This first pulse led to the development of several equatorial Rossby waves – the formations of Cyclones Vicky and Waka were related to these waves.
The geographical distribution of Mediterranean tropical cyclones is markedly different from that of other cyclones, with the formation of regular cyclones centering on the Pyrenees and Atlas mountain ranges, the Gulf of Genoa, and the island of Cyprus in the Ionian Sea.
This implies that El Niño substantially increases the movement toward the extremes of heat-moisture energy and impacts high latitudes via changing the formation of tropical cyclones and their trajectories.
In the Northwestern Pacific, El Niño shifts the formation of tropical cyclones eastward.
The formation of tropical cyclones is the topic of extensive ongoing research and is still not fully understood.
Due to the dry nature of the Mediterranean region, formation of tropical cyclones is infrequent, with only 100 recorded tropical-like storms between 1948 and 2014.
The baroclinic properties of the Mediterranean region, with high temperature gradients, also provides necessary instability for the formation of tropical cyclones.
Although the geography of the Mediterranean region, as well as its dry air, typically prevent the formation of tropical cyclones, when certain meteorological circumstances arise, difficulties influenced by the region's geography are overcome.
The South Atlantic environment for formation of subtropical cyclones has both stronger vertical wind shear and lower sea surface temperatures, yet subtropical cyclogenesis is regularly observed in the open ocean in the South Atlantic.
