Date:06/11/2008 URL: http://www.thehindubusinessline.com/2008/11/06/stories/2008110650611900.htm

Back Sulking easterlies extend cold snap in South

Vinson Kurian

Thiruvananthapuram, Nov. 5 The near total absence of easterly to northeasterly winds continued to provide the perfect ruse for colder westerlies from northwest India to fan out into the peninsula along the southern flank of a seasonal anti-cyclone.

Minimum temperatures were largely below normal at one or two places over north interior Karnataka and Rayalaseema, the Chennai Met Centre said.

But day and night temperatures continued to be above normal over large parts of north, central and west India, having warmed up after the tail of a western disturbance passed by the region a few days back.

FRONT PAYLOAD

An incoming western disturbance has a moisture-laden payload in the front that raises humidity levels and associated convective activity leads to precipitation. The rear of the system is marked by cold and sinking air.

India Meteorological Department (IMD) said in its update on Wednesday that a feeble western disturbance lay in wait over Afghanistan and adjoining north Pakistan.

It is tipped to move east into India and trigger light precipitation or snow over Jammu and Kashmir during the next two days. The cold air filling the region in its wake could bring down night temperatures over northwest India appreciably.

On Wednesday, a trough in the lower-level easterlies from southwest to west-central Bay of Bengal persisted (this marked the maximum extent to which easterlies were able to penetrate).

Meanwhile, the seawaters on both sides of the peninsula have warmed up northward from the Equator in anticipation of a weather-making system.

LIKELY ‘LOW’

In fact, the European Centre for Medium-Range Weather Forecasting persisted with its outlook for a low-pressure area to spin up around the South Andaman Sea around November 13.

The system is seen getting a move to the west-northwest, intensifying in the process, before aiming to wash ashore over the Tamil Nadu-Andhra Pradesh coast two days hence.

The US-based Centre for Ocean-Land-Atmosphere Studies (COLA) sees most of the southern peninsula being brought under a hesitant but growingly assertive wet cover by the end of this week (ending November 12).

The week that follows would see a much more organised regime of rainfall venture into the Tamil Nadu coast, before pushing further west into adjoining Kerala and Karnataka.