A fortnight and more after very severe cyclone Bulbul, the last of the three powerful storms that stomped the Indian territorial waters in October-November, the buzz seems to be heading back to the region.

India Meteorological Department (IMD) has indicated that a low-pressure area may to form over the South-East Arabian Sea and adjoining Equatorial Indian Ocean (around Sri Lanka and Kanyakumari) by Saturday.

Intensification prospects

International weather models invest the low-pressure area over South-East Arabian Sea with prospects of further intensification, but not quite making the grade as a powerful storm.

However, it would be able to draw in a raft of easterlies from the Bay of Bengal through almost the entire first week of December, with South Tamil Nadu and adjoining Kerala making meaningful gains in terms of rains.

During this period, a storm is forecast to impact the upstream Philippine Islands and a potent remnant enter the South China Sea and heading initially West towards the familiar territory of Vietnam.

Anything that impacts Vietnam would be of relevance to the downstream Bay of Bengal and weather watchers would be eager to discern any sign of further development in the Bay.

The IMD has forecast scattered to fairly widespread rainfall with isolated heavy falls lover Tamil Nadu and Puducherry for three days from Saturday. Isolated to scattered rainfall is likely over Coastal and South Interior Karnataka, Kerala, Lakshadweep and the Andaman and Nicobar Islands.

Western disturbances

The European Centre for Medium-Range Weather Forecasts indicates strong stormy and showery activity over South Tamil Nadu with ferocious winds likely whizzing past the Gulf of Mannar and surfing up the waters.

Meanwhile, the northern half of the country is also witnessing some busy weather with western distances, often well-endowed ones, trooping in and triggering snowfall, thunderstorms, high winds and thundershowers.

The well-endowed ones are those blessed with the required size, scale and intensity to affect not just the hills of North-West India but also the plains as well as adjoining Central India and East India.

Its normal for them to induce the formation of offspring cyclonic circulations just as they prepare to enter North-West India along the familiar Mediterranean-Iran-Iraq-Afghanistan-Pakistan route.

The offspring is borne when a limb of the parent western disturbance digs in lower to scoop moisture from the North Arabian Sea (off Gujarat) and south-westerly winds blow in anti-clockwise direction.

The offspring circulation impacts North-West India much ahead of the parent, which takes its own time to drag in the entire entourage across the rugged terrain of Afghanistan-Pakistan.

Rainfall pattern

The IMD located the western disturbance as a cyclonic circulation over Afghanistan neighbourhood on Tuesday with a trough aloft in mid and upper tropospheric levels.

The induced cyclonic circulation, which had initially lain Pakistan and adjoining West Rajasthan, had now shifted base to West Rajasthan, its favourite haunt over North-West India.

The IMD has also suggested that follow-up western disturbance, but a comparatively feeble system, may affect the hills of North-West India from Saturday.

Isolated rainfall/snowfall is likely over the hills and adjoining plains of North-West India. These rains are vital from the viewpoint of the standing Rabi crop.