Cyclone Gaja intensified into a severe cyclonic storm on Thursday and is expected to cross the south Tamil Nadu coast by late evening or night, with the government machinery put on high alert.

The storm which lay over the Southwest Bay about 140 km east of Nagapattinam and Karaikal in Puducherry was very likely to cross the coast between Cuddalore and Pamban around Nagapattinam by evening or night after weakening into a cyclone, Deputy Director General of Meteorology S Balachandran said.