How the weather has changed since the phenomenon

20 years ago, on March 28, 2004, a Sunday, Brazil woke up to the impact of the news of a hurricane that had made landfall during the early hours of the morning in southern Brazil. with death and destruction. The storm hit the South of Santa Catarina and the North Coast of Rio Grande do Sul, but even in Porto Alegre and Serra there was wind damage.

The hurricane, named Catarina by the Santa Catarina state meteorological center (Ciram), was responsible for hundreds of millions of reais in losses and a dozen deaths. One special report by Correio do Povo told how the horror scenes remain alive in the memory of those who witnessed the phenomenon.

O Hurricane Catarina was the first and only hurricane documented to date in the South Atlantic and had intensity between the upper limit of category 1 and the lower limit of category 2 on the Saffir-Simpson scale with sustained wind around 150 km/h and stronger gusts.

Catarina was a shock for Meteorology, the world and especially for Brazilian professionals. How could a hurricane have formed if scientific theory stated that it was not possible over the South Atlantic?

Although it was evident to MetSul and other professionals even before the storm made landfall, months of debates ensued in Brazilian Meteorology to classify the phenomenon. The conclusion, heard by experts from abroad, was obvious: it was a hurricane.

Chronology of Hurricane Catarina
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20 years after Catarina, no other hurricane has formed in the South Atlantic regionalthough tropical storms, the stage before a hurricane, have originated off the coast of Brazil in recent years.

For MetSul, the 2004 disaster forced changes, but not everything was progress. Today, two decades later, there is greater knowledge about tropical cyclones in Brazil and a much better capacity for numerical forecast modeling and monitoring tools, largely of foreign origin. Even a list of names was designed to designate atypical, subtropical and tropical cyclones (a hurricane is a tropical cyclone).

Santa Catarina’s Civil Defense, for example, was structured and became an example of the best among the three southern states. There is an even greater culture of alerts and a greater capillarity of warnings with the advancement of social networks, even today, as in 2004, many people do not take the warnings seriously or disbelieve the predictions.

On the other hand, MetSul remembers that the monitoring buoys on the coast, so mentioned in 2004, are almost nil. “We still do not know what happens in the open sea before a cyclone makes landfall, with only satellite wind estimates available (already in 2004) and sparse reports from vessels. Furthermore, building codes in coastal cities, which are also affected by extratropical cyclones, a recurring phenomenon and also capable of causing destructive winds, have never been adapted to the risks of very intense to extreme wind on the coast.”

According to MetSul, Brazil is mistaken when it centralizes warnings and information about atypical cyclones in the Navy’s meteorological service, which has exclusive concern and legal competence for the oceans, when these systems often cause impacts on dry land, where people live. (more than half of the Brazilian population lives close to the coast). The Navy bulletins are unintelligible to the population, who are unaware of the Beuafort wind scale, for example, and focus on maritime safety and not on the preservation of lives and property on the continent. In MetSul’s view, the primary competence for forecasting these cyclones should lie with the National Institute of Meteorology, which is the official weather forecasting body in Brazil, and should have a specialized unit for forecasting cyclones, which could be done in partnership with other regional services such as those in Uruguay and Argentina.