Coimbatore: Twenty-one districts, including Coimbatore and many other western districts in Tamil Nadu are expected to get normal rains in the ensuing southwest monsoon.
“Eleven other districts, including coastal districts like Nagapattinam, Ramanathapuram and Tiruvarur are likely to get deficit rainfall. The SW monsoon began in Kerala on Tuesday and it will set in gradually in a day or two in Tamil Nadu. Sixty-five percent of Tamil Nadu will receive normal rainfall in this monsoon,” said S. Panneerselvam, professor and head of the Agra Climate Research Centre at Tamil Nadu Agricultural University (TNAU).
Normal rainfall is expected in Coimbatore, Salem, Namakkal, Dharmapuri, Krishnagiri, Nilgiris, Chennai, Cuddalore, Dindigul, Erode, Kancheepuram, Kanyakumari, Madurai, Perambalur, Pudukottai, Sivagangai, Theni, Tiruvallur, Tiruvannamalai, Villupuram and Vellore districts during the ensuing SW monsoon.
While the long time average normal rainfall in Coimbatore during the SW monsoon is 189.8 mm, the expected rainfall is 167mm, which is a division of minus 14 per cent. However, a deviation of plus or minus 19 percent from long period average rainfall is considered to be normal.
The last SW monsoon left Coimbatore disappointed with a mere 68 mm of rainfall as against the expected 200 mm. In 2015, the district registered 146 mm of rains and a copious 218 mm of rains in the year before.
“As far as summer rains are concerned, Coimbatore received 122 mm in the months of March, April and May as against the normal 130 mm. The temperature may dip gradually by the end of the summer on Wednesday. Also, the wind speed which hovers around 7kms now would increase to up to 20 km in the coming days,” said S. Panner Selvam.
It may be challenging for the water management front four districts including Nagapattinam, Ramanathapuram, Tuticorin, Tirunelveli, Tirupur, Karur, Virudunagar, Trichy, Thanjavur, Ariyalur and Tiruvarur as they are expected to receive only below normal rainfall (minus 20 per cent to minus 59 per cent in the SW monsoon.
Nilgiris is likely to get the highest rainfall of 776 mm and it will be followed by Kancheepuram at 490.8 mm. Chennai will also get a normal rainfall of 439.1 mm, but with a deviation of minus 11 per cent. Tuticorin would receive the lowest rainfall of 57mm with a deviation of minus 31 per cent.
