City sees wettest July since 2007

CHENNAI: Chennaiites are finding this month unusual and they are not complaining. Not only has the monthly average temperature fallen by more than five degrees Celsius (from 34 to 28.9), the days are getting good rains.
The weatherman attributes this monsoon flavour' to low pressure formations and some other favourable meteorological systems.
"The presence of an upper air cyclonic circulation over the west-central Bay with a southern tilt, a north-south trough over Chennai and a weak upper air system have the potential to bring scattered rainfall over the next two days," said YEA Raj, deputy director-general, Regional Meteorological Centre, Chennai.
The cyclonic circulation may develop into a low pressure zone followed by depression, and during the formative stage there will be a good amount of rainfall over many areas of the state, Raj added. The trough has been present for many days during this month, resulting in light showers. For the common man, it just means he has to take out the umbrella or get drenched, happily. "This evening was almost like a monsoon day with intermittent drizzle. This is a pleasant surprise in the city which sees an extended summer till as late as October," says Santhosh V, who had to cancel an appointment on Rajaji Salai.
His observation is substantiated by rainfall statistics: Chennai gets an average of 126 mm rain in July, but the first 20 days of this month have already registered 110 mm of rainfall. Unlike Coimbatore and Kanyakumari, which are in the windward side of the southwest monsoon, most areas do not benefit from good precipitation. However, between June 1 and July 20, the state has received 151.5 mm of rain, against the normal 85.3 mm, an excess of 78%. Chennai district registered a 68% increase in rainfall in the same period, realising 211 mm.
"With the promise of more rains, Chennai may breach the 200-mm mark for the month once again," said Raj. While July 2008 and 2009 were comparatively drier, receiving 29 mm and 37 mm, the city has recorded good rains in July in the past. In 1975, it received 205 mm, in 1981 224 mm, in 2001 270 mm and in 2007 244 mm.