Strong to severe storms with medium to large hailstorms hit in the last hours points in the Center of Argentina and Uruguay, just as it had been alerted by MetSul. From the afternoon to the night of Sunday (12) and at dawn this Monday (13) intense areas of instability associated with a low pressure center formed between the Argentine Northeast, the Uruguay and Rio Grande do Sul with clouds of great vertical development.
Very hot air is now advancing through the interior of the continent and favors the intensification of instability in the region. The temperature in mid-morning this Monday was already at 35ºC at Asunción Airport, in Paraguay, which is a very high mark for the time, indicating the strength of the hot air that is “feeding” the storms further south.
The very heated atmosphere provides the energy for the formation of clouds of great vertical development, whose tops between 15 and 20 kilometers in altitude reach a temperature of -70ºC to -80ºC, which provides greater hail.
Intense areas of instability formed between Sunday afternoon and evening between Uruguay and southern Rio Grande do Sul, bringing the first occurrences of hail in Uruguayan territory. At dawn today, new and strong areas of instability have originated in the Northeast of Argentina and in the west of Rio Grande do Sul with new strong storms in the region.
TIME | Animation of satellite images from the last 10 hours shows that strong storm areas formed at the end of Sunday between Uruguay and the south of the state, and new and intense storm areas appear at dawn in the west of the state, with a tendency to move to the east and south. pic.twitter.com/XHP2gsX0P5
— MetSul.com (@metsul) September 13, 2021
Spring is a period of many storms in the mid-latitudes of South America with the interaction of warm air with low pressure centers and the frequent encounter of hot and cold air masses, conditions that favor the occurrence of frequent storms of strong wind and hail in the region. This early week’s storms, therefore, are within what might be expected at this time of year.
MetSul maintains the warns that another round of very strong storms is possible this afternoon to tonight between the Northeast of Argentina, Uruguay and Rio Grande do Sul. This is because the cloudiness decreased with the presence of the sun and the entry of very hot air in Argentine provinces such as Santa Fé, Entre Rios, Corrientes and Misiones, as well as part of the West and of the Northwest of Rio Grande do Sul.
With the very high temperature and extremely unstable atmosphere, new areas of very intense instability capable of bringing hail in many cities should explode, as well as isolated episodes of intense to locally destructive wind with high volumes of rain in a short period and many lightning strikes.