Mesoscale convective complexes over the Northeast Brazil and adverse phenomena associated

Abstract

Forecasting of the Mesoscale Convective Complexes (MCC) is extremely important for the Brazilian Northeast’s (BNE) population, as they cause different adverse phenomena such as intense precipitation and thunderstorms causing floods and landslides, provoking social and economic losses. The main purpose of this study is to analyze the MCC development and adverse phenomena associated for the period between 2013 and 2015. The analysis of GOES-13 satellite images in the enhanced infrared channel (IR) were used for the MCC identification. Reanalysis data II of the National Center for Environmental Prediction (NCEP) were used for the synoptic analysis over the streamline fields by the GrADS software. The thermodynamic study was carried out by the plotting of the simulated vertical profiles, with the analysis based on the LI and CAPE + instability indices. Satellite images of the Tropical Rainfall Measuring Mission (TRMM) and data of the Department of Airspace Control (DECEA) were used for the thunderstorms detection. The precipitation detection was collected from the available automatic and conventional stations of the pluviometric stations network of the National Meteorological Institute (INMET). Sixteen MCC cases were identified during the study period and thunderstorm associated was detected in 6 events. Four different synoptic patterns were associated with the MCC formation: Upper Troposferic Cyclonic Vortex (UTCV), Intertropical Convergence Zone (ITCZ), Wave Perturbation on the trade wind and one case was associated with the low-pressure center, classified as the Cyclonic Circulation. For the MCC events with thunderstorms, the obtained CAPE + values of the simulated vertical profiles made it possible to classify the atmosphere as a moderately unstable, while the LI index value presented the possibility of moderate to severe thunderstorms.