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50 Amazing Tornado Facts

Tornadoes around the world


Twister central: The United States is the site of about 85 percent of the world's tornadoes. (Image credit: NOAA.)

While the United States is essentially the tornado capital of the world, tornadoes can happen anywhere where conditions are right and they have been observed around the world.

Secondary tornado zones


: A video still of a tornado that touched down in the Russian city of Blagoveshchensk, near the border with China, on July 31, 2011. (Image credit: RussiaToday/YouTube.)

Secondary tornado-prone areas include Canada's prairie provinces, northeastern Mexico, northern Argentina, southern Brazil, Britain, Bangladesh and parts of southern Russia, according to the Storm Prediction Center.

Canadian first

weather, tornadoes, tornado history, safety

A still from a YouTube video that caught an F5 tornado near Elie, Manitoba in Canada on June 22, 2007. (Image credit: YouTube/Justin Hobson)

The first recorded F5 in Canada occurred on June 22, 2007, near Elie, Manitoba.

Round and round

weather, tornadoes, tornado history, safety

A schematic of how tornadoes form. (Image credit: R. Toro, OurAmazingPlanet)

Tornadoes in the Northern Hemisphere tend to spin counterclockwise, though some spin clockwise.

Second season


Storm reports, including tornadoes, for Nov. 22, 2010. (Image credit: National Weather Service Storm Prediction Center.)

A so-called "second tornado season" comes in November in the United States, as fall is a transitional weather time like spring, when warm and cold air masses collide and can create the conditions for tornado formation.

November twisters

oklahoma ef-4 tornado

The biggest November tornado in Oklahoma's history. (Image credit: Steve Grabman/NWS.)

November tornadoes are more common in the lower Mississippi Valley, where the warm air from the Gulf can easily reach.

Not-so-sweet dreams

nocrurnal tornadoes map

A map of the states where nocturnal tornadoes most commonly occur. (Image credit: Walker Ashley/Northern Illinois University)

So-called nighttime tornadoes occur most commonly in the mid-South and Southeast.

Deadly night

Lightning flash seen by the Suomi NPP satellite

A lightning flash from a line of severe thunderstorms sweeping across the eastern United States was spotted from space by the Suomi NPP satellite on the night of Jan. 29, 2013. (Image credit: NASA/NOAA)

Nighttime tornadoes are about twice as likely to kill people as those that occur in the daytime, mostly because people tend to be asleep and not hear sirens and weather radios or be located in unsafe structures like mobile homes.

Be aware of the weather

weather, tornadoes, tornado history, safety

An example of a tornado watch issued by NOAA's Storm Prediction Center. (Image credit: NOAA/NWS/Storm Prediction Center)

A tornado watch means that weather in a particular area could produce tornadoes (often this means thunderstorms are in the area). But it doesn't mean tornadoes will definitely occur.

Be on alert

weather, tornadoes, tornado history, safety

The supercell thunderstorm that produced the tornado that hit Moore, Okla., on May 3, 1999, as it appeared on Doppler radar.

A tornado warning means that a tornado has been spotted on the ground in the area or that the storm circulation seen on Doppler radar could produce a tornado.

Andrea Thompson
Live Science Contributor

Andrea Thompson is an associate editor at Scientific American, where she covers sustainability, energy and the environment. Prior to that, she was a senior writer covering climate science at Climate Central and a reporter and editor at Live Science, where she primarily covered Earth science and the environment. She holds a graduate degree in science health and environmental reporting from New York University, as well as a bachelor of science and and masters of science in atmospheric chemistry from the Georgia Institute of Technology.