CHENNAI: With the northeast monsoon set to begin next month (October), private weather forecasters have started issuing predictions about the intensity of rainfall this year.
According to Delta Weatherman Hemachander, this year’s northeast monsoon is expected to be influenced by La Niña and negative IOD events, along with favourable oceanic oscillations such as the Madden-Julian Oscillation and equatorial Rossby waves over the eastern Indian Ocean and South China Sea.
These factors, coupled with prolonged tropical convergence closer to the equator near Tamil Nadu and Sri Lanka, are likely to trigger frequent weather systems moving towards Tamil Nadu, said a Daily Thanthi report.
As a result, Tamil Nadu is expected to record 20% to 35% above-normal rainfall during the northeast monsoon season, he said.
The forecast also indicates that successive low-pressure systems, depressions, and cyclones will bring rains this year. In particular, back-to-back cyclones may form during late November and early December, with their landfall signs pointing towards the Delta region, north Tamil Nadu, and south Andhra coastal areas.
This year’s northeast monsoon is also predicted to extend into January, with chances of above-normal rainfall even during the winter months of January and February.
Meanwhile, private forecasts highlight an increasing trend of short-duration, heavy rainfall events in recent times. Accordingly, districts including Chennai, Tiruvallur, Kancheepuram, Chengalpattu, Villupuram, Cuddalore, Mayiladuthurai, Nagapattinam, Tiruvarur, Thanjavur, Ramanathapuram, Thoothukudi, as well as Puducherry and Karaikal, may witness intense downpours this season.