There is still a month to go for the northeast monsoon to withdraw, but Chennai has already received 170 cm rainfall this year, which is 30 cm more than the annual average.
Officials of the Meteorological department said the increase has been on account of the rainfall that the city and suburbs have been receiving since September.
They added that the current spell would continue for two more days.
Though the deep depression has drifted towards Oman coast over the Arabian Sea, the system still has impact over the Bay of Bengal. This would bring more rainfall over southern parts of the State and coastal districts, including Chennai.
The rainfall would reduce by Saturday or Sunday, the officials added.
This year, the city received copious rainfall despite not experiencing any deep depression or cyclonic storms, the officials added.
The city has so far recorded 72 cm of rainfall during the northeast monsoon, since October 1, which is 3 cm more than normal.
Meenambakkam has received bountiful rainfall with 78 cm, which is 16 cm more than the average. So far this month, Chennai received nearly 46 cm against the average of 35 cm.
Y.E.A. Raj, Deputy Director General of Meteorology, Regional Meteorological Centre, Chennai, said the occurrence of cyclonic storms over the Bay of Bengal during northeast monsoon has reduced in the past four or five years. Instead, deep depressions and cyclonic storms over Arabian Sea have contributed to the city's rainfall.
A similar pattern was being experienced this season too. Well-marked trough, feeble low pressure areas over the Bay of Bengal and strong easterlies were enough to cause downpour in the past two months, he added.
Chennai district, including the suburbs, has recorded 69 cm of rainfall, an excess of 10 per cent than the average, so far in the northeast monsoon. This would be the eighth year in succession that the city has had a good monsoon, he said.
While the mean number of rainy days in November is only 10, the city experienced rainfall for 14 days this month, he added.
The department forecasts one or two spells of rain or thundershowers in some areas on Wednesday.
