Figure 1: Tracks of all AEWs associated with cyclones (48 developing AEWs). These tracks are obtained by following the maxima of relative vorticity at 850 hPa associated with AEWs troughs. For each cyclone, maximum of relative vorticity is tracked from the genesis day of the cyclone to Africa until this value is less than  s−1. Genesis dates of cyclones are obtained from the NHC Best Track.