A tornado devastated Rio Bonito do Iguaçu, in Paraná, on Friday (7), with winds above 250 km/h. The phenomenon emerged from a supercell and lasted minutes, destroying local structures. An extratropical cyclone affects the South and Southeast of Brazil this Saturday (8), with winds of up to 100 km/h and intense rain.
Experts from Cemaden and Climatempo explain the distinctions between these meteorological events. The phenomena differ in formation, extent and duration, with no direct relationship between them.
- Tornadoes: small and intense, with a diameter of up to 1 km.
- Extratropical cyclones: broad, up to 1 thousand km wide.
- Hurricanes: tropical cyclones in warm oceans.
Scale and duration of phenomena
Tornadoes occupy small areas, rarely exceeding 1 km in width. They dissipate quickly, within seconds to minutes.
Extratropical cyclones cover extensive regions, like a thousand kilometers. Its action persists for days, influencing multiple states.
Hurricanes cover areas equivalent to entire states. They remain active for prolonged periods over oceans.
Recorded wind power
Winds in tornadoes exceed 250 km/h, causing localized and intense damage. Rotation occurs in descending funnel clouds.
Extratropical cyclones generate winds of up to 150 km/h at maximum. They result from contrasts between hot and cold air masses.
Hurricanes have winds above 119 km/h, with strong horizontal rotations. Energy comes from ocean waters above 27°C.
Specific training for each type
Tornadoes emerge from severe storms with mesocyclones. Charged supercells favor their occurrence in unstable areas.
Extratropical cyclones develop in mid-latitudes. Low atmospheric pressure attracts air of varying temperatures, forming clouds.
Hurricanes, or tropical cyclones, start near the Equator. Hot waters provide steam for intensification.
Occurrence in national territory
Tornadoes recorded at least 205 cases between 1990 and 2011, according to a study by Unicamp. Events increase with climate variations.
Extratropical cyclones occur frequently in southern Brazil. The influence of El Niño intensifies storms in the season.
Hurricanes do not form in the South Atlantic due to unsuitable conditions. Subtropi casespiers are rare and less powerful.
Classification by measured intensity
The Enhanced Fujita scale evaluates tornadoes from F0 to F5. Damage in Rio Bonito do Iguaçu indicates high category.
Extratropical cyclones do not use this specific metric. Impacts involve rain and winds across a wide region.
Hurricanes follow the Saffir-Simpson scale, from 1 to 5. Speeds define categories based on potential damage.
Climatic factors involved
Thermal contrasts between cold and warm fronts generate instability. Severe thunderstorms precede tornadoes in the Central-South.
Climate change increases extreme events across the country. Frequency of intense rains and strong winds increases.
Civil defenses issue alerts for Rio Grande do Sul, Santa Catarina, São Paulo and Rio de Janeiro. The population receives guidance on risks.
