CHENNAI: Close on the heels of the recent weather system that brought significant rainfall to Chennai and the delta districts, along with extremely heavy downpours in the southern districts of Tamil Nadu, the Regional Meteorological Centre (RMC) on Sunday announced that a new low-pressure area is likely to form over the southeast Bay of Bengal on Monday. The system is expected to bring heavy to very heavy rainfall to the delta districts on Tuesday, it stated.
The low-pressure area is to be formed under the influence of an upper-air cyclonic circulation, which was located over the South Andaman Sea and adjoining areas on Saturday and subsequently moved to the South Andaman Sea and the adjoining Bay of Bengal by Sunday. It is likely to become more marked and move west-northwestwards towards the Tamil Nadu coast in the next two days.
As per the RMC’s forecast, an orange alert (heavy to very heavy rains) has been issued to Cuddalore, Mayiladuthurai, Nagapattinam and Tiruvarur districts and Karaikal area for Tuesday. Heavy rain is likely to occur at isolated places over Chengalpattu, Villupuram, Kallakurichi, Ariyalur, Perambalur, Tiruchy, Thanjavur and Pudukkottai districts and Puducherry.
On Wednesday, heavy to very heavy rains are likely in isolated places over Cuddalore and Villupuram districts and Puducherry. Heavy rain is likely to occur at isolated places over Tiruvallur, Chennai, Chengalpattu, Kancheepuram, Ranipet, Tiruvannamalai, Kallakurichi, Mayiladuthurai, Nagapattinam and Tiruvarur districts and Karaikal area, the forecast stated.
Tirunelveli dist records 13 cm rainfall in 24 hrs
Weather blogger K Srikanth said that there is an increasing consensus among the weather models about the low-pressure area becoming well-marked and its potential slow movement due to presence of a ridge over peninsular India.
Any stall or slow movement could turn the rainfall event into widespread heavy rainfall over the northern Tamil Nadu coast. The potential for westerly/easterly interaction near south coastal AP or north coastal TN is increasing and it could bring an extreme rainfall event between Marakkanam and Sriharikota.
The stretch between Pondicherry and Nellore may see heavy to very heavy rains during this period, he said. After intensification, the well-marked low-pressure region will approach the north TN coast and then move along southern AP coast, potentially bringing moderate to heavy rainfall on December 18 and 19, lasting for 24 to 36 hours, subject to real-time tracking.
In the 24 hours ending at 8.30 am on Sunday, Papanasam in Tirunelveli district recorded the highest rainfall at 13cm.