A deep depression hovering over the Bay of Bengal may intensify into a cyclonic storm by Tuesday morning and is likely to cross the north Tamil Nadu coast and adjoining south Andhra Pradesh by October 31 midnight, the Met office said.

The deep depression lay over the southwest Bay of Bengal, about 550 km south-southeast of Chennai and 200 km east-northeast of Trincomalee. If it intensifies into a cyclonic storm, it would be the season’s first cyclone to strike the State.