<P> South Atlantic tropical cyclones are unusual weather events that occur in the Southern Hemisphere . Strong wind shear, which disrupts the formation of cyclones, as well as a lack of weather disturbances favorable for development in the South Atlantic Ocean make any strong tropical system extremely rare, and Catarina in 2004 was the only recorded South Atlantic hurricane in history . Those storms have developed year - round, with activity peaking during the months from November through May in this basin . Since 2011, the Brazilian Navy Hydrographic Center has started to assign names to tropical and subtropical systems in western side of this basin near Brazil, when they have sustained wind speeds of at least 65 km / h (40 mph), the generally accepted minimum sustained wind velocity for a disturbance to be designated as a tropical storm in the North Atlantic basin . Below is a list of notable South Atlantic tropical and subtropical cyclones . </P> <P> Until April 1991, it was thought that tropical cyclones did not develop within the South Atlantic . Very strong vertical wind shear in the troposphere is considered a deterrent . The Intertropical Convergence Zone drops one to two degrees south of the equator, not far enough from the equator for the Coriolis force to aid development . Water temperatures in the tropics of the southern Atlantic are cooler than those in the tropical north Atlantic . </P>

Hurricanes do not occur in the south atlantic and therefore do not effect cities like rio de janeiro