A trough of lower pressure (as distinct from a low-pressure area) lay in wait on Wednesday over the Equatorial Indian Ocean and adjoining South-East Bay of Bengal, topped up a cyclonic circulation.

This circulation is expected to descend to lower levels to set up a conventional low-pressure area or ‘low’ over the Equatorial Indian Ocean and adjoining central parts of South Bay of Bengal (off South-East Sri Lanka) on Thursday.

Maintains watch

The India Met Department (IMD) maintained the watch for its intensification into a depression by Friday, following which it would move to the north-west along and off the East Coast of Sri Lanka towards Tamil Nadu, and intensify into a tropical cyclone by Sunday.

Importantly, it also warned that the cyclone could intensify further before crossing the North Tamil Nadu coast around Tuesday (April 30), thus taking a call for the first time on the likely landfall area.

This would mean that Tamil Nadu, along with Sri Lanka, needs to brace for a major cyclone early into the pre-monsoon season threatening the coast with gale-force winds speeding up to 100 km/hr.

This could generate ‘very rough’/‘high’ sea conditions (waves rising up to 30 ft ) over the South Bay of Bengal. Widespread rainfall with isolated heavy to extremely heavy rains are forecast for Tamil Nadu and adjoining Andhra Pradesh.

Fairly widespread rainfall with isolated heavy falls and squally winds are also likely over Kerala and Coastal Karnataka. The cyclone and the heavy rain it brings in would be a god-send for the parched areas in the South Peninsula.

Heavy rain in offing

The GEFS model of the US National Centre for Environmental Prediction says that post landfall on the Tamil Nadu coast, the remnant would emerge back into the Bay off the Andhra Pradesh coast and set up a second cyclone.

This would then tear its way diagonally across the open Bay towards Myanmar/Bangladesh in a track not unfamiliar for cyclones forming in the Bay during the pre-monsoon season.

The European Centre for Medium-Range Weather Forecasts, though, takes the powerful cyclone very close towards the Andhra Pradesh coast by Wednesday without indicating a final landfall area.

There is a third international model forecast that favours the cyclone cutting its way into the peninsula and weakening, but meandering towards the Kerala-Coastal Karnataka to step out into South-East Arabian Sea where it would find fresh traction.

Meanwhile, squally winds with speeds of up to 50 km/hr and gusting to 60 km/hr are forecast to start lashing the Tamil Nadu coast from Sunday. Heavy to very heavy rains are likely at isolated places over Tamil Nadu and Puducherry.

Related Topics