We see tropical cyclones (going by different names e.g. hurricane, typhoon, cyclone) all over the tropics, but it seems that there are never any storms in the southern Atlantic. See this map of tropical cyclone activity and note the lack of activity in the south Atlantic and also in the south Pacific until you near Australia.
Where are all the tropical cyclones in the southern Atlantic basin?
There have been tropical storms and hurricanes in the south Atlantic, with, according to NOAA's webpage Subject: G6) Why doesn't the South Atlantic Ocean experience tropical cyclones?, with a hurricane forming in the south Atlantic making landfall in Brazil in 2004 and a strong tropical depression/weak tropical storm that formed off the coast of Congo in 1991 - but these are exceedingly rare.
The reason why these storms generally don't occur in the south Atlantic, according to the Penn State webpage Upper-level Lows as being:
There are two primary reasons why tropical cyclones are rare in the south Atlantic basin. First, vertical wind shear between 850 mb and 200 mb is typically greater than 10 meters per second (check out the long-term average of vertical wind shear between 850 mb and 200 mb). To make matters worse, westerly shear dominates over latitudes where tropical cyclones would be most likely to form. Second, easterly waves from Africa do not form south of the equator (the MLAEJ is a northern hemispheric singularity.
Further, from the NASA News page The Nameless Hurricane, they provide an extension to the explanation with
Vertical wind shears in the south Atlantic are too strong for hurricanes," Hood explains. Winds in the upper troposphere (about 10 km high) are 20+ mph faster than winds at the ocean surface. This difference, or shear, rips storms apart before they intensify too much
An article The first South Atlantic hurricane: Unprecedented blocking, low shear and climate change (Pezza and Simmonds, 2005) suggest that the implications of the southern hemisphere hurricane presents
evidence to suggest that Catarina could be linked to climate change in the SH circulation, and other possible future South Atlantic hurricanes could be more likely to occur under global warming conditions.
Catarina refers to the southern hemisphere hurricane
SH = Southern Hemisphere
edited to add an NASA Earth Observatory satellite image of the hurricane:
The original question asked why there were no hurricanes in the southern hemisphere. The answer given:
It really is just a naming convention based on location. You can see in the wikipedia article here: http://en.wikipedia.org/wiki/Tropical_cyclone#Classifications.2C_terminology.2C_and_naming , it says:
Tropical cyclones are classified into three main groups, based on intensity: tropical depressions, tropical storms, and a third group of more intense storms, whose name depends on the region. For example, if a tropical storm in the Northwestern Pacific reaches hurricane-strength winds on the Beaufort scale, it is referred to as a typhoon; if a tropical storm passes the same benchmark in the Northeast Pacific Basin, or in the North Atlantic, it is called a hurricane. Neither "hurricane" nor "typhoon" is used in either the Southern Hemisphere or the Indian Ocean. In these basins, storms of a tropical nature are referred to as either tropical cyclones, severe tropical cyclones or very intense tropical cyclones.
... each basin uses a separate system of terminology, which can make comparisons between different basins difficult. In the Pacific Ocean, hurricanes from the Central North Pacific sometimes cross the 180th meridian into the Northwest Pacific, becoming typhoons (such as Hurricane/Typhoon Ioke in 2006); on rare occasions, the reverse will occur.
