Fairly widespread to isolate heavy rain may return initially to coastal areas of Tamil Nadu before spreading to other parts of the adjoining parts of the South Peninsula, as easterly winds begin to straighten out yet again after a similar act earlier last week dumped heavy rainfall over Thoothukudi, Tenkasi and Kanniyakumari districts.
Need to be watched
Weather charts do not indicate the formation of a cyclonic circulation in the neighbourhood, one of which had engineered the precipitous heavy torrents over South Tamil Nadu, amounting to as high as 95 cm during 24 hours at Kayalpattinam. But the region would need to be watched carefully, given the predicted pick-up in easterlies in the Gulf of Mannar/Palk Strait.
It is pertinent to point out here that the India Meteorological Department (IMD)has signalled the formation of a circulation farther to the South of Sri Lanka, with a strong of easterlies hitting Sri Lanka as well the South-East coast of Tamil Nadu to the North-West. It may intensify, but drive away to the open Indian Ocean out of harm’s way for Sri Lanka/South India by December-end.
Isolated heavy rain
An extended outlook by the IMD week from December 28 to January 3, 2024, said light/moderate scattered to fairly widespread rain is likely over extreme South Peninsular India and the Andaman & Nicobar and Lakshadweep Islands. Isolated heavy rain is likely for one or two days over the Andaman & Nicobar Islands and Tamil Nadu during the week.
Overall, normal to above normal rainfall activity is likely over extreme South Peninsular India during the week, while it would be mainly dry over the rest of the areas of the country except the North-Eastern States, the Andaman & Nicobar Islands, the hills of West Bengal and Sikkim and in North-West India, where rainfall is likely to be normal to be below normal.
Global model forecast
A few global models suggest heavy rain along the coast of Tamil Nadu and adjoining interior from December to January 10 and above normal rainfall over parts of Peninsular India (Goa, South Maharashtra, Telangana and South Andhra Pradesh.) Enhanced rain is also likely over Madhya Pradesh and adjoining northern parts of Maharashtra. The rest of the country may also receive passing showers, and the rain intensity will reduce into the rest of January, realising the highest amounts still along the Tamil Nadu coast.