Análise sinótica de um caso de distúrbio ondulatório de leste sobre a cidade de Natal - RN

Abstract

The purpose of the present case study was to identify an Eastern Wave Disturbance - EWD through synoptic analyzes and its influence on the rainfall observed in the period from June 12nd to 15th, 2014 in the city of Natal, Brazil. For the spatial and subjective identification of the meteorological system, images obtained by the GOES 13 satellite were used with the thermal infrared channel, highlighted with a brightness temperature in ° C from the top of the clouds. Meteorological radar images from the Meteorological Network of the Brazilian Air Force Command – REDEMET - located at the military airport of the city of Natal and data from the rain gauge network of the National Center for Monitoring and Alert for Natural Disasters (CEMADEN) installed in the city were also used. The ERA-Interim reanalysis produced by the European Centre for Medium-Range Weather Forecasts (ECMWF) was used to compose streamline fields, relative vorticity, specific humidity and vertical velocity, all at 850 hPa. It was observed the most intense EWD on June 12nd and 13th with characteristic movements in the northeast-southwest direction, whereas in the days with the higher rain accumulated rate, June 14th and 15th, the movement is characterized by southeast-northwest atypical EWD. The rain associated with the days of direct action of the EWD over the city, 12nd and 13th, generated landslides, floods and material damages. The detection and time evolution of the Eastern Wave Disturbance, performed by compositions applied to the atmospheric variables, and also by the use of direct measurements, were able to allow us a better understanding either the phenomenon and its consequences on the city of Natal