Vinson Kurian
Thiruvananthapuram, March 9 The Regional Meteorological Centre, Chennai, has forecast isolated rain or thundershowers over coastal Tamil Nadu and Puducherry during the next 24 hours as a wave of summer showers pushes its way into the south peninsula.
The isolated to scattered showers would continue towards the weekend, the regional forecasting agency said in its outlook on Sunday.
The Climate Prediction Centre (CPC) of the US National Weather Services, too, is of the view that the emerging wet weather could last for almost a week until Saturday next (March 14).
Moisture being transported from the Bay of Bengal and adjoining East Indian Ocean is shown to linger over extreme south peninsula farther until Friday, March 20, according to initial conditions, the CPC said on Sunday.
This could trigger passing showers in the region.
TROUGH SHIFTS India Meteorological Department (IMD) said in its update on Sunday that the trough of low pressure over southwest and adjoining southeast Bay of Bengal had shifted to over southwest Bay of Bengal and neighbourhood, closer to Sri Lanka and the peninsular India coast. A cyclonic circulation has surfaced over south Tamil Nadu and adjoining Kerala.
This could be the system spearheading weather over Sri Lanka and the Tamil Nadu coast initially, before guiding it over to adjoining Kerala.
An IMD forecast said that rain or thundershowers are likely at isolated places over south coastal Andhra Pradesh, south Kerala and interior Tamil Nadu from Monday onwards.
On Saturday, the maximum temperature had fallen markedly at one or two places over south coastal Tamil Nadu, at many places over south coastal Andhra Pradesh, and at a few places over north Tamil Nadu.
This is being attributed to the cloud cover thrown up by the trough in the Bay and the cyclonic circulation.
MERCURY DOWN In the north, the maximum temperatures had come down from the summits scaled earlier last week and were above normal by a much reduced margin of 3-6 deg Celsius over northwest, central and adjoining east India. The minimum was above normal by 2-3 deg Celsius over parts of Rajasthan, Gujarat, Orissa and Chhattisgarh.
Current meteorological analysis suggested that a fall in temperatures by 1-2 deg Celsius is likely over northwest, west and central India over the next two days in the wake of the passing of a western disturbance. This is because the rear of the system makes for clear skies allowing cooler westerlies from across the border to penetrate the region.
FRESH WESTERLY But a fresh western disturbance had parked itself over north Pakistan and adjoining Jammu and Kashmir.
As expected, the system has induced the formation of a trough dipping into north Arabian Sea and peninsular India.
A surprise beneficiary from the band of westerlies fanning moisture inland from the sea would be Madhya Pradesh, which would start receiving isolated rain or thundershowers from Monday/Tuesday.
Rain or snow is likely at a few places over Jammu and Kashmir during the next two days and isolated thereafter.
Rain or thundershowers have also been forecast at isolated places over Himachal Pradesh, Uttarkhand, and further east over Arunachal Pradesh, Assam and Meghalaya.