Chennai: In 10 yrs, city’s average rainfall up to 10-15%
November 8, 2009 Leave a comment
CHENNAI: For the city’s residents there is welcome news. Indications are that Chennai will receive good rainfall from this year’s northeast monsoon.
The rain should substantially fill up the lakes and feeder tanks and recharge groundwater as well.
Between Friday and Saturday, Red Hills and Chembarambakkam received 140 mm of rain each, while Cholavaram recorded 110 mm and Ponneri 130 mm.
With the Nungambakkam observatory recording 60 mm of rainfall for 12 hours ending 5.30 on Saturday evening, Chennai received more than 15 cm rainfall over the past two days. The city, which was facing a deficit rainfall of nearly 99% a month ago, is close to wiping out that shortfall. From October 1 to November 7, Nungambakkam observatory recorded 380 mm or rainfall.
The bountiful rain is an indication that there has been a consistent increase in the annual average rainfall in the city over the past 10 years. "Earlier, the annual long-term annual average was 1,220 mm, but based on a rainfall study dating from 1969 to 2008, the average has now gone up to 1,409 mm, an increase of 10% to 15%, " said Y E A Raj, deputy director general, Regional Meteorological Centre (RMC). "We are also experiencing this year a classic northeast monsoon where only easterly winds prevail," he added.
The presence of a trough over the south and central Bay of Bengal has resulted in a vigourous monsoon, and more rains have been forecast till November 10. The presence of another weak trough, south of Cape Comorin, is likely to keep the monsoon active beyond November 13.
Last November, the city received 556 mm of rainfall, and in 2007 it was 95 mm. "There are indications that this monsoon will be a very good one for the city, " added Met officials. The city may receive a respite for a couple of days starting November 10, but by 13th, the monsoon will turn intense again.