Tamil Nadu is likely to have normal rainfall during the northeast monsoon this year, according to the India Meteorological Department.
In its long-range forecast for the northeast monsoon (October to December), the IMD has predicted normal rainfall in the southern peninsular region, including Tamil Nadu.
It may vary between 89% and 111% of the long period average (LPA) of 33.8 cm in the southern peninsular India. (LPA is the average rainfall recorded between 1961 and 2010).
The outlook is based on the statistical forecasting system and the multi-model ensemble-based forecast system that incorporates global climate models, too.
S. Balachandran, Deputy Director-General of Meteorology, Chennai, said both the seasonal and October rainfall in the State is likely to be normal. Tamil Nadu receives an average of 44 cm during the northeast monsoon. The models have their own limitations for long-range forecasts at the State level for the northeast monsoon.
The IMD has also forecast delayed withdrawal of the southwest monsoon. It may begin to withdraw from north-west India from October 6. The State has recorded 39.3 cm, which is 17% in excess of its average rainfall, during the southwest monsoon.
Mr. Balachandran noted that there would be an increase in rainfall from Friday. Most places in the State may experience light to moderate rain till October 4 owing to an easterly trough. On Friday, one or two places in southern districts, like Theni, and the Cauvery delta districts may receive heavy rain.
On Thursday, several parts of Chennai recorded light rain. Ennore received nearly 5 cm, and the rain gauges at Taramani, Villivakkam and MRC Nagar recorded nearly 1 cm till 5.30 p.m. The IMD forecast thunderstorms with light to moderate rain in some areas of Chennai till Saturday.
