Autumn begins with high temperatures in Mato Grosso do Sul and southern Brazil.

Starting next Friday (20), maximum temperatures are expected to rise in western Mato Grosso do Sul and in the southern states of Brazil, persisting throughout the weekend.

The areas most affected by the heat should be Rio Grande do Sul, western Santa Catarina, Paraná and Mato Grosso do Sul, with maximum temperatures expected to reach 38°C on Friday (20) and Saturday (21), exceeding the climatological average for the period in the aforementioned locations. In some specific areas, cities may register maximum temperatures 5°C above the average for the period, especially in the northwest and west of Rio Grande do Sul. Between Saturday (21) and Sunday (22), the presence of instability should temporarily alleviate the heat in these regions. However, from Monday (23) onwards, temperatures will rise again, with the return of even more intense heat conditions.

Figure 1 shows the maximum temperature forecast for next Monday (23). Areas in shades of more intense red indicate where maximum temperatures are expected to be between 36°C and 38°C in western Rio Grande do Sul and Mato Grosso do Sul.

Weather conditions

The formation and persistence of a high-pressure system in the middle and upper levels of the atmosphere, centered between Mato Grosso do Sul and southern Brazil over the next few days (especially between March 20 and 23), inhibits cloud formation in these regions. With the increased incidence of solar radiation, the trend is for intensified warming in these areas.

Since the position of the center of this system oscillates throughout the days and the availability of moisture is restricted to the regions on its edge, this condition will not constitute a heat wave, as isolated rain showers may occur occasionally, momentarily alleviating the feeling of heat.