Cyclone Vardah
Cyclone Vardah devastated property in ChennaiIANS

Tamil Nadu is on red alert after the Indian Meteorological Department issued a notice that low-pressure is forming over the Bay of Bengal and is expected to turn into Cyclone Fani which will hit the state between April 30 and May 1.

Chennai and many other parts of Tamil Nadu are expected to receive heavy to very heavy rainfall on Sunday and extremely heavy rainfall in isolated areas.

Other parts of South India is also expected to receive rainfall, including Kerala where Idukki, Malappuram, Thrissur and Ernakulam, is expected to receive heavy rains on Monday, states The Times of India.

The wind speeds over the Bay of Bengal, before hitting the Tamil Nadu coastline, will range from 30-50 kmph.

The IMD had said on Thursday, "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."

IMD Chennai's director S Balachandran had said that while Chennai and neighbouring localities are expected to receive heavy rainfall on Sunday, there may be changes.

Other meteorologists called out the IMD for issuing a red alert. "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," an official at the Regional Meteorological Centre (RMC) was quoted as saying by TOI.

Pradeep John, who has a Facebook page known as Tamil Nadu Weatherman, explained the forecast in a post with an image.

cyclone fani
Facebook/Tamil Nadu Weatherman

He wrote, "Slowly consensus is coming in from all numerical weather models. The ridge building up will block the cyclone going away. So it has to be TN/SAP or fizzling out curving away in open seas. These are only two scenarios."

"As the forecasted cyclone is expected to stall because of the ridge, this is going to dump lots and lots and lots of rains where ever it is going to cross and surrounding areas. Droughts to floods can happen in some areas if this going to cross Tamil Nadu. One more day needed to accurately say this is going to be for Tami Nadu. It is as of 60% favourable to Tamil Nadu. It's always a thrill tracking these nature's wonders/monsters. My heartbeats rises seeing each models runs (praying Tamil Nadu ku vanthudu). This cyclone if it crosses near Chennai, it will solve all our water problems and all our lakes will be filled up to the brim. Sadly it will be powerful, we need to sacrifice some of the trees for the water sake," he added.