Tracing Pre-Tropical Cyclone African Easterly Wave-Mesoscale Convective Systems over African Continent

In this study, the African easterly waves (AEWs) and their embedded mesoscale convective systems (MCSs) serving as precursors for the major hurricanes over eastern Atlantic Ocean were traced back to African continent. As pointed out in a previous study, a significant number of major hurricanes was initiated by AEW originated to the eastern North Africa. Thus, in this study we focus on hurricanes and tropical storms formed in the just west of Africa (30-40E, 5-15N) from 2000 to 2008. Based on Meteosat infrared imagery there were convective systems associated with all the hurricanes and storms observed moving across the continent.

The propagation of the disturbances all showed characteristics of AEWs. Reanalysis data and GRADS were used to prove that the MCSs observed were indeed associated with AEWs and most of them were originated from eastern Africa, as far as Ethiopian Highlands. The simulations by global model (GFS) showed propagating waves and convection over Africa. The simulated waves also showed similar tracks and characteristics to the purposed AEWs of the disturbances.