Tornado
A tornado is a rapidly rotating column of air extending from a cumulonimbus or cumulus cloud to the Earth's surface, characterised by extremely low central pressure, violent winds, and a visible funnel of condensed water vapour and entrained debris. Wind speeds in the most intense tornadoes exceed 480 km/h (300 mph), making them the most destructive wind events on Earth per unit area. Tornadoes form when strong wind shear in a thunderstorm's environment tilts horizontally rotating air into the vertical, creating a rotating updraft called a mesocyclone that can tighten and intensify into a tornado vortex.
Enhanced Fujita (EF) Scale for Tornado Intensity
| EF Rating | Wind Speed (km/h) | Damage Description | Frequency (% of tornadoes) |
|---|---|---|---|
| EF0 (Weak) | 105 – 137 | Minor: broken branches, shallow-rooted trees | ~53% |
| EF1 (Weak) | 138 – 177 | Moderate: mobile homes overturned, roofs damaged | ~32% |
| EF2 (Strong) | 178 – 217 | Considerable: roofs torn off, large trees snapped | ~11% |
| EF3 (Strong) | 218 – 266 | Severe: entire floors of buildings destroyed | ~3% |
| EF4 (Violent) | 267 – 322 | Devastating: well-built homes levelled | ~1% |
| EF5 (Violent) | >322 | Incredible: reinforced structures destroyed | <0.1% |
Interactive Tools
PhET Fluid Pressure and Flow
Explore pressure differentials and flow dynamics related to rotating vortices
Open ToolKhan Academy – Tornadoes
Lessons on tornado formation, the Enhanced Fujita scale, and storm chasing science
Open ToolWolframAlpha Tornado Data
Query tornado statistics, wind speed data, and historical tornado records
Open Tool
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Related Terms
Thunderstorm
A thunderstorm is a local storm produced by a cumulonimbus cloud and characterised by the presence of lightning and thunder, along with strong gusty winds, heavy rain, and sometimes hail. Thunderstorms develop when warm, moist air rises rapidly in an unstable atmosphere through three stages: the cumulus stage (vigorous updrafts), the mature stage (simultaneous updrafts and downdrafts with heavy precipitation and lightning), and the dissipating stage (dominant downdrafts weaken the storm). They are responsible for an estimated 40,000 thunderstorms each day worldwide and play a critical role in redistributing heat and moisture in the atmosphere.
Cold Front
A cold front is the leading edge of a mass of cold, dense air that advances and displaces warmer, lighter air at the surface. As the cold air wedges beneath the warm air, the warm air is forced to rise rapidly, leading to condensation, cloud development, and often intense precipitation. Cold fronts typically bring sudden drops in temperature, gusty winds, and clearing skies after the frontal passage.
Cloud Formation
Cloud formation is the process by which water vapour in the atmosphere condenses onto tiny particles called condensation nuclei to form visible droplets or ice crystals suspended in the air. This process begins when air rises and cools to its dew point temperature, at which point the relative humidity reaches 100% and condensation occurs. The altitude, temperature, and dynamics of the rising air determine the type of cloud that forms, ranging from low stratus to high cirrus clouds.
The word "tornado" is believed to derive from Spanish tronada (thunderstorm), from tronar (to thunder), from Latin tonare (to thunder). The form "tornado" may also be influenced by Spanish tornar (to turn). It entered English in the mid-16th century when Spanish explorers described violent rotating storms encountered in the Americas and West Africa.