Amaravati, Nov 21 : The Met department has forecast thunderstorms with lightning in parts of south coastal Andhra Pradesh and Rayalaseema on Wednesday, following the development of a cyclonic circulation over equatorial Indian Ocean and adjoining southeast Bay of Bengal sea, which is expected to bring rain. "Under the influence of the cyclonic circulation over Equatorial Indian Ocean and the adjoining Southeast Bay of Bengal, a low pressure area has formed over central parts of south Bay of Bengal," said a Met official. Influenced by the low pressure, an associated cyclonic circulation is extending up to the mid-tropospheric level. "It is likely to concentrate into a depression over Southwest Bay of Bengal during the next 48 hours and intensify further during the subsequent 48 hours," said the official. According to the Met department, the depression is likely to move west and north westwards towards Sri Lanka and south Tamil Nadu to reach the Tamil Nadu and Puducherry coast on Wednesday. On Friday, all the monitoring stations in the southern state recorded maximum temperatures between 30.7 degrees Celsius and 34.7 degrees Celsius. Kurnool recorded the maximum temperature of 34.7 degrees Celsius while Anantapur recorded the least at 14.7 degrees Celsius. /IANS