Plain English Meaning

Bumpy, unsettled air. Instead of flowing smoothly, the air is moving in jumbled pockets that push the airplane around.

Full Definition

Irregular motion of the atmosphere caused by air moving in eddies, currents, or sudden vertical and horizontal gusts. Turbulence is reported in four intensity categories — light, moderate, severe, and extreme — based on the effect it has on the aircraft and its occupants.

Context Anchor

Pilots encounter turbulence in weather briefings, pilot reports, forecasts, near mountains, near storms, close to the ground on windy days, and behind other aircraft.

Derivation

From the Latin 'turbulentus,' meaning 'restless' or 'disturbed,' from 'turba' meaning 'crowd' or 'commotion.' The image is of air that is stirred up and disorderly rather than flowing in a smooth, stream.