Early this month, two low-pressure systems developed in the Bay of Bengal below Myanmar and Bangladesh, the second of them going on to form what is known in meteorological terms as a "depression". This attracted winds from the high-pressure regions of the southern Indian Ocean 2,500 km away to the south-west. The swollen monsoon clouds off the Indian coast above Sri Lanka reacted, heading swiftly towards the north-east before coming up hard against a mountain formation called the Western Ghats.

Their progress halted, the swirling moisture-filled clouds dumped a good part of their burden where they stood: For the week from Aug 8, Kerala, a tourist haven facing the Arabian Sea famous for its picturesque lagoons and Ayurvedic massages, had more than 3.5 times the normal rainfall.