The Hindu Business Line : ‘Low’ crosses border, but not the rains

Thiruvananthapuram, Oct. 9 The well marked ‘low’ over northeast Bay of Bengal, that has been pumping in a torrent in east and northeast India over the past few days, crossed the border on Wednesday and parked itself over Bangladesh.

But this is not expected to make any drastic difference on the ground, since, even from this remote location, the system would be able to kick up copious rainfall in its backyard, which is India’s east and northeast.

WIDESPREAD RAIN

An India Meteorological Department (IMD) update on Wednesday said that the well marked ‘low’ had moved north from north Bay of Bengal and adjoining Bangladesh to lie weakened as a ‘low’ over Bangladesh and neighbourhood. Models predictions suggest that the system is likely to move north-northeastward.

Under its influence, fairly widespread rainfall with isolated heavy to very heavy falls is likely over West Bengal, Sikkim and the North-Eastern States during the next 48 hours. Scattered rain is likely over Jharkhand, Bihar and Orissa during this period.

Meanwhile, the seasonal anti-cyclonic circulation that brings clear weather and cooler nights has made its presence felt over northwest India. It also helps expedite monsoon withdrawal, in turn preparing the ground in the peninsula for the winter monsoon (northeast monsoon or retreating monsoon).

EXPECTANT SOUTH

The anticyclone will have to move further south along a Gujarat-Madhya Pradesh latitude so that associated northeasterly-to-easterlies on its right flank drives up wind speeds of prevailing easterlies to mass up clouds along the southeast coast and dump their moisture.

Model predictions suggest that the anticyclone is likely to cover some more regions of north and central India during the next five days. With this, the monsoon is expected to withdraw further, bringing dry weather to more parts of northwest and central India.

But things are different in the South, with a cyclonic circulation sitting over east-central and adjoining southeast Arabian Sea off the Karnataka-Kerala coast promising scattered rain along the west coast. A counterpart circulation, an upshot of typhoon-turned-tropical storm Krosa in the east China Sea, is projected to occupy the skies over the Tamil Nadu coast over the next few days.

The ensuing scattered wet conditions could hold good to beyond October 20, which has led weathermen to surmise that the setting-in of the northeast monsoon could take place side by side with the withdrawal of the southwest monsoon from the peninsula.