The well-marked low over Southeast Bay and adjoining area moved north-northwestwards, intensified into a depression over Southeast Bay and adjoining Southwest Bay.
It now lies at 6am on Sunday about 1,950km Southwest of Chittagong, 1,900km Southwest of Cox's Bazar, 1,820km Southwest of Mongla and 1,825km Southwest of Payra, said a Met Office bulletin.
It is likely to move north-northwestwards and further intensify into a cyclonic storm.
Maximum sustained wind speed within 44km of the Depression centre is about 40kph rising to 50kph in gusts or squalls.
Sea will remain moderate near the depression centre.
Maritime ports of Chittagong, Cox's Bazar, Mongla and Payra have been advised to hoist distant cautionary signal No. 1.
All fishing boats and trawlers over North Bay have been advised not to venture into the deep sea till further notice.
