High swells prompt red alert and coastal restrictions in Kerala

High-period swell waves from the southern Indian Ocean reached India’s southern tip on Saturday, prompting a red alert and restrictions along Kerala’s coast. The Kerala State Disaster Management Authority said waves with periods of 20 to 24 seconds and heights of up to 1.5 metres reached parts of Kanyakumari. Smaller precursor waves had begun reaching Kerala’s coast.

The effect of the swell surge, known as Kallakadal, was expected to become more pronounced from Saturday night, particularly during high tide. The system was forecast to interact with coastal areas until 2.30 a.m. on September 28.

Authorities warned that low-lying coastal locations could be inundated. Kerala suspended recreational and fishing activities until September 28, and a cell-broadcast warning was sent to residents in coastal parts of the State. The Indian National Centre for Ocean Information Services issued a swell-surge warning covering Kerala, southern Tamil Nadu and Lakshadweep from September 26 to 28.

INCOIS said the event originated about 10,000 kilometres from the Indian coast in the southern Indian Ocean on September 20. It has since been moving towards the northern Indian Ocean, generating high-energy swells with a peak wave period of about 23 seconds. The combination of long-period swells and high tides could cause flooding in low-lying coastal areas of Kerala, southern Tamil Nadu and Lakshadweep during the forecast period.

Fishermen and coastal residents were told to remain alert for intermittent seawater surges near beaches and shorelines. People were advised not to operate small vessels close to shore, while boats were instructed to be anchored with sufficient separation to prevent collisions and damage. Tourism and other operational or recreational activities along beaches and nearshore areas were also suspended under the warning.