Tornado hits the interior of Rio Grande do Sul; understand what happened

A tornado hit the rural area of ​​the municipality of São Martinho da Serra, in the center of Rio Grande do Sul, on Saturday. Residents of the region filmed the tornado advancing over crops and passing through the headquarters of a rural property, where it caused damage.

The tornado occurred on a day of enormous atmospheric instability in Rio Grande do Sul with the movement of a cold front through the state that brought heavy to intense rain with volumes of up to 200 mm on the border with Uruguay, hail and some isolated gales. , like in Santa Cruz do Sul, which had hundreds of roofed houses.

According to meteorologist Estael Sias, the atmospheric conditions were very conducive to the formation of this type of phenomenon. “We observed in the morning on satellite images how the instability over the state presented the shape of the letter ‘v’ inverted, which is characteristic of great divergence in the atmosphere”, she comments.

Estael Sias highlights that a low-level jet stream acted over Rio Grande do Sul and was responsible for a strong north wind during Saturday morning in Santa Maria and intense heat of 34ºC in the Northwest during the afternoon.

“When a jet stream at low levels, a strong wind corridor between 1000 and 1500 meters of altitude, is acting and there is the advance of a cold front, a situation is created in which winds blow in divergent directions in the lower part of the atmosphere and this favors the formation of tornadoes”, he explains.

“For this reason, the overwhelming majority of times tornadoes were recorded in Rio Grande do Sul there was the presence of a jet stream at low levels of the atmosphere”, adds the MetSul meteorologist.

The tornado’s passage through the rural area of ​​São Martinho da Serra left no injuries. The damage was concentrated in a rural establishment, where the strong wind associated with the tornado caused the roofing of a shed and other minor damage.

Tornadoes are extreme and destructive meteorological phenomena characterized by intensely rotating columns of air that extend from the base of a storm to the Earth’s surface. These violent whirlpools are known for their devastating capacity, capable of causing great destruction in seconds to minutes.

The Fujita scale, often used to rate the intensity of tornadoes, ranges from F0 to F5, with F5 being the most powerful. Tornadoes often form in areas where masses of warm, moist air meet masses of cold, dry air, creating ideal conditions for these vortices to develop.

Tornadoes occur in many parts of the world, including Australia, Europe, Africa, Asia and South America. Even New Zealand reports about 20 tornadoes per year. Two of the highest concentrations of tornadoes outside the United States are in mid-latitude South America and Bangladesh.

About 1,200 tornadoes hit the United States annually. Because official tornado records only date back to 1950, the actual average number of tornadoes that occur each year is unknown. Furthermore, methods of detecting and reporting tornadoes have changed a lot in recent decades, which means that statistics now consider tornadoes that in the past would not be included in the accounting. Brazil does not have a robust database on these occurrences in the country throughout history and verification and event accounting projects are incipient.

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