An aim of the invention is to allow the detection of turbulence in the absence of tracers. A radar is embedded aboard an aircraft (21) and implements the following steps: searching for the upper part of a convective system (1) situated outside the given zone, reflecting the electromagnetic waves; searching for divergence zone (7) inside the convective system by searching for a divergence profile; reckoning the appearance of turbulence in the given zone as a function of observable meteorological phenomena in the divergence zone (7) by applying fluid mechanics properties.