Depression over the southwest Bay of Bengal likely to cause showers
In what could be one of the last spells of northeast monsoon, Chennai is likely to receive light rains from Monday, according to Meteorology department officials.
Several places along south coastal Tamil Nadu and parts of the northern coastal districts may receive rains due to a depression over southwest Bay of Bengal, lying about 470 km southeast of Nagapattinam and 250 km east of Trincomalee on Saturday.
The department is not rushing to declare the withdrawal of the monsoon from the State as this rain spell is expected to last till Wednesday. Officials of the meteorological department said that though it may cross the Sri Lanka coast by Sunday evening, it is expected to bring some rainfall over the state.
Squally winds would blow up to a speed of 65 km per hour and off Tamil Nadu coast and the sea would be rough, an official said.
Y.E.A. Raj, deputy director general of meteorology, Regional Meteorological Centre, said that weather models are indicating that another system is approaching the coast. “We will wait till Pongal before we declare the end of the monsoon,” he said.
Chennai recorded 44 cm of rainfall against the seasonal average of 84 cm between October and December last year. Meenambakkam received a slightly better amount, getting 48 cm against its seasonal average of 78 cm. “In recent years, the spillover of northeast monsoon to January has become common. Chennai has recorded seven systems, be it depression or a cyclonic storms, in January over the past 50 years. But, many of the systems have dissipated before crossing the coast,” he said.
Citing weather data from 1871, Mr. Raj said northeast monsoon rainfall has spilled over to January of the next year in 33 per cent of the years. On the existing system over the Bay of Bengal, he said Chennai would experience warmer nights as minimum temperature would be above normal due to moisture incursion.
The department forecasts that the maximum and minimum temperature would be around 29 and 23 degree Celsius till Monday.