Date:29/08/2006 URL: http://www.thehindubusinessline.com/2006/08/29/stories/2006082903210800.htm

Back Rains may return to central, western India

Vinson Kurian

Thiruvananthapuram , Aug. 28

The rains are threatening to come back with a vengeance to Central and West India with the latest `low' in the Bay of Bengal showing signs of intensifying, and, most importantly, beginning to deviate from the forecast path.

The system was earlier thought to `lock' itself into the eastward-bound upper air westerly trough and proceed to liven up the ongoing and badly needed wet session in the east and northeast of the country.

SYSTEM DE-LINKS

Passing westerly troughs triggering the formation of a `low' in the Bay and driving it to the east of the country is a normal occurrence during the weakening phase of the monsoon. But this is not what is turning out to be in the instant case, said Dr K.J. Ramesh of the Department of Science and Technology.

The `low' has gone on to become `well marked' and is seen intensifying rapidly into a possible depression. Significantly, it has managed to de-link itself from the dominant westerly trough and has cut loose to take a north-westerly course.

FAMILIAR TRACK

This is now feared to take the system along a familiar track that would bring parts of Central and North Peninsular India, which underwent successive rounds of flooding over the past few weeks, right under its nose, said Dr Ramesh.

The monsoon trough still has its western end nestling more or less in the Himalayan foothills, which normally indicates the weak phase of the monsoon. But it has got a tail wagging in the east, dipping right into centre of the `low' in the Bay. This is what seems to be driving the renewed monsoon pulse in Central India.

The National Centre for Medium Term Weather Forecasting said in its forecast that the well marked `low' off the north Orissa and West Bengal coast persisted on Monday. Tipped to intensify, the system will bring widespread rainfall with scattered heavy to very heavy falls over Orissa during next 48 hours.

INTERACTION LIKELY

Isolated heavy to very heavy falls are also likely over Sikkim, Bihar, East Uttar Pradesh and North Coastal Andhra Pradesh during the next three to four days. The rains are expected to extend towards Gangetic West Bengal, Jharkhand, Bihar, East Uttar Pradesh, Chhattisgarh and East Madhya Pradesh.

Model predictions suggest that another western disturbance is likely to affect the hilly regions of Northwest India on Wednesday and Thursday. This raises the possibility of interaction of the `low' (which the prevailing Bay system is expected to weaken prospectively into) with the incoming westerly system over the central parts of the country, promising more rain.