Ports of Chittagong, Cox’s Bazar, Mongla and Payra have been asked to hoist Local Cautionary Signal no-3.
Rain is expected over areas in Khulna, Barisal and Chittagong divisions on Friday and Saturday.
Medium showers with gusty winds and thunder storm are also expected in parts Dhaka, Mymensingh and Sylhet divisions.
The depression over west central bay is likely to intensify further and move in a north-westerly direction, said a special weather bulletin on Friday.
“The low was causing deep convections over the North Bay. Stormy weather is expected to sweep over coastal regions and port areas due to its effect,” said meteorologist Abul Kalam Mollik.
Fishing boats and trawlers should not venture out into the deep sea, and stay close to the coast until further notice, said the Met Office bulletin.