CHENNAI: Tamil Nadu’s rainfall position has improved sharply in the opening weeks of the northeast monsoon, helping the state recover from widespread deficits recorded at the end of the southwest monsoon. Between Oct 1 and 27, the state received 217mm of rain against the normal 144mm, registering a 51% surplus.Tamil Nadu had ended the southwest monsoon with a 16% deficit. “In a striking shift in Tamil Nadu’s rainfall position, 18 of the 23 districts that were rainfall-deficient at the close of the southwest monsoon have moved out of the deficit category since October. As of Oct 27, only five districts continued to record deficient cumulative rainfall, while several others had moved into the normal or excess categories,” commissioner of revenue administration and disaster management B Chandra Mohan said. So far in Oct, no district has recorded deficient rainfall.Several districts that began October with significant shortfalls have since moved closer to, or above, their normal cumulative rainfall levels. Coimbatore received 313mm against the normal 137mm during the 27-day period, recording a 128% surplus. Tirunelveli received 258mm against 123mm, a surplus of 110%, while Dindigul recorded 328mm against the normal 166mm, a 97% surplus. Western and interior districts, including Erode, Karur, Namakkal and Tiruppur, also recorded significant gains. Chennai received 289mm during the period, 33% above normal.For the June 1-Oct 27 period, Tirunelveli remained in the large excess category, while Tenkasi, Dindigul, Coimbatore and Perambalur recorded excess rainfall. However, Chengalpet, Thanjavur, Kancheepuram, Vellore and Tuticorin continued to record deficient cumulative rainfall as of Oct 27. Their departures from normal stood at 38%, 30%, 24%, 22% and 20%, respectively.Tuticorin’s deficit has narrowed considerably from the 65% recorded at the end of the southwest monsoon. However, rainfall in October was only close to normal in the district, and the earlier shortfall continues to weigh on its cumulative position, Chandra Mohan said.Officials cautioned that rainfall distribution within a district can vary significantly, particularly across reservoir catchments. A narrowing rainfall deficit, therefore, does not by itself indicate a corresponding improvement in groundwater levels or reservoir storage. “With November and December still ahead, the season remains in progress. Continued monitoring will be important, particularly in districts where deficits persist and in catchments where rainfall distribution remains uneven,” Chandra Mohan said.
