The Met office has asked four maritime ports to issue cautionary signal No. three due to a depression that developed over west central bay now lies over northwest bay and adjoining west central bay.
The Bangladesh Meteorological Department released the information in a special weather bulletin on Thursday.
The depression, which moved north-northeastwards, is likely to intensify further and move in a northeasterly direction, reports UNB.
It was centred on Wednesday midnight about 985 kms southwest of Chittagong port, 965 kms southwest of Cox's Bazar port, 795 kms southwest of Mongla port and 830 kms southwest of Payra port.
Maximum sustained wind speed within 44 kms of the depression centre is about 40 kph rising to 50 kph in gusts/squalls.
Sea will remain moderate near the depression centre.
All fishing boats and trawlers over North Bay and deep sea have been advised to proceed with caution. They are also advised not to venture into the deep sea.