With just 10 days to go for the northeast monsoon to officially end, rainfall activity may largely remain subdued. However, some places across the State may receive light rainfall till Friday.
An upper air cyclonic circulation that lies over the Comorin area and its neighbourhood will influence light to moderate rainfall in some parts of south Tamil Nadu, including Tirunelveli, Virudhunagar, Dindigul and Madurai.
S. Balachandran, Director, Area Cyclone Warning Centre, said the easterlies, a seasonal wind, have gained strength. A few places in north Tamil Nadu, including Vellore, Chennai and Dharmapuri, may get rain. There may be heavy rainfall in isolated places in south Tamil Nadu like on Wednesday when Rameswaram received 8 cm. Chennai may continue to experience gusty winds and light rain in a few areas.
Meanwhile, the India Meteorological Department’s weather models indicate that a low pressure area is likely to develop over the south Andaman sea and the adjoining southeast Bay of Bengal around Christmas. On the possible weather system around December 25, Mr. Balachandran said it was unclear whether it would result in rain over Tamil Nadu. “We are monitoring the system for its impact over the region,” he said.
Lull in rainfall
The State has been experiencing a lull in rainfall since early this month. This has pushed the State’s seasonal rainfall to a deficit. While the State is still in need of 6% rainfall to match its seasonal rainfall of 42.2 cm, the department still considers this to be normal.
Only when the shortfall crosses 20% is the the monsoon considered deficient. Though there has not been widespread rain for the past few days, Chennai district’s monsoon rainfall is at 94 cm, which exceeds the average by 24%. Both Nungambakkam and Meenambakkam have already received more than their share of annual average rainfall. While Nungambakkam has recorded 149 cm against its annual normal of 140 cm, Meenambakkam has registered 161 cm against its yearly quota of 138 cm.
The possibility of rain in the next few days would be the deciding factor for seasonal rainfall over the State to improve, officials said.