Impact of Winds of Various Layers upon Thunderstorms and Rainfall over Vidarbha

Abstract

The meteorological data of Nagpur for forty years (1965-2004) are considered to conduct this study. It has been observed from this study that the frequency of occurrence of thunderstorms is the highest in the month of July and lowest in January during the year. There is positive and significant correlation between the number of thunderstorms occurred and the amount of rainfall. It is observed that there is decreasing trend in the days of occurrence of thunderstorms and rainfall. It is also found that winds are changing in southerly direction at the surface, 850 hPa and 200 hPa levels. It is pointed out that the maximum chances of formation of squalls is observed in the transition period of onset of southwest monsoon and its withdrawal. The wind shear between 850 hPa level & the surface and the differences in wind directions between 200 hPa & 850 hPa levels are found to be more related to the formation of thunderstorms. Winter season is observed to be most safe period for aviation purposes due to lesser frequency of occurrences of thunderstorms over Nagpur. This study has relevance to the forecasters, aviation sector and farmers.