September got off to a wet start with showers soaking many parts of the city on Friday morning. Pleasant weather, accompanied by intermittent showers, are here to stay for four more days over the State.
Unlike the previous days, when rains drenched the city mostly after sunset, residents woke up to northeast monsoon-like weather with a drizzle and murky skies on Friday. Though loud thunder signalled heavy rains, only mild showers were recorded, that too for only a few hours, in the morning. An upper air cyclonic circulation that lies over the southwest Bay of Bengal off the south Sri Lanka coast is one of the reasons for the rain and murky sky.
During the past 24 hours ending 8.30 am on Friday, Sivagiri in Tirunelveli district received the highest volume of rainfall —11 cm. Officials of the Meteorological department said the system is drawing moisture both from the Bay of Bengal and Arabian sea. Rain would be widespread and last for four days due to a combination of factors.
S. Balachandran, director of the Area Cyclone Warning Centre, said as the system is expected to move westwards in the coming days, it will lead to moderate rainfall in most parts of the State. One or two places in southern Tamil Nadu may receive heavy rainfall on Saturday.
The upper air cyclonic circulation associated with easterly winds laden with moisture spreading over the region would bring more rain over Tamil Nadu. The interaction between hot westerly winds at a lower level of the atmosphere and cool easterly winds at a higher level above 5 km from the earth would also help sustain moderate showers over most places in the State, officials said.
Showers resumed in the evening. Areas such as Ambattur, Velachery and Mogappair received good rain. Convective activity triggered by the sea breeze will also influence localised rain for four more days. Thunder clouds formed after the heating of land usually last for a few hours and do not cause flooding, officials added.
The Meteorological department forecasts moderate showers for Chennai too during evening or night hours.
