Catarina made landfall in Southern Brazil at peak intensity, with the equivalent of Category 1 hurricane-force sustained winds, on 28 March 2004.

The disturbance was in an unusually favorable environment with a slightly below-average wind shear and above-average sea surface temperatures.

Abnormally favorable conditions persisted, resulting in Catarina intensifying further, and it would peak with 1-minute sustained winds of 137 km/h (85 mph) on 28 March.

The center of the storm made landfall between the cities of Passo de Torres and Balneário Gaivota, Santa Catarina soon after.

Catarina was the first tropical cyclone to make landfall in Brazil since the beginning of reliable records; hence, the infrastructure and population were not specifically prepared for it, which led to severe damage.

Located 630 nautical miles (1,165 km; 725 mi) east-southeast of Florianópolis, it headed slowly westward, and appeared to become a tropical storm on 25 March.

Soon afterward, the hurricane made landfall on the southern coast of Santa Catarina and northeastern Rio Grande do Sul, with winds up to 195 km/h (121 mph) overnight.

After making landfall, Catarina rapidly weakened over land, in the normal manner of a tropical cyclone, dissipating later that day.

[3] Typically, tropical cyclones do not form in the South Atlantic Ocean, due to strong upper-level shear, cool water temperatures, and the lack of a convergence zone of convection.

[4] Catarina remains the only hurricane strength tropical cyclone ever observed in the South Atlantic Ocean (reliable continuous and relatively comprehensive records only began with the satellite era beginning about 1970).

[11] At Passo de Torres, many shipyards were destroyed, as they were not designed to withstand the pressure differentials caused by Catarina's winds; widespread roof damage was reported at this municipality as well.

[12] Many studies were published out to measure Complex post-traumatic stress disorder, its symptoms and depression, focusing on cognition and biological indicators.

[clarification needed] The impact on children is considered particularly difficult to analyze because random assignments and double-blind procedures may not be possible or ethical for them, and therefore studies are usually limited to testing causal hypotheses.

[13] A 2021 study found that the hurricane adversely affected children in utero, leading to reduced birth weight and increases in fetal deaths, possibly due to maternal stress.