A depression about 650 km east-southeast of Chennai and 680 km northeast of Nagapattinam is expected to intensify into a deep depression and cross the coast of north Tamil Nadu between Nagapattinam and Chennai by Friday night or Saturday morning, bringing torrential rains to the region.
This rain spell is crucial for the State, as it has so far received only 161 mm of rain, which is 39 per cent lower than the average for the season.
Officials of the meteorological department said several districts in north coastal Tamil Nadu, including Cuddalore, Chennai and Tiruvallur, were expected to receive rain. Some places may have a downpour of up to 25 cm from Friday.
Y.E.A. Raj, deputy director general of meteorology, Regional Meteorological Centre, Chennai, said places between Nagapattinam and Nellore would receive rainfall. “But the amount of rain the State will get is unclear as we are still tracking the movement of the depression,” he said.
The department issued a bulletin on Wednesday warning that minor damage could occur in unstable structures in north Tamil Nadu, Puducherry and south coastal Andhra Pradesh.
As the sea would be very rough along and off the north Tamil Nadu and Puducherry coasts, fishermen have been warned not to venture into the sea from Friday.
Squally winds with speeds up to 75 kmph off north Tamil Nadu and Puducherry will also begin from Friday.
Meanwhile, in Nagapattinam on Wednesday, signal one was hoisted at the port office signalling a distant warning to all those at sea.