Swell waves reach west coast; red alert continues along Keralam coast

High-period swell waves from the southern Indian Ocean reached the southern tip of the country on Saturday and began interacting with the coastal regions, the Kerala State Disaster Management Authority (KSDMA) confirmed.

Swell waves with a period of 20 to 24 seconds and a height of up to 1.5 metres reportedly hit parts of Kanyakumari, while precursor waves — minor wave patterns that travel ahead of the main swell — began reaching the Keralam coast, said the KSDMA.

Possibility of inundation

The impact of the swell surge (Kallakadal) is expected to become more pronounced from Saturday night, particularly during the high-tide period. The swell system is expected to continue interacting with the coast and coastal regions until 2.30 a.m. on September 28, with a possibility of inundation in low-lying coastal areas of Keralam.

A red alert has been issued along the Keralam coast suspending all recreational and fishing activities until September 28, while a cell-broadcast warning message was sent to mobile phones of people across the coastal regions of the State on Friday night.

The Indian National Centre for Ocean Information Services (INCOIS), which provides forecasts on ocean conditions in the seas surrounding India during extreme weather events such as high waves, swells and cyclones, has issued a swell surge warning for Keralam, southern Tamil Nadu and Lakshadweep from September 26 to 28.

According to INCOIS, the event originated approximately 10,000 km from the Indian coast in the southern Indian Ocean on September 20 and is gradually propagating towards the northern Indian Ocean. This has resulted in the propagation of high-energy swells, with a peak wave period of around 23 seconds, towards the Indian coastal regions. These long-period swells, combined with high-tide conditions, may cause coastal flooding in low-lying areas of Keralam, the southern Tamil Nadu districts and the Lakshadweep islands during the forecast period.

Advisory to fishers

Fishermen and coastal residents in Keralam have been advised to remain alert to intermittent surges of seawater in nearshore and beach areas, particularly in low-lying locations. The public and fishermen have been advised not to operate small vessels close to shore. Boats should be anchored at a safe distance from one another to prevent collisions and damage. All operational and recreational activities, including tourism activities, along the beaches and nearshore areas have also been suspended.