The weekend will have thunderstorms and large volumes of rain in the South Region

This Friday (27), the weather becomes highly unstable again in areas of the Southern Region of Brazil, especially between the northwest/north of Rio Grande do Sul and the west and mid-west of Santa Catarina, with conditions for thunderstorms, accompanied by of gusts of wind and possible hail in some parts of these areas. During thunderstorms, wind gusts can exceed 90 km/h.

The advancement of a trough (elongated area of ​​low pressure) at high levels of the atmosphere will favor the deepening of a new area of ​​low pressure at the surface, a pattern that, combined with the advancement of shortwave troughs at medium levels of the atmosphere (approximately 5.000 meters altitude) and the intense flow of hot and humid air coming from the north (low-level jet), will maintain strong instability on Saturday (28).

On that day, the storms are expected to spread to other areas of Santa Catarina and Paraná. The forecast indicates large volumes of rain, with 24-hour totals greater than 100 millimeters (mm), especially in the north of Rio Grande do Sul and in parts of the west and south of Santa Catarina (left figure). On Sunday (29), the largest volumes of rain will be concentrated between Santa Catarina and Paraná.

Furthermore, in the coming days, there are conditions for thunderstorms between Mato Grosso do Sul, São Paulo, southern Minas Gerais and Rio de Janeiro.

At the beginning of next week, the tendency is for areas of instability with conditions for storms to persist in the southern portion of the country. As a result, rainfall accumulated in seven days could exceed 300 millimeters in some locations (right figure).