NUMERICAL SIMULATION OF A SEVERE THUNDERSTORM OVER DELHI USING WRF MODEL

Abstract

A severe thunderstorm affected Delhi and adjoining region between 1630 hrs 1ST and 1730 hrs 1ST of 30ht May 2014. The system moved eastward and was steered by westerly trough. It propagated through U.P, Bihar and dissipated over West Bengal on 31" May 2014. This event was accompanied by strong winds, lightening, thunder, rainfall & hail and resulted in loss of property, life and also aviation hazards. In this study Weather Research Forecasting (WRF) system version 3.6.1 has been used to simulate and investigate the severe thunderstorm. Sensitivity experiments are conducted to study the impact of using different grid resolution (9km and 3km) with terrain resolution 5 mm (-.10 krn) and I mm (—.2 km) respectively and the same microphysics and cumulus parameterization schemes on simulation of the system. The results demonstrate that the model simulates better structure and intensity of the thunderstorm at higher resolution domain. The model forecasts are - compared with observational data from different sources such as Doppler Weather Radar (I)WR), Automatic Weather Station (AWS) and Satellite data. Although the present study is - based on only one severe thunderstorm, it could be useful for planning real-time prediction using WRF modeling system. More comprehensive case studies including different physical parameterization sensitivity experiments can be explored for future research work.