A Comparison of Subtropical Storms in the South Atlantic Basin with Australian East-Coast Cyclones

Tropical storms have long been thought to occur in every ocean basin in the world, excluding the South Atlantic; however, in March 2004, Hurricane Catarina changed this assumption. Hurricane Catarina developed due to the evolution of a subtropical storm into a hurricane. In fact, this study will demonstrate that many subtropical storms have formed within the South Atlantic basin within the last 40 years. These storms are important to document due to their destructive nature caused by gale-force winds and intense rainfall.

A climatology of subtropical storms within the South Atlantic Basin will be presented. South Atlantic subtropical cyclones behave and appear as their North Atlantic counterparts, some fraction of which have been shown to continue their development to become hurricanes. The subtropical storms documented within the South Atlantic reveal remarkable similarities to Australian east-coast cyclones, developing under similar meteorological conditions. The correlation between these two basins has spectacular implications for how subtropical storms fit into the climatology of the South Atlantic basin.