tornadoes

Tornadoes are violently rotating columns of air that extend from a thunderstorm to the ground. They typically form in highly organized storms, especially supercells, where strong wind shear and a rising, rotating updraft create a mesocyclone. A funnel cloud may appear as the visible sign of rotation, but a tornado is defined by contact with the ground.

Most tornadoes are relatively small and short-lived, but they can be exceptionally powerful. They vary in size from a few meters to over a kilometer in width and can travel several kilometers to over 100 kilometers. The strength of a tornado is usually assessed after damage occurs, using the Enhanced Fujita scale, which ranges from EF0 (weak) to EF5 (incredible). Wind estimates are inferred from the observed damage rather than measured directly.

Tornadoes occur worldwide but are most common in the United States, particularly in the central Plains area known as Tornado Alley. They also appear in Canada, parts of Europe, Australia, and Asia. Seasonal and regional patterns vary, with spring and early summer peak in the southern Plains and later peaks in other regions.

Forecasting and warnings rely on meteorological observations, Doppler radar, and atmospheric models. Watches indicate favorable conditions; warnings are issued when a tornado is detected or strongly suspected. Public safety relies on immediate action when warnings are in effect.

Impacts include property damage, injuries, and fatalities, along with environmental disturbance from debris and soil movement. Preparedness, early warning, and prompt protective action reduce risk.