"All out preparedness is underway at the coastal areas," disaster management minister Mahmud Ali told a news briefing as the Met office issued a bulletin in the evening saying Mahasen at the southeastern bay had moved slightly northwestwards.
The bulletin said the cyclone was likely to intensify further and move in a northerly direction though the earlier issued storm intensity of 4 on a scale of 10 remained unchanged.
According to the bulletin the cyclone now lies over West Central Bay and adjoining east Central Bay and was centred at 6 pm today about 1080 kms southwest of Chittagong Port, 1015 kms Southwest of Cox's Bazar Port and 970 kms South Southwest of Mongla Port.
"We, however, don't expect the cyclone to hit our coastline before tomorrow night or Thursday morning," Met office director Shah Alam told PTI.
More From This Section
He also said the meteorologists were not sure if the Mahasen would definitely hit the Bangladesh coast or shift course but added that the scenario could be clearer by tomorrow evening.
But 13 vulnerable districts along the southern coastline witnessed cloudy weather with rainfall throughout the day while officials said they were preparing for a massive evacuation, stockpiling dry food and mobilising medical and rescue teams.
The last such cyclone 'Aila' devastated Bangladesh coastline in 2009 killing 190 people but a deadlier tidal surge Sidr ravaged the coastlines in 2007 claiming 3363 lives.
Hundreds of small fishing boats and trawlers in the north Bay rushed to the shore for shelters responding to the warnings for the first such storm in the season to approach Bangladesh coast.