Northeast monsoon arrived over the south peninsular region, including Tamil Nadu and Kerala, on Wednesday. While the monsoon made a weak onset over the State, it is expected to pick up pace in a few days, according to the Meteorological Department.
Northeasterly winds and a cyclonic circulation over southwest Bay of Bengal off north Tamil Nadu coast aided the commencement of NE monsoon. After an extended stay, Southwest monsoon retreated from the country on Wednesday and paved the way for the onset of NE monsoon.
Tamil Nadu receives an average of 44 cm of rainfall during the NE monsoon between October and December.
S.Balachandran, deputy director of meteorology, Chennai said NE monsoon commenced with sporadic rainfall over south Tamil Nadu and coastal areas and did not cover the entire region. Melur in Madurai district received 6 cm of rainfall, the highest amount received during the past 24 hours ending at 8.30 a.m. on Wednesday. In Chennai district, Nungambakkkam and Sholinganalllur received 1 cm of rainfall.
“There was no significant weather system to bring heavy rainfall. Cyclone over Pacific Ocean too was drawing moisture away. The influence of the global weather pattern, La Nina, could also be a reason for the weak start of the monsoon,” he said. Though the average onset date is around October 20, a deviation of seven or eight days is still considered normal.
For the next two or three days, the Meteorological Department has forecast light to moderate rainfall over few places of south TN and one or two places of northern parts of the State and Puducherry. There may be heavy rains over one or two areas in Tirunelveli, Tenkasi and Virudhunagar districts.
In Chennai too, light to moderate rains or thundershowers are likely to occur in some areas till Friday. It may experience a day temperature of 30 degree Celsius for two days.