Chennai: In 2013, Tamil Nadu experienced its poorest north east monsoon in 18 years. The state recorded a 32 per cent deficit mean rainfall at 29.5 cm compared to a normal of 43.5 cm for this season starting October 1 to December 26. WeatherÂmen expect the season to officially close with a similar deficit percentage.
“The last time we faced such a poor NE monsoon was in 1995, when the state recorded 46 per cent deficit. Since then, the deficit percentage had not touched 32,” said Dr Y. E. A. Raj, deputy director general of meteorology, Regional Meteorological Centre, Chennai.
In the years 2000 and 2001, Tamil Nadu experienced 28 per cent and 21 per cent deficit rains respectively. “From then on, we had continuously positive years, when the state received normal or substantial rainfall until 2012, when we ended up minus 16 per cent,” he said.
Barring five districts —- Dharmapuri (-4 per cent), Kanyakumari (-2 per cent), Krishnagiri (-18 per cent), Nilgiris (-15 per cent) and Tirunelveli (-9 per cent) —- all the other districts, including Chennai, recorded a deficit rainfall of over 20 per cent. Chennai is currently staring at 40 per cent deficit rains at 46.4 cm compared to a normal of 77 cm.
Noting that such poor rains were unexpected, amateur weatherman and Ham radio operator K. Rajesh said that the cold winds from the north started earlier this year, thereby deflecting the monsoon from Tamil Nadu.
“It affected the formation of low pressure areas as the temperature gradient between land and sea was not effective,” he added. Rajesh said that there might be some rains around January 20 when a low-pressure system would form in the Bay of Bengal. Dr Raj too added that there are chances for the NE monsoon to spill over to January. “While it withdraws by December-end over coastal TN, there is always a window of plus or minus 18 days,” he added.
