The Hindu Business Line : Brewing Bay system downgraded

THE National Centre for Medium Range Weather Forecasting (NCMRWF) on Friday downgraded the brewing weather system over southeast Bay of Bengal to a `cyclonic circulation'.

Conditions continue to be favourable for the formation of the system around Sunday/Monday, the NCMRWF said in its update on Friday.

The sea surface is warm in the southeast Bay and the amplitude of the westerly trough that blew away predecessor Tropical Depression 07B to the northeast has waned, Dr K.J. Ramesh of the NCMRWF said.

The Inter Tropical Convergence Zone (ITCZ) has shifted down closer to the Equator, a condition that presages nil activity or lull in the Indian Ocean basin. But purely localised factors have in the past led the feeblest of systems to gather momentum on their own and pull north-northwest. The ITCZ gets yanked to the north in the process, to be able to supply the system with fuel to intensify and even grow as a cyclone.

Tropical Cyclone Fanoos was the most recent example, Dr Ramesh said. Given this scenario, the brewing weather system would be watched closely, he said.

The University of Wisconsin-Madison graphics on Friday revealed that wind shear tendency values were favourable on Friday along a presumable path the system was propagating, and also around extreme southeast Bay and the Andamans.

This was not the case with the southwest Bay, even though extreme southwest Bay and adjoining Sri Lankan waters had turned favourable lately.

But positive warming anomalies were returning to the southeast Bay and, to some extent, the south-central Bay, too. According to Dr Ramesh, there was no indication of a killer westerly system approaching in the near term either.

Meanwhile, the NCMRWF update said the well-marked low-pressure area over the east-central Bay of Bengal (remnant of 07B) had weakened to a `low' during the last 24 hours.