Marina Beach in Chennai

CHENNAI: Parts of Tamil Nadu can expect very heavy rain from Sunday as a well marked low pressure has formed in the Bay of Bengal and is likely to intensify into a depression in the next 24 hours and further into a cyclonic storm in the subsequent 24 hours. Wind speed is expected to be between 30 and 50km/hour, the Indian Meteorological Department ( IMD ) said on Thursday.

However, it’s not yet clear where the rain will occur as the low pressure is yet to develop into a cyclonic storm. Bangladesh has named the prospective cyclone ‘Fani’.

IMD Chennai, director S Balachandran said that as of now the north coastal districts, including Chennai, are likely to get rain. “But there may be changes,” he added.

The IMD on Thursday forecast heavy to very heavy rain in a few places and extremely heavy rain at isolated places over coastal Tamil Nadu as the weather system brewing over the southeast Bay of Bengal is likely to intensify into a cyclonic storm in the next 48 hours. “Heavy rainfall is likely to occur for sure on April 28 and 29 but it is too early to say whether it will rain in the south or north coastal area or in interior parts of the state because the system has not developed into a cyclone,” an IMD official said.

‘Thunderstorm with gusty winds, lightning in isolated places’

The weatherman issued the rainfall warning under a ‘red’ legend, which requires the district administrations to ‘take action’ on April 30 and May 1, when the cyclone is expected to move closer to the coast.

IMD has forecast “thunderstorm with gusty winds (50-60 Kmph) and lightning is likely to occur at isolated places over Tamil Nadu” on April 28.

“It is wrong to call it a ‘red alert’. Warnings are issued under various colour codes to inform the district administration to be prepared or take action. Since extremely heavy rain is forecast, it was marked under red colour,” a Regional Meteorological Centre (RMC) official here told TOI.

Private weather blogger Pradeep John in a pre- ‘Fani’ analysis says that an April 1966 cyclone was the last one to move towards TN. It made landfall between Chennai and Nagapatinam, but far away from Chennai.

He also says "In the end how close the cyclone is going to come to the north TN coast (Kancheepuram-Tiruvallur-Chennai) and turn away will define our rains."

The IMD said a well-marked low pressure lay over the east equatorial Indian Ocean and adjoining southeast Bay of Bengal.

It is very likely to intensify into a depression during the next 24 hours over east equatorial Indian Ocean and adjoining central parts of south Bay of Bengal and into a cyclonic storm during subsequent 24 hours over southwest Bay of Bengal and adjoining equatorial Indian Ocean.



In Video: Cyclone Fani: IMD predicts heavy rain in parts of Tamil Nadu, including Chennai