Diagnostic study and numerical simulation of the Bombay (India) Deluge

Abstract

Bombay (latitude: 19.1°N, longitude: 72.9°E, altitude: 14 m asl) received unprecedented amount of rainfall, 94.4 cm in 24 h, from 26 to 27 Jul 2005. Observational and model simulation, based on Advanced Regional Prediction System, study of this extreme event is made. The thermodynamical assessment is made using vertical sounding in model simulation. Artificial thermal perturbation is introduced to initiate the instability for generation of vertical convection with assumption that convection is initiated due to the thermal forcings and neglecting the effect of mechanical perturbation (orographic forcings). Model could simulate the thermal nature of the storm as observed. Also, simulation shows the vigorous nature of thunderstorm with heavy downpour at the rate of 10 cm/h, which is close to the observed.