The authorities in Bangladesh have ordered the evacuation of some 100,000 people from coastal areas as Cyclone Bulbul is set to hit the country.
The storm – which is due to make landfall on Saturday evening local time – is expected to unleash surges as high as 7ft (two metres).
A dozen low-lying coastal districts are said to be in its path.
A number of sea ports, including Mongla and Chittagong, have been placed on high alert.
Bulbul is expected to make landfall near the Sundarbans, the world’s largest mangrove forest and home to the endangered Bengal tigers.
It is set to reach wind speeds of up to 120km/h (75mph), with gusts of 150km/h, and create tidal surges in the sea and rivers when it hits the coastal regions, says the Bangladesh Meteorological Department.
Thousands of volunteers will go door to door to alert people about the storm.
Cyclones have often hit Bangladesh in the past, killing thousands of people, but the country has successfully reduced the number of casualties in recent years by being better prepared.
Early cyclone warning systems have improved, giving authorities more time to evacuate people. Cyclone shelters have been built over recent years.
Local authorities have ordered school buildings and mosques to be used as shelters in addition to dedicated shelters, the Associated Press news agency reports.