A deep depression lying 500 km south east of Chennai has intensified into a cyclonic storm and is expected to cross the coast between Nagapattinam in Tamil Nadu and Nellore in Andhra Pradesh tomorrow, bringing in torrential rains in the region.

The system, named Nilam, as suggested by Pakistan under the cyclone naming procedure, would move northwestwards and cross the coast between Nagapattinam and Nellore by tomorrow afternoon/evening.

Under the influence of the storm, rainfall at most places, with isolated heavy to very heavy rainfall, would occur over coastal Tamil Nadu and Puducherry during next 12 hours, an bulletin issued by Area Cyclone Warning Centre here at 1 pm said.

It forecast heavy to very heavy rainfall and isolated extremely heavy rainfall (25 cm or more) in the region during the subsequent 36 hours. "Squally winds speed reaching 45-55 kmph gusting to 65 kmph would prevail along and off north Tamil Nadu, Puducherry and adjoining south Andhra Pradesh coasts during next 12 hours.

The wind speed would gradually increase thereafter as the system comes closer to coast," it said.