Effects of off-shore vortices on rainfall along the west coast of India

Abstract

Information and dissipation of small scale circulations and vortices take place incessantly along the west coast of India, during the monsoon season. Some of these vortices are found to develop into significant shape and size and make noteworthy contributions towards rainfall along the west coast. The occurrence of rainfall relatively heavier over the coastal stations away from the ghats than over sections close to the ghats is not an uncommon feature. This peculiar distribution of rainfall is found to occur under the influence of off shore vortices,

These vortices are of the order of 30 to 100 miles in horizontal extent, They generally move northwards parallel to the ghats,' The variations, of surface winds experienced at the stations provided with autographic records reveal that there are a few significant, points connected with all well-developed vortices, and that the rain fall associated with a vortex is usually heaviest between the 'core' region and the 'confluent' region of the vortex.