
The northeast monsoon has since long withdrawn from the southern parts of India. However, the equatorial circulations and perturbations have been maintaining flow affecting the South Andaman Sea, South Bay of Bengal, Sri Lanka, Comorin and Maldives. The northward extension of these disturbances does reach Tamil Nadu and Kerala to trigger a few spells of winter rains. These two pockets had decent showers between the 13th and 15th of January 2025. Very light rains were recorded in the past 24 hours also. These are likely to have a pause for 48 hours and pick up again on the weekend.
A Cyclonic Circulation, presently over southern parts of the central Bay of Bengal will reach Sri Lanka on 18th January and move further to the Comorin region, the next day. The northward extension of the trough from the circulation will trigger a fresh bout of rains over Tamil Nadu and Kerala on these two days.
The rainfall is likely to be heavy along coastal parts of Tamil Nadu on 18th Jan. The pulse will travel inland and moderate to heavy rainfall is expected over the interiors of Tamil Nadu and adjoining Kerala on 19th Jan. The spread and intensity could be more on the second day. The weather system will move further westward over the Southeast Arabian Sea and the neighbourhood on 20th Jan. While moving further away, the system may intensify into a low-pressure area over the South & Southeast Arabian Sea. However, the Indian coastline will be at a safe distance and unlikely to be impacted.