Thunderstorm climatology over northeast and adjoining east India

Abstract

In this study an attempt has been made to develop climatology of thunderstorm, hail and squall over the northeast and adjoining east India region based on data of 26 India Meteorological Department (IMD) observatories for the months of April and May during 1981-2008. The data of 8 Indian Air Force (IAF) observatories in these regions which are available for the period of 1991-2008 have also been considered. The interannual & intraseasonal variation, climate change aspects and diurnal variation of occurrence of thunderstorms have been analysed and discussed.

The frequency and time of occurrence of thunderstorm, hail and squall days over the region show large spatial variation. The orographically dominant regions as well as the coastal areas are more prone for such activity. There is increasing trend in number of thunderstorm days over some parts of south coastal Orissa and coastal West Bengal and decreasing trend over some parts of north coastal Orissa, Manipur, Mizoram and Tripura in recent years.