Frosts weaken, but persist in the South and Southeast.

The low temperatures prevailing in southern Brazil have favored the occurrence of frost over the past two days due to the presence of a cold, dry air mass that moved into Brazil after the passage of a cold front. However, the forecast from the National Institute of Meteorology (Inmet) indicates a gradual reduction in the areas experiencing frost in the coming days, as the cold air mass loses intensity and minimum temperatures gradually rise.

In the early hours of Wednesday (July 8th), 12 weather stations recorded sub-zero temperatures, and a total of 41 stations observed temperatures equal to or below 3°C, the lowest being -2,7°C in General Carneiro (PR). These conditions favor the formation of frost in several locations, especially in low-lying areas, plateaus, and mountain ranges.

Data from weather stations show that there was an increase in the area affected by the cold this Wednesday (7/8) compared to Tuesday (7/7), when only five stations, all located in Rio Grande do Sul, recorded negative temperatures.

This scenario is a consequence of a mass of cold, dry air that advanced over the Central-South region of Brazil in the wake of a cold front in recent days. With predominantly clear skies, weaker winds, and lower humidity levels during the early morning hours, there was intense radiative cooling, associated with cloudless conditions, which favors a sharp drop in temperatures and the formation of frost across much of the Southern Region.

Forecast for the next few days (Thursday and Friday)

Despite the continued possibility of more localized frosts, the forecast indicates a gradual reduction in areas experiencing frost, as the cold air mass loses intensity and minimum temperatures gradually rise. Furthermore, areas of instability originating from Paraguay are expected to move over southern Brazil starting on Friday (July 10th), which should change weather conditions and bring rain to the southern states during the weekend of July 11th and 12th.

In the early hours of Thursday (July 9th), conditions favorable to frost formation, with a potential risk warning, are expected to prevail in northern Rio Grande do Sul, much of Santa Catarina (except the coastal strip), south-central and eastern Paraná, as well as the mountain areas located on the border between Minas Gerais, São Paulo and Rio de Janeiro.

On Friday, conditions for frost formation will decrease even further. The forecast indicates that the phenomenon should be restricted to the higher altitude areas of the Serra da Mantiqueira mountain range, especially on the border between the states of Minas Gerais and São Paulo, where temperatures may still reach values ​​around 0°C.