Remembering South America's Unusual Tropical Cyclone
March 20, 2009
By WeatherBug Meteorologist, Andrew Rosenthal
Five years ago, one of the rarest events in meteorological history occurred: a hurricane forming in the Atlantic Ocean south of the Equator.
The storm was the first in recorded history to reach tropical storm or hurricane intensity in the South Atlantic Ocean, an area highly unfavorable for tropical development. However, in March 2004, the ingredients came together to create an unprecedented storm that had deadly consequences in Brazil.
Typically, several conditions work against tropical storm formation. Temperatures in the Atlantic south of the Equator remain several degrees colder than those seen to the north, and strong winds in the atmosphere rip a storm apart before it can intensify. Thus, tropical activity is not seen here.
On March 22, 2004, a storm formed that was destined to be unique. A storm system that was sitting along the coast of Brazil developed a wave of tropical moisture and energy that continued to strengthen as it spun offshore. Located about 630 miles offshore in unusually warm water, the storm took on hybrid subtropical characteristics on the 24th. By March 25, the storm was shocking hurricane experts around the world as it turned tropical.
The storm continued to strengthen as it slowly moved westward toward the Brazilian coast, developing an eye and a strong structure observed by satellite. Being south of the Equator, it was a mirror image of a hurricane and spun clockwise.
The storm slammed into Torres, in the Brazilian state of Santa Catarina on March 28. As this area had never experienced a hurricane before, damage was immense. The storm`s 100 mph winds collapsed nearly 1,500 buildings, destroyed 85 percent of the banana crop and killed three. Storm damage was estimated at about $350 million.
The storm had no official name as the world`s hurricane-naming group did not create a list of storm names for the South Atlantic. Unofficially, the storm became known as Catarina as a tribute to the state that it inflicted damage.
Although the storm came and went 5 years ago, hurricane experts still debate what caused this storm to form, and the odds of another forming again in the future. The storm, however, is proof that a hurricane can happen in some unexpected tropical places.
Story Image: NASA`s Aqua satellite captured this image of the cyclone as it approached the coast of Brazil. (Courtesy MODIS Land Rapid Response Team, NASA GSFC)
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