A 'red alert' - for extreme to very extreme rainfall for today and tomorrow - has been issued in 20 districts in Tamil Nadu, including Chennai, according to NDTV.com following the emergence of a low-pressure area over the Bay of Bengal that aggravated into depression. The portal adds, “It is expected to move west-northwest and reach Tamil Nadu's northern coast by tomorrow morning, leading to heavy to very rainfall over parts of the southern state as well as neighbouring Puducherry and Karaikal.”

The Tamil Nadu government has already formed 434 'siren towers' to keep authorities on alert on floods and other exigencies, and is also working in tandem with telecom networks “to ensure mobile connectivity is not affected; 50 cellular phone towers (on wheels) are ready for use.”

In Chennai 46 boats and JCBs, more than 500 giant motor pumps have been installed for rescue operations, Greater Chennai Commissioner Gagandeep Singh Bedi told NDTV, adding, “169 relief centres are operational and floods from rainfall earlier this week have been cleared in 216 of around 400 areas. 14 of 16 flooded subways have also been cleared.”

Free food will be supplied from the Amma canteens.