Southwest Monsoon forecast: Normal rainfall expected in 65 percent of Tamil Nadu

Coimbatore: Sixty-five percent of Tamil Nadu would receive normal rainfall during the Southwest Monsoon, Tamil Nadu Agricultural University said on Tuesday.

Representational image. Reuters

Tamil Nadu is a rain shadow area to Southwest Monsoon and nearly 32 percent of the state's total annual rainfall is received from this monsoon, which hit Kerala and the Northeast on Tuesday, two days ahead of its scheduled arrival.

TNAU's Agro Climatic Research Centre in its forecast said Salem, Namakkal, Dharmapuri, Krishnagiri, and Nilgiris districts are expected to receive normal rainfall.

Chennai, Coimbatore, Cuddalore, Dindigul, Erode, Kancheepuram, Kanyakumari, Madurai, Perambalur, Pudukottai, Sivagangai, Theni, Tiruvallur, Tiruvannamalai, Villupurum and Vellore districts are also expected to receive normal rainfall during the monsoon, it said.

Deficit rainfall is expected in Nagapattinam, Ramanathapuram, Tirunelveli, Tutucorin, Tiruppur, Karur, Virudhunagar, Tiruchirappali, Thanjavur, Ariyalur and Tiruvarur districts, the release said.

TNAU advised deficit rainfall districts to follow normal cropping pattern with existing agro-technologies along with weather based agro advisories in normal rainfall districts.

They should use the forecast to make strategic decisions to raise short duration, less water requiring crops with available irrigation facilities, it said.

TNAU said that district level rainfall forecast for June to September was developed based on Southern Oscillation Index of the summer season and sea surface temperature values of the east Pacific ocean using Australian Rainman International V.4.3. software.

The historical rainfall data collected from university stations was used to represent the basis for district rainfall data set, the release said, adding that in the absence of data from research stations in a particular district, data from Rainman software were used alternatively.