Northeast monsoon has been generally dormant over South Peninsula for the last few days. All pockets witnessed far and few showers. Rains were deficient for the state of Tamil Nadu at a stretch for the last 4 days. Last two days, monsoon rains were missing in toto resulting rise in the seasonal deficiency. Between 01st October and 15December 2023, the state has marginal rainfall deficiency of 6%. Upcoming rains are likely to reduce this margin and expected to break even by early next week.
There is a broad cyclonic circulation over Sri Lanka, Gulf of Mannar and Comorin region. This feature is likely to become more marked and extend northward to reach parts of Tamil Nadu, more so, the interior parts. Cyclonic circulation will move westward, slowly across Maldives and further on to the southeast equatorial Indian Ocean. Spike in the northeast monsoon is likely over the next four days covering Sri Lanka, Tamil Nadu, Gulf of Mannar, Comorin, Maldives and Lakshadweep Islands.
Southern and coastal parts of Tamil Nadu will have heavy to very heavy rains on 16th and 17th December. Locations at risk will include Tirunelveli, Thoothukudi, Sivaganga, Tondi, Tuticorin, Pamban, Nagapattinam and Cuddalore. The interior stations like Dindigul, Trichy, Tiruvarur, Thanjavur, Madurai, Karur, Erode and Coimbatore will also have similar weather conditions over these 2 days. Later, the rains will shift towards north coastal Tamil Nadu and the spread will decrease, as well. On 18th and 19th December, the stations to be watched out for inclement weather conditions will include the capital city Chennai, along with Kancheepuram, Tambaram, Chengalpattu, Karaikal and Puducherry.
The circulation will reach a safe distance from the state of Tamil Nadu and Kerala on 20thDec and later. Weather conditions will improve significantly on 20th December itself and further become better on the following days.