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1. A severe thunderstorm has occurred over Purnea, Araria and Kishanganj districts of Bihar at about 2305 hrs IST of 13th April 2010. Atmospheric conditions in association with the thunderstorm have been analyzed using satellite imageries, synoptic charts analysis, Weather Research and Forecasting (WRF) model, Global Forecast System (GFS) model products of India Meteorological Department (IMD) and European Centre for Medium Range Weather Forecasting (ECMWF) model products and discussed in this paper. It is inferred from this case study that continuous monitoring of satellite imageries and Radar products if available, during favourable atmospheric conditions could provide significant indication of thunderstorm activity to the operational forecasters.

Thunderstorms are atmosphere’s most familiar dramatic events. Destructive off springs of thunderstorms are the hailstorms, lightning, high winds, heavy rains and most violent of all are the tornadoes. In India, theses thunderstorms reach severity when continental air meets warm moist air from Ocean. Essential conditions for the formation of a severe thunderstorm are (i) Conditional instability (ii) Availability of moist air at lower levels (iii) Insolation and orography for initial lifting of moist air at higher levels.(iv) Presence of high lapse rate of temperature, due to dry westerly at upper levels and moist southerly/southwesterly air at lower levels.(v) Presence of trough or cyclonic circulation in lower levels over the region. In addition, strong vertical wind shear is found to be one of the important factors for the occurrence of severe thunderstorm as the release of latent energy in an environment of …