CHENNAI: The well-marked low-pressure area over the Bay of Bengal is likely to concentrate into a depression over the southwest part of the bay by Wednesday, said the Regional Meteorological Centre (RMC), Chennai, forecasting light to moderate rainfall at a few places in Tamil Nadu till January 10.
The low-pressure area was formed over the southeast Bay of Bengal on Monday due to the influence of an upper air cyclonic circulation over the Equatorial Indian Ocean and adjoining central parts of the south Bay of Bengal.
“On Tuesday, it strengthened into a well-marked low-pressure area over the same region. In the subsequent 24 hours, the system is likely to move northwestward and concentrate into a depression over the Southwest Bay of Bengal," it said.
A cyclonic circulation lies over the Comorian area and its neighbourhood, and another cyclonic circulation lies over the east central Arabian Sea and adjoining Lakshadweep area, the weather office added.
According to its bulletin, light to moderate rain is likely at isolated places over coastal Tamil Nadu and Puducherry, and dry weather is expected to prevail over the interior parts of the State on January 7.
Heavy to very heavy rain is likely at isolated places over Mayiladuthurai, Nagapattinam, Thanjavur, Tiruvarur, and Pudukkottai, while heavy rain is likely at isolated places over Chengalpattu, Ramanathapuram, Sivaganga, Tiruchy, Ariyalur, Cuddalore, and Villupuram districts, and Puducherry on January 9.
Similarly, heavy to very heavy rain is likely to occur at isolated places over Chengalpattu, Cuddalore, and Villupuram districts, and Puducherry, and heavy rain at isolated places over Chennai, Tiruvallur, Kancheepuram, Ranipet, Mayiladuthurai, Nagapattinam, Thanjavur, Tiruvarur, Ariyalur, Perambalur, Kallakurichi, and Tiruvannamalai districts, and Karaikal area on January 10.
Meanwhile, explaining the prolonged northeast monsoon season, RMC section in-charge B Geetha said it normally ends by December 30, though it has extended into January in about 30-35 years in the last 100-120 years.