Fresh cyclonic circulation over Bay by weekend

Thiruvananthapuram--The weatherman had forcasted a  cyclonic storm over the Bay of Bengal. The wet conditions in the contiguous meteorological subdivisions of Coastal Andhra Pradesh, Tamil Nadu and Pondicherry are tipped to spill over into the next week with a rain alert being mounted for a third day on a trot.

In its forecast on Thursday, the National Centre for Medium Range Weather Forecasting (NCMRWF) has said that a fresh cyclonic circulation is set to take shape over southeast Bay of Bengal by Saturday/Sunday.

Speaking to Business Line, Dr K.J. Ramesh of the NCMRWF, said that the east-west shear zone extending from the Bay of Bengal across the peninsula into the Arabian Sea was still active. This provided the suitable trigger point for weather disturbances in the vicinity to develop as rain-generating systems.

The ongoing interaction of the westerly trough and the northeast monsoon system is expected to continue at least for the next two-three days. Under its influence, an upper air cyclonic circulation now lies centred over Orissa and adjoining areas.

Wednesday's cyclonic circulation over Bay of Bengal off the coast of Andhra Pradesh moved overnight in a northwesterly direction and has since merged with the circulation over Orissa. This is likely to cause fairly widespread to widespread rainfall over the Eastern and Northeastern States and scattered to fairly widespread rains in the remaining areas of south peninsular India, the Lakshadweep and Andaman & Nicobar Islands.

During the 24 hours ended Thursday morning, most parts of Tamil Nadu, Andhra Pradesh, south interior Karnataka, Orissa, Lakshadweep, Jharkhand, Gangetic West Bengal and the Northeastern States received light to moderate rainfall.

Parts of Konkan, Goa, east Uttar Pradesh, east Madhya Pradesh, Chhattisgarh, Bihar, Andaman and Nicobar, Kerala, Uttaranchal and Himachal Pradesh received scattered rain.

Excess for Andhra: Rainfall statistics show that all three meteorological subdivisions in Andhra Pradesh received excess rainfall during the northeast monsoon. Entire Coastal Andhra Pradesh (nine districts) and Rayalaseema (four districts) returned excess figures while Telengana lost the record narrowly.

But Telengana topped in individual records with Karimnagar (+315 per cent), Adilabad (+237 per cent), Mehabubnagar (+150 per cent) and Medak (+144 per cent) topping the charts for the entire State.

More than half of the districts in the met subdivision of Tamil Nadu and Pondicherry had excess rain records, with Coimbatore topping with +259 per cent. Sivaganga (+114 per cent), Virudhunagar (+100 per cent), Chennai (+82 per cent) and Pondicherry (+60 per cent) were the other significant rainfall figures in the subdivision.

The districts of Cuddalore (scanty, -64 per cent) and Villupuram (-54 per cent, deficient) and Vellore (-46 per cent, deficient) stood out with poor rainfall records for the season till date. Seven other districts recorded normal rainfall.