Context:  The Indian National Centre for Ocean Information Services (INCOIS) has forecasted that swell waves might hit several Indian coastal areas in the upcoming days.

What are Swell Waves?

• They are high sea waves that are formed by an ocean swell.
• Ocean swells occur due to distant storms like hurricanes and not due to the local winds.
•  During such storms, huge energy transfer takes place from the air into the water, leading to the formation of very high waves.
• Such waves can travel thousands of kilometres from the storm centre until they strike shore.

Efforts to Mitigate It:

• To forecast swell waves, INCOIS launched the Swell Surge Forecast System in 2020 which can give forewarning seven days in advance.
• In March 2024, swell waves led to flooding in several areas of Kerala. Such flooding events are called Kallakkadal in Kerala.