The depression lay centred over the coastal areas of West Bengal and Khulna at 12 pm Friday and is likely to cross the coasts by 6 pm, according to the Met Office's special weather bulletin.
With winds packing speeds of 40-50 KPH, the sea is expected to remain rough near the depression centre.
Maritime ports of Chattogram, Cox's Bazar, Mongla and Payra have been advised to keep hoisted the local cautionary signal No. 3.
Meanwhile, parts of Dhaka, Chattogram, Barishal, Khulna and Sylhet, among others, are likely to witness 'heavy to very heavy' rainfall due to the depression.
The low-lying areas of the coastal districts may experience flooding from wind-driven waves that could be 3 to 5 metres higher than usual, according to the Met Office.
All fishing boats and trawlers have been advised to remain in shelter until further notice.