13K views · 347 reactions | Tornadoes occur on nearly every continent on Earth. Tornadoes form during thunderstorms, when warm moist air collides with cool dry air but will only form when the atmospheric conditions are just right. One of the great mysteries of science is why one storm will produce tornadoes and another won't. Watch Mutant Weather on Sundays at 7pm on National Geographic UK. | National Geographic UK | Facebook

Video shows a tornado on the ground in Central City, Kentucky, late Friday night as sirens ring throughout the town. Storms unleashed devastating tornadoes late Friday and early Saturday across parts of the central and southern US including Kentucky, where the governor says he believes the death toll will exceed 50. More than 30 tornadoes have been reported in at least six states. A stretch of more than 200 miles from Arkansas through Kentucky might have been hit by one violent, long-track twist