The Hindu Business Line : Easterlies beckon even as hold-up continues

Thiruvananthapuram, Oct. 18 Hold-up in the withdrawal of southwest monsoon continued for a third day even as wind flow charts gave out signals that easterlies may slightly gain in speed over extreme southeast Bay of Bengal from Friday.

Satellite pictures showed clouds massing around the south Andaman Sea, which could be fronting up for an easterly wave. Tamil Nadu and Kerala are the two States where an “easterly wave” will have any direct impact at all.

The wave has a wobbly motion about it that places it alternatively to the front or back relative to its centre even as the whole system registers a net forward movement to the west. An important feature about the system is that it creates some weather only in front, while the air will be absolutely clear in the rear.

This goes to ensure that the worst impact of the weather thus created will also not last longer than 24 hours. But the intensity could be at times so high as to create cloudburst-like conditions. Easterly waves have in the past grown to set up even cyclones. An easterly wave could well be the trigger that the northeast monsoon needs to launch itself.

Satellite pictures on Thursday revealed a grouping of cyclonic circulations lingering in the extreme south peninsula. Together with the “rogue” circulation in the northeast, which has on Thursday become less marked, it will continue to empty moisture for yet another day.

An India Meteorological Department (IMD) update said that rain or thundershowers are likely at a few places over Andaman and Nicobar Islands, coastal Andhra Pradesh, Tamil Nadu, Kerala, Lakshadweep, coastal Karnataka and south interior Karnataka.

These areas constitute the typical east to west geography that the northeast monsoon is known to play around in. The east-west shear zone provides the playground but the north easterlies are refusing to play ball, having been short-changed by the cyclonic circulations.

Rain forecast in South

In the south, the systems are present over southeast and east-central Arabian Sea off the Karnataka and Kerala coasts while the counterpart system is over Kanyakumari and the neighbourhood. Heavy rain has been forecast for isolated places in both Tamil Nadu and Kerala for the next two days.

In the north, remnants of a trough in the westerlies travelling east over north India will also spill some of their contents in the hilly regions of the north.