Study of severe rainfall events occurring in 2009 in the state of pará

Abstract

The importance of weather forecasts for very short periods of time (nowcasting) has increased in recent years due to the considerable increase in natural disasters such as floods, landslides, wind gusts, etc. In this context, the use of weather radar equipment has great operational utility in the detection and monitoring of adverse short notice meteorological phenomena. The metropolitan region of Belém (RMB) is one of the most populous regions of the Amazon. In recent years unplanned urban occupation is taking place, being probably one factor that causes troubles for the population that suffers due to downpours and flooding. The 2009 year extreme events were identified and analyzed using the TITAN (Thunderstorm Identification, Tracking, Analysis and Nowcasting). The results show that 66% of severe events have occurred during the rainy season, which was due to three major weather systems: the Intertropical Convergence Zone (ITCZ), its interaction with the South Atlantic Convergence Zone (SACZ) and Squall Lines (LI) originated mostly from the sea breeze. The results also show that smaller-scale systems, like the lines, have higher severity because they cause higher rates of hourly precipitation. © 2014, Sociedade Brasileira de Meteorologia. All rights reserved.