CHENNAI: Cyclone Nivar has left Chennai with an excess of 36% rain for the season so far, but weathermen say the active phase of the northeast monsoon, which ends in December, may be far from over. There may be back-to-back weather systems brewing over the Bay of Bengal that could bring more rain to the city and several parts of the state, they say.
India Meteorological Department (IMD) has forecast that a low-pressure area may form around November 29. Weather trackers said there are chances of it intensifying into a cyclonic storm before hitting the TN coast. Then by December 11, there may be another system forming and moving towards the state.
On Thursday, IMD said a low-pressure area is likely to form over the south Bay of Bengal around November 29. It is likely to become more marked and move westwards towards south Tamil Nadu. N Puviarasan, director, Area Cyclone Warning Centre, IMD said they are closely monitoring the development and that it was too early to forecast how the system may evolve.
However experts said the system may develop, albeit a weak one, and could cross the delta region and may bring widespread rain to the coastal areas including Chennai on December 1 and 2. The system may be weak because conditions like a cool sea surface after the upwelling caused by cyclone Nivar and a weak Madden-Julian Oscilla-tion, an eastward moving disturbance of clouds, rainfall, winds and pressure that travels across the tropics, are un-favourable for its intensification over the sea.
There may also not be long periods of dry spell before the next active rounds of rainfall from the weather system, as IMD has forecast light rain over the city for the next 24 hours.
Weather blogger Pradeep John said global weather shows that another system may form around December eight or 11 and bring rain but too ear-ly to assess how the system may evolve. "Nungambakkam has recorded nearly 839mm against an average 857mm for northeast monsoon sea-son. Now we also have two other systems that may bring rain to Chennai as well as to several other districts of Tamil Nadu. There is no doubt we will end this monsoon season with a large excess," he said.