Date:08/12/2006 URL: http://www.thehindubusinessline.com/2006/12/08/stories/2006120802211200.htm

Back `Strong easterly wave' over Andaman Sea

Vinson Kurian

Thiruvananthapuram , Dec. 7

The migrant remnant from tropical storm Durian (24W) has set up a base over Andaman Sea as a "strong easterly wave," says the National Centre for Medium range Weather Forecasting (NCMRWF).

It is set to revive the northeast monsoon over south coastal Tamil Nadu and Kerala, which would start receiving widespread rainfall from Sunday onwards.

The US Navy's Fleet Numerical Meteorology and Oceanography Centre (FNMOC) also located the system over the Andaman Sea at 11.30 a.m. on Thursday with an estimated central pressure of 1004 millibars.

According to Mr Jim Andrews of AccuWeather.com, 24W is consolidating, after having crossed the Malay Peninsula.

"There is some potential for it to regain tropical storm status before reaching the southeast coast of India on or about Sunday."

Even without this strengthening, 24W will be enough, on its own, to return rain to peninsular India, he added.

Mr J.V. Singh of NCMRWF said incoming western disturbances, if not spaced out comfortably between themselves, do not allow cold air to settle in over the plains. The arrival phase raises temperatures thanks to convective activity in front of the western disturbance.

But the rear of the system is marked by `subsidence,' and lets in cold air in its wake, which will bring down mercury levels.

A second system arriving close on the heels will not allow this to happen and will in fact bring its own convective head to the front, warming the air.

Temperatures are now expected to fall significantly after December 12 only, bringing them to either normal or near normal.

SNOWFALL

Meanwhile, in the north, model predictions suggest that the ongoing snowfall/rains are likely to further reduce, with the western disturbance moving away in an eastward direction.

Another western disturbance is likely to approach Jammu and Kashmir and the adjoining hilly region on Sunday/Monday. Under its influence, the hilly regions of northwest India may experience scattered to fairly widespread snowfall/rains.

MERCURY LEVELS

Plains in Punjab, Haryana (including Delhi) and west Uttar Pradesh may receive isolated light showers around during this time. But, night temperatures are not seen falling to the levels that aid the prospects of the rabi wheat.

A fog alert is in place during morning and evening hours for parts of Punjab, Haryana and West Uttar Pradesh during the next two days.