Upper-air radiosonde observations, taken during “Cloud Aerosol Interaction and Precipitation Enhancement EXperiment” (CAIPEEX) at Mahabubnagar (16.73°N, 77.98°E) under Integrated Ground Observation Campaign (IGOC) during the second half of southwest monsoon of 2011 have been analysed. Various weather data taken from India Meteorological Department as well as NCEP/NCAR reanalyzed upper-air wind data for the months August and September of 2011 have also been used in the study. Intra-seasonal variation of monsoon, during the period of experiment, has been studied.

The Bengal Basin evolved as a rift-controlled extensional basin along the NNE–SSW trending Basin Margin Fault coevally with the 85 East Ridge in the Bay of Bengal during the short-lived hotspot activity south of Bhubaneswar. The basin opening post-dated the Kereguelen Plume magmatism (at ~116 Ma), but predated the phase of continental collision that triggered the rise of the Himalaya in the north. Supply of sediments in the initial stages of basin opening was from the west, mainly through the denudation and erosion of the uplifted Precambrian Shield.