With a depression lurking to the south of Kanyakumari and west of Sri Lanka, the stage is set for a rare weather system of near-cyclonic strength to develop in the Comorin Sea/Lakshadweep Sea.

The system was located 360 km east-south-east of Kanyakumari on Wednesday afternoon, marked by a humongous parcel of cloud twice the size of Sri Lanka just east-south-east of the island nation.

Deep depression

The India Met Department (IMD) expects the system to ramp up to a deep depression (next only to cyclone strength) in the Comorin Sea by Thursday, while tracking in a west-north-west direction.

This would see it graze the Kanyakumari-Nagercoil-Thiruvananthapuram coast before heading towards Lakshadweep. The European Centre for Medium-Range Weather Forecasts sees scope for further intensification of the system.

The US Joint Typhoon Warning Centre sees the system moving within earshot of Kanyakumari-Nagercoil, with warm seawaters (way beyond the threshold 27.5 deg Celsius) expected to fuel its growth.

The IMD has issued heavy to very heavy rain forecast for select stations over the south Tamil Nadu and Kerala coasts and Lakshadweep over the next two days accompanied by warning to fishermen along these coasts.

Likely cyclone?

A number of other global models saw a powerful cyclone developing in the East-Central Arabian Sea (away from the Kerala coast) but turning towards east-north-east, guided by an incoming western disturbance.

Some of these indicated that this track would take it towards Mumbai-Gujarat coast after weakening into a low-pressure area. Some others said the system might just stop short of caressing the coast and fade out in the Central Arabian Sea.

Wind-field projections by the IMD shows the system stagnating off the Karnataka-Goa coast and gradually fading out by December 8.

Given the movement mostly out into the sea, the gains in terms of rainfall for the peninsula are limited except the southern parts of Kerala and Tamil Nadu in the initial phases.

Successor depression

As expected, Sri Lanka would benefit most out of the system since its outer bands have been lashing its southern flanks from its location in the Equatorial Indian Ocean. It later crossed the island nation dumping heavy rain over its geography.

Meanwhile, forecasters are eagerly watching a disturbance over Malay Peninsula, which the IMD expects to cross into South Andaman Sea to convert as a low-pressure area by Thursday.

This, it is then believed, will intensify into a depression. The JTWC tended to agree, seeing scope for ‘significant development’ of the system in the neighbouring Bay of Bengal.

Here again, most models indicate development into a tropical cyclone and a track aiming the Tamil Nadu-Andhra Pradesh coasts, though they differed in their perceptions with regard to the actual point of landfall.