THE CLIMATIC GENESIS OF TORNADOES IN THE STATES OF THE SOUTHERN REGION OF BRAZIL AND SÃO PAULO

Abstract

Tornadoes are intense and extreme atmospheric events, being one of the most difficult natural disasters with anticipating forecasting. So, this research concerned in to analyze the regional atmospheric circulation involved in the genesis of this phenomenon in the Southern Region of Brazil and in the state of São Paulo. The methodology used was based on bibliographic review, description of the study area, construction of a database of tornado records between 1959 and 2018, and the use of synoptic charts of the Brazilian Navy and INPE satellite images, on the day of each event to identify the active atmospheric system. The analysis of the database showed an increase in the number of records after the 1990s, with a peak between 2006 and 2009. It can be conclude that the atmospheric system with the greatest participation in the genesis of tornadic events for the study area was the Atlantic Polar Front, accounting for 38.4% of all 138 tornadoes records. Finally, the analysis of the seasonality of tornadoes records showed that events occur mainly in the spring and summer months, totaling 59.4% of the cases together.