As a deep depression has been formed over the Bay, tidal surges ranging from three to five feet height may inundate the low-lying areas of the costal districts, the Met Office in a special bulletin on Friday said.

The Met Office also advised maritime ports to hoist local cautionary signal number 4 and warned that low-lying coastal areas could be inundated by tidal surges.

Due to the influence of the depression country’s different parts are experiencing light to moderate rains. The sky remains overcast with dark clouds since Thursday evening.  

Besides, heavy to very heavy rains will also continue today (Saturday).  

According to the Met Office, after the rain the monsoon will disappear and the winter will set in at the middle of the next month.

Launch and other water vessel services on different river routes across the country have been suspended due to inclement weather.

In a special bulletin on Friday morning it said a deep depression has formed in the Bay of Bengal. It was located in the northwest Bay and adjoining area and moved northeastwards over the same area.

At 6am, it was centred about 445km west-southwest of Chittagong Port, 445km west-southwest of Cox's Bazar Port,  240km southwest of Mongla Port and 280km southwest of Payra Port.

It is likely to move in a northeasterly direction, the weather office said.

The maximum sustained wind speed within 48km of the deep depression centre is about 50kph rising to 60kph in gusts. The sea will remain rough near the deep depression centre, the bulletin said.

Parts of Bangladesh, including capital Dhaka, have been experiencing rain since yesterday.

Meanwhile, the Met Office warned that under the deep depression’s influence, low-lying coastal areas could be inundated by tidal surge of three to five feet height above the normal astronomical tide.

Areas that could see tidal surge are Satkhira, Khulna, Bagerhat, Jhalakathi, Pirojpur, Barguna, Patuakhali, Bhola, Barisal, Lakshmipur, Chandpur, Noakhali, Feni, Chittagong and their offshore islands and chars.

All fishing boats and trawlers over the North Bay and deep sea have been advised to remain in shelter until further notice, the Met Office said.

In another forecast the Met office said due to the well-marked low over the Northwest Bay and adjoining West-central Bay heavy (44-88mm) to very heavy (89 mm) rainfall is likely to occur at places over Rajshahi, Rangpur, Dhaka, Khulna, Barishal, Chattogram, Mymensingh and Sylhet divisions during the next 48 hours commencing today  (Saturday)

Even light to moderate rain/thundershowers accompanied by temporary gusty wind is likely to occur at most places over Dhaka, Mymensingh, Rajshahi, Rangpur, Khulna, Barishal, Chattrogram and Sylhet divisions with heavy to very heavy falls at places over the country, said a Met Office press release.

Yesterdays well-marked low over northwest Bay and adjoining west central Bay moved northwestwards and intensified subsequently into a depression afterwards deep depression and then depression over North-west Bay and adjoining area; moved northeastwards over the same area (lat 21.0oN and long 88.0oE) and was centered at 9am on Friday.