Meeting the press on Monday, S Balachander, director of the Area Cyclone Warning Centre at the Regional Meteorological Centre said that the low-pressure area formed in the Bay of Bengal is expected to move northwards in the next two days, following which rainfall would gradually decrease across Tamil Nadu. Northern coastal districts including Chennai, Kancheepuram, Thiruvallur, Cuddalore, Villupuram might receive isolated heavy showers, he added.