week when a tornado hit Moore, Okla., Thursday, May 23, 2013. The huge tornado roared through the Oklahoma City suburb Monday, flattening entire neighborhoods and destroying the elementary school with a direct blow as children and teachers huddled against winds up to 200 mph. (AP Photo/Brennan Linsley)

Brennan Linsley/AP

Lightning from a thunderstorm strikes on Thursday amid the wreckage of twisted cars and structures at Plaza Elementary School, where seven children were killed when a tornado hit Moore, Oklahoma. The tornado tore through the town on Monday, flattening neighbourhoods and destroying the elementary school with a direct blow as children and teachers huddled against winds of up to 200 mph.