Tornadoes, explained.
A spinning column of air, reaching from a thunderstorm to the ground. They happen across the USA, and in the UK and Europe too. Every fact here is checked against NOAA’s Storm Prediction Center and Severe Storms Laboratory, the Met Office, TORRO and the European Severe Storms Laboratory. Build your own tornado, rate them on the EF scale, and meet Useless, an eraser tracking storms from a desk drawer.
Build a tornado
Pick the four ingredients, then press Grow the storm. Get every one right and your thunderstorm becomes a rotating supercell, and maybe a tornado. Get one wrong and nothing happens, and you’ll find out why. Then cut off its warm air and watch it die away.
Every ingredient and stage comes from NOAA’s National Severe Storms Laboratory, the Storm Prediction Center or the Met Office (sources shown in the game). The pictures and timings are made up by the game; real storms are far less predictable. Scientists say the honest answer to “how do tornadoes form?” is that we don’t fully understand. NOAA NSSL: Tornado basics
The short version
A tornado is a narrow, violently rotating column of air that reaches from a thunderstorm down to the ground. NOAA NSSL: Tornado basics By definition, a tornado must touch the ground and a storm cloud at the same time. So “tornado on the ground” says the same thing twice. NOAA Storm Prediction Center: The online tornado FAQ
Most tornadoes come from supercells: thunderstorms with a rotating updraft. NOAA NSSL: Types of tornadoes As few as 20 per cent of supercell thunderstorms actually produce a tornado. NOAA NSSL: Types of tornadoes
Tornado wind speeds are rarely measured directly. Experts look at the damage and work out what wind speed must have caused it. NOAA NSSL: Tornado basics The Enhanced Fujita (EF) scale, an update by meteorologists and wind engineers, came into use in the USA on 1 February 2007. NOAA Storm Prediction Center: EF scale wind speeds
The best place in a building is the most interior room on the lowest floor, with no windows: below ground if possible. NOAA Education: Tornadoes
Explore tornadoes
What is a tornado?Funnels, subvortices and why there’s no eye.
How tornadoes formFour ingredients and four stages.
Waterspouts & moreLandspouts, gustnadoes and dust devils.
The EF & TORRO scalesHow experts rate a tornado from its damage.
Where they happenTornado Alley, Argentina, Bangladesh and beyond.
The UK & EuropeAround 30 a year in the UK, and a record outbreak.
Watches & warningsWhat they mean and where to shelter.
Radar & spottersHook echoes, mobile radar and SKYWARN.
Records & historyThe Tri-State Tornado, El Reno and more.
Tile images are credited on their pages and on the credits page.
Things to play
- Build a tornadoPick the four ingredients and watch a supercell grow, or fizzle.
- EF CatcherA damage survey team estimates the wind. You give the EF rating before the next tornado crosses the field.
- Tornado Ready DashReal situations, against the clock. Watch or warning? Where do you go?
- Tornado QuizTen questions at a time. Every answer comes with its source.
- Tornado PairsA memory game with real NOAA pictures.
Enjoying the storm? Help keep this site going.
This site is hand-built, fact-checked and free to read. If a fact, a game or one of Useless’s notes made you smile, a little support keeps it going and helps the network grow.
Tornado printables
Fact-checked PDFs in A4 and US Letter, sold as instant downloads from the ReallyByte store.
Tornado Science Pack
The four ingredients, the four stages, label a supercell, tornado or not, the UK and the world, watch-or-warning sorting and a family tornado plan, with answer keys
EF & TORRO Scale Maths Worksheets
Rate tornadoes on the EF scale, convert mph, km/h and metres per second, use the TORRO and Beaufort link and work with real records, with answer keys
How Tornadoes Work Cards
Twelve double-sided cards, from the four ingredients to the radar truck, plus a put-it-in-order game
Tornado Activity & Colouring Pack
Colouring scenes, a get-to-the-shelter maze, a word search and puzzles for ages 4 to 9
Tornado Quiz & Word Puzzles Pack
A crossword, code breaker, fill-the-gap facts, number match, myth busters and a 16-question quiz, with answer keys
Best valueThe Complete Tornado Printables Bundle
All six packs plus a guide, A4 and US Letter, in one download.