March is set to usher in intense and sustained heat across various regions of Brazil, particularly as it transitions from summer to autumn. The month begins with meteorological predictions indicating elevated temperatures, with some areas expected to reach as high as 40°C. This heatwave is expected to influence several states, including Rio Grande do Sul, Santa Catarina, São Paulo, and Rio de Janeiro.
According to Guilherme Borges, meteorologist from Climatempo, the early days of March will experience above-normal temperatures due to the influence of a new heatwave. “It’s going to be a really hot start to March,” he declared, emphasizing the risks associated with such extreme conditions.
Indeed, the southern region, particularly Rio Grande do Sul, has been warned of oppressive temperatures rising sharply, with thermometers potentially nearing 40°C, especially around the metropolitan area of Porto Alegre and along the valleys of the Rio Pardo and Taquari. This typical summer heat is forecasted to last until at least mid-March when some cooling trends are expected to set in.
This upcoming warm spell follows months where many meteorological events and climatic conditions influenced local weather patterns. Notably, January saw slightly cooler sea surface temperatures off the coast, indicating La Niña conditions which have affected rainfall and storm phenomena throughout Brazil. With La Niña losing its grip, the climate is projected to become neutral, which may lessen its immediate impact but still leaves many regions bracing for erratic weather patterns.
Further, the forecast points to below-average rainfall for March. According to various meteorological sources, including the Epagri/Ciram, long periods without precipitation are anticipated, especially impacting regions like the West of Santa Catarina. Rainfall is expected to total between 100 to 130mm for the West and Planalto regions, with coastal areas seeing between 150 to 210mm.
Despite the expected dry conditions, the potential for severe climatic events remains high. The close of summer and onset of autumn can trigger short, intense storms. Severe weather, including hail, lightning, and high winds, is also likely, particularly as cyclones are anticipated to affect parts of southern Brazil.
Taking all of this data together, meteorologist Gilsânia Cruz warns about the possible frequency of intense climate events. “From March onward, extratropical cyclones may act more frequently along the coast of Uruguay, Rio Grande do Sul, and Santa Catarina,” she cautioned.
Looking at specific regional forecasts, the National Institute of Meteorology (INMET) suggests the south will experience rainfall below average, amid persistent warmer conditions. While rainfall expectations remain low, sporadic instances of rain will contribute to fluctuations in temperature, providing some respite as March progresses.
Interestingly, forecasts for lower rainfall do not equate to evenly distributed precipitation. Instead, rain may be accompanied by abrupt changes, with the possibility of isolated thunderstorms as atmospheric conditions fluctuate,” mentioned Glauco Freitas, another meteorologist.
The predictions point to the first two weeks of March experiencing temperatures 3°C to 7°C above seasonal averages before transitioning to more typical temperatures as the month advances. A slight decline is expected around March 10, coinciding with the approach of autumn on March 20.
Despite the lesser rain totals, regions like Paraná are also set to see highs reaching 37°C early this month. Although dry conditions will dominate, some showers can be expected later, particularly as autumn begins to take hold.
Overall, each part of Brazil is expected to face different challenges this March, marking both the transition to cooler months and the potential for severe weather events. The focus on weather updates from meteorological agencies will be more important than ever to prepare for whatever March has to offer.