Danger signal 7 was advised for the maritime ports of Mongla and Payra and 6 for Chattogram.
Cox’s Bazar was advised to keep hoisted local warning signal number 4.
Costal districts of Chattogram, Noakhali, Laxmipur, Feni, Chandpur and their offshore islands and shoals will come under danger signal 6, the Met Office said in a special weather bulletin in the evening.
‘Bulbul’ has intensified further and now lies over Northwest Bay and adjoining west-central Bay.
It was about 620km southwest of Chattogram port, 585km southwest of Cox’s Bazar port, 495km southwest of Mongla port and 490km southwest of Payra port at 6pm.
“It is likely to intensify further,” the Met Office said, adding that it may hit Khulna coast near Sundarbans by Saturday evening.
Under its peripheral influence, gusty or squally windy may affect the maritime ports, North Bay and coastal areas from Sunday morning.
The maximum sustained wind speed within 74km of ‘Bulbul’s centre is about 120kph rising to 140kph.
Under the influence of the very severe cyclone storm and the moon phase, low-lying areas of coastal districts of Chattogram, Noakhali, Laxmipur, Feni, Chandpur, Borguna, Bhola, Patuakhali, Barishal, Pirojpur, Jhalokathi, Bagherhat, Khulna, and Satkhira are likely to be inundated by storm surge of 5-7 feet height above normal astronomical tide.
All fishing boats and trawlers over North Bay have been advised to remain in shelter until further notice.