Definition
In turbulence reporting, a category indicating turbulence in which the aircraft is violently tossed about and is practically impossible to control. It may cause structural damage.
Plain English
The most severe level of turbulence on the reporting scale. The airplane is thrown around so badly that the pilot cannot keep it under control, and the airframe itself may be damaged.
Context Anchor
Seen in pilot weather reports, weather briefings, and air traffic control reports that describe turbulence intensity.
Derivation
From Latin extremus, meaning 'outermost' or 'farthest.' In aviation turbulence reporting, it marks the far end of the scale — beyond Severe, with nothing worse defined.
Why Pilots Care
Signals conditions that may require immediate diversion or landing to avoid loss of control.
Intuition Check
Extreme does not just mean “very bumpy” or “uncomfortable” here. In FAA use, it means the highest turbulence intensity, where control may be nearly impossible and the aircraft may be damaged.
Example Sentence 1
The crew reported extreme turbulence over the mountains and requested an immediate descent and route change.
Example Sentence 2
Extreme conditions in the thunderstorm prompted the controller to reroute all traffic.