Nungambakkam's 24hr spell highest in 10 years

Chennai: Will more rainfall records tumble this month? The 14cm recorded in 24 hours on Oct 15-16 was the highest since 2014 for Nungambakkam where the monthly average of 30cm has already been recorded. But in seven of the past 10 years, Nungambakkam has recorded the highest 24-hour rainfall in the second half of the month. So can we expect more rain?

IMD has forecast normal to above-normal rainfall in Oct over Chennai and most parts of Tamil Nadu, except for some western districts and the southernmost areas. Private forecasters and bloggers expect light spells every other day, and another weather system, which may form over the Andaman Sea, could bring intense rain.

For the next 48 hours, the city and suburbs can expect light to moderate rain with thunderstorms and lightning over some areas. Maximum and minimum temperatures may be around 33-34°C and 25-26°C.

"There are chances of light to moderate thunderstorm-type activity in the city for the next two days. A cyclonic circulation may bring some rainfall around Oct 20-21, but it is not clear yet if it will bring rainfall to Chennai. For north coastal Tamil Nadu, including Chennai, widespread rain can happen only if there is a sea-bound weather system," said N Senthamarai Kannan, director, regional weather forecasting centre, IMD.

Since Oct 1, Chennai subdivision recorded 29cm of rain, around 214% excess. The previous highest 24-hour rainfall was 16cm recorded on Oct 18, 2014. The all-time highest 24-hour rainfall record is 28cm on Oct 22, 1969. Oct on average has 10.5 rainy days.

A day after the depression over the Bay of Bengal weakened and moved inland, weather watchers started tracking the next system, which may form over the Andaman Sea around Oct 24. "Models show a weak circulation coming from the Indochina region. If it develops into a low-pressure area and does not strengthen further, the system may approach the south AP-north TN coast. If it intensifies further, the system may move towards Orissa or West Bengal," said blogger Pradeep John.

Mahesh Palawat, chief meteorologist, Skymet Weather, said day temperatures may rise marginally if the system moves northwards, as the winds would be concentrated around it.