Turbulence -

Crucial because "severe" turbulence for a small Cessna might only be "light" for a large Airbus A380 .

Whether the turbulence occurred in clouds or clear air (CAT). 2. Intensity Classifications turbulence

Occupants forced violently against belts; walking is impossible. Crucial because "severe" turbulence for a small Cessna

A standard pilot report ( PIREP ) for turbulence must include several critical data points to ensure air traffic control (ATC) and other aircraft have a clear picture of the conditions: turbulence