Why is South America free of hurricanes?

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From June to November, the hurricane season occurs in the Atlantic. However, why do not these natural phenomena reach the south of the continent?

In 2018, the hurricane season reached a record higher than usual, according to the web portal Tiempo, as there were 15 tropical storms, including eight hurricanes, of which two exceeded category 3; the average number of storms is 12. For this reason, 2018 was a different year for the islands of the Atlantic and the Caribbean, the main ones affected in each hurricane season.

Leer en español: ¿Por qué Sudamérica está libre de huracanes?

With those statistics, a question arises: why the countries located in the southern hemisphere of the continent are exempt from any hurricane reaching their lands and affecting everything in its path. According to Minuto Uno, the hurricane season starts in the interval between the end of summer and the beginning of autumn, so cyclones that affect the northern hemisphere occur between the months of May and September, while in the south, these should be generated between January and March.

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Temperature and direction

However, although the south of the continent is currently in the months in which hurricanes form, this phenomenon never develops in there, because it is necessary that the ocean temperature exceeds 26 ℃, something usual in the North Atlantic because of warm currents. For its part, the opening of the South Atlantic towards the Arctic Sea makes it possible that the temperature does not exceed that number, according to the newspaper La Capital.

Another reason is due to the difference in the direction the hurricane takes to form in the Atlantic Ocean. On the one hand, when it forms in the northern part, the winds direct the cyclone towards the west and the hurricane gains force turning counter-clockwise, which causes it to go towards the northern countries. On the other hand, the winds of the South Atlantic blow in the opposite direction, that is to say, to the east, besides that the turn is also the opposite regarding that of the north. Thus, in the hypothetical case of forming a hurricane in the South Atlantic, it would not be directed to the South American countries.

Similarly, although the behavior of hurricanes is unforeseen, this can be evidenced in the Pacific Ocean, near the Central American coasts. In this place, in spite of heading towards the west, sometimes they are directed towards the north, which means that Mexico is the main affected one.

What is expected for 2019

On April 4, the Tropical Meteorology Project of the University of Colorado presented a preliminary report for the hurricane season this 2019, which begins on June 1 and ends on the last day of November. The formation of 13 storms is expected, including five hurricanes and two hurricanes greater than category 3. Nevertheless, these numbers can vary throughout the season, although the University of Colorado has gained fame as far as predictiosn are concerned, because in 2018 it had predicted 14 storms, of the final 15 that occurred.

The hurricane that was out of the parameters

However, all these rules were broken in 2004, when a storm originating in the South Atlantic seemed to become a category 1 hurricane, which affected the coasts of Brazil on March 28. The so-called Hurricane Catarina broke with a fundamental rule: its center had a relatively cold temperature, that is, it did not exceed 26 ℃, according to Astromia. However, it did not cause any serious damage or any victim, since it weakened quickly when touching land.

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LatinAmerican Post | Juan Bacallado

Translated from "¿Por qué Sudamérica está libre de huracanes?"