A man tries to hold on to an umbrella on Chennai’s Marina beach on Tuesday. (Reuters)

New Delhi, Oct 30: A Bay of Bengal cyclone with top wind speeds of 100-kmph, but a dwarf compared to the superstorm Sandy that ravaged northeastern US today, is likely to strike Tamil Nadu Wednesday evening.

The cyclone, named Nilam, will bring fierce winds, intense rain, and inundate low-lying coastal areas through storm surge waves of up to one-metre above normal tide levels during its landfall, meteorologists said today.

Forecasts of the cyclone's future trajectory suggest it will hit the coast somewhere between Cuddalore in Tamil Nadu and Nellore in Andhra Pradesh, the India Meteorological Department said.

Independent simulations by Indian and foreign weather agencies have assigned the highest probability of landfall over Chennai, Kanchipuram, or Thiruvallur districts in Tamil Nadu.

'We expect damage to thatched hutments, trees, and crops, and power and telephone line disruptions,' Mrutyunjaya Mahapatra, the head of the cyclone warning division at the India Meteorological Department said.

The IMD has said squally winds with speeds up to 65-kmph could prevail along northern Tamil Nadu and adjoining southern Andhra Pradesh over the next 12 hours and wind speeds will increase as the cyclone looms closer to the coast.

'We're asking fisherfolk already in the sea to come back and those on land not to sail into the sea,' Mahapatra said. The IMD has predicted 'very rough seas' off northern Tamil Nadu, Puducherry, and southern Andhra Pradesh over the next 48 hours.

Scientists from the IMD will meet Chennai airport officials tomorrow morning to take a decision on whether to shut down the Chennai airport.

'The decision will depend on the tailwinds and crosswinds that we expect tomorrow evening along the approach path and the runway,' Ramachandran Suresh, director of aviation meteorological office in Chennai told The Telegraph .

Commercial aircraft, Suresh said, have limits on the speeds of tailwinds and crosswinds in which they can operate.

An atmospheric depression over the southern Bay of Bengal intensified into a deep depression on Monday and evolved today into a cyclonic storm that lay centred this evening about 450-km south-southeast of Chennai and 130-km north-northeast of Trincomalee in Sri Lanka. 'It's moving north-northwest direction and we expect landfall on Wednesday evening,' a senior IMD scientist said.

Scientists say Nilam is a dwarf in relation to Sandy, the severe north Atlantic cyclone that made landfall near Atlantic city, New Jersey, at about 530 AM IST today with hurricane wind speeds extending up to 250-km from the centre of the storm.

The most severe winds from Nilam are expected to stretch only about 120-km to 130-km from the eye of the storm, a senior IMD scientist said. 'Many factors contribute to the size of a cyclone, one of them is the water basin and cyclones in the Atlantic and Pacific are typically bigger than those in the Bay of Bengal or the Arabian Sea,' the scientist said.

The IMD said it has alerted state authorities as well as issued cyclone bulletins for airports and will continue issuing alerts every three hours as the cyclone approaches.

The names of northern Indian ocean cyclones are picked from a roster of names suggested by eight northern Indian Ocean rim countries -- Nilam, picked from a pre-defined sequence, is among eight names suggested by Pakistan.