This year might be one of the few years in the past three decades when the northeast monsoon failed to bring adequate rainfall to the city.
Chennai has so far recorded 98 cm of rainfall against the annual average of 140 cm. For this season, since October, the rainfall which is 55 cm, falls short by 33 per cent.
A trough over the Bay of Bengal is bound to bring light to moderate rain to the city and its neighbourhood during the next two days and gusty winds will prevail. However, it may not be sufficient to bridge the gap in rains, say officials of the meteorological department. Officials added that though it was not a poor record of rainfall, the long dry spell had created a sense of a rainless year. Chennai has not received substantial showers after December 4.
Y.E.A. Raj, deputy director general of meteorology, Regional Meteorological Centre, Chennai, said the city had registered less than 100 cm of rain during four years in the past three decades — in 1982 (87 cm), 1986 and 1998 (98 cm) and 2003 (74 cm). Chennai has enjoyed consecutive years of excess or normal rainfall since 2004. “This is an unprecedented phenomenon of northeast monsoon. Our records indicate that we have not had such a weather pattern since 1871. Unfortunately, the weather pattern was broken this year with deficit in rainfall,” he said.
During the previous years when the city recorded less rainfall, the southwest monsoon bridged the shortfall. However, rains between June and September this year fell short by nearly 7 cm of the season’s normal of 41 cm.
Though windy days are not unusual during the northeast monsoon, the link between winds and reduction of rainy days has to be studied, said officials.
S.R. Ramanan, director of Area Cyclone Warning Centre, said that Chennai may get only 2 cm or 3 cm of rain during this spell and it is expected to reduce by Sunday. Delta districts are expected to record heavy rainfall.
Officials of the meteorological department said the weather models indicate that there may be another rain spell around January 6. But, it needs to be monitored.