10 Facts About Tornadoes is supplied for use by writers and journalists who are preparing items for a more general audience, such as for publication in newspapers, the more popular magazine articles, etc.
Tornadoes revolve both anticlockwise and clockwise, regardless of the hemisphere.
This is because they are too small to be affected by the Coriolis force - the way the Earth's rotation deflects winds around high and low pressure areas. However anticlockwise tornadoes are more prevalent in the northern hemisphere because some tornadoes develop from a larger circulation in a thunderstorm which can be affected by the Coriolis force. It was the largest outbreak in US history, leaving 330 dead and 5,000 injured. Many sources report 148 tornadoes, although Dr. Fujita, a leading Amerian tornado researcher, reclassified 4 as microbursts - strong and damaging winds which descend from a thunderstorm. However it is possible that more than one tornado was involved.