As water is a bad conduct of heat so there is alway an uneven heating pattern noticed in case of land mass and mass and water bodies. In summer the landmass of northern Indian is much hotter that the surrounding water in the oceans most of the times. The air above the land becomes hot up and rise and the wind from the ocean carrying water bodies these winds called winter monsoon bring scanty rainfall to coastal tamil Nadu  as they take moisture while blowing over Bay of Bengal.

Differant types of storms are caused by strond by strong air cirrents and are accompanied by lightning heavy rains and high speed winds lightning there the storms may occur on land or over the seas.                             Thunderstorm.               Thunderstorm occur in hot humid tropical areas such as india most frequently. the air over the land gets heated becomes light  and rises. In doing so the water vapour condenses fast form tiny droplets of Water which freeze forming ice particles during the condensation of water  vapour and freezing of droplets. A large a large anount of heat is given out which further pushes the air up at a  higher speed.