Rain or thundershowers are expected to lash isolated places over interior Karnataka and Kerala on Wednesday and increase, thereafter, as the southern peninsula awaits the North-East Monsoon.

Wind pattern

The India Meteorological Department has said that thundershowers may continue to persist into the weekend and early next at many places over the southern peninsula and Andaman and Nicobar Islands.

This phase would also witness the change of wind flow to being easterly (from the East).

Given this, the North-East Monsoon could set in around October 20.

Rain pulse

Meanwhile, on Tuesday, South China Sea typhoon ‘Nari’ made a landfall over the Vietnamese coast. It is likely to push in a ‘rain pulse’ across Myanmar into the Bay of Bengal. Associated circulation is forecast to wash ashore over Gangetic West Bengal coast, and it would have signalled the arrival of the North-East Monsoon.

MUTED START

But even before this, a helpful trough (where wind flows converge) would form along the Tamil Nadu coast and bring in some rain into the hinterland, which is exactly what the IMD has forecast on Tuesday. Rains heralding the North-East monsoon may not be spectacular to start with, and are likely stay that way until October 25. This is because yet another strong typhoon (regional name for cyclone) is forecast to develop over the Central Pacific.

more to follow

Unlike typhoon ‘Nari,’ the freshly brewing storm is seen moving away east-north-east and further out into the Pacific. While doing so, it would take away some of the moisture that would have been directed into the north-easterly flows over southern peninsula.

BAY PULVERISED

The Bay of Bengal basin has been pulverised by the heavy to very heavy rain from erstwhile very severe cyclone Phailin, causing the seawaters to ‘cool down’ by several notches.

It would take a few more days before the ocean heats up again and rebuilds the energy required to host another significant weather system.

>vinson.kurian@thehindu.co.in

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