The Hindu Business Line : `Low' materialises, intensifying rapidly

The first pre-monsoon `low', predicted almost a week in advance by the National Centre for Medium range Weather Forecasting (NCMRWF), has materialised over the Southeast Bay of Bengal.

The system is intensifying rapidly and is set to concentrate into a depression by Monday evening itself, said Dr Akhilesh Gupta, Director, NCMRWF.

It was located over Southeast Bay and adjoining South Andaman Sea (at 8.1N and 91.5E, along the Nagercoil latitude, to the southwest of Nicobar Islands).

Speaking to Business Line, Dr Gupta said the `low' had taken shape late by Sunday evening.

The system packed winds clocking 27 km per hour on Monday afternoon.

It is seen as moving initially in a north-northwest direction for the first two days.

It will later encounter mid-latitude westerlies, lose its top under the `shear effect' and will be forced into taking a northeastward course.

The Indian coast is likely to be spared from its destructive impact.

In its outlook, the Joint Typhoon Warning Centre (JTWC) has upgraded to `fair' the probability of the system developing into a significant tropical cyclone. The European Centre for Medium-Range Weather Forecasting (ECMWF) maintained the outlook that the cyclone could go on to hit the Myanmar-Bangladesh coast by Saturday. According to Dr Gupta, the onward course of the system will be matched only by a corresponding increase in temperatures over land.

The pre-monsoon heating is already on as predicted, and the landmass will continue to be wiped clean of moisture thanks to the drag effect of the low/depression.

This will intensify the heating over a period of the next four to five days. But Dr Gupta ruled out any chance of a severe heat wave, as was the case last year, which was caused due to the delayed arrival of southwest monsoon.

The ongoing heating phase could be a transient phase at best, and the first prospective western disturbance passing in from the country's northwest could cut it short.

But no such system was on the weatherman's radar for the next four-five days.

In its update on Monday, the NCMRWF said day temperatures were above 40°C over parts of Rajasthan, Madhya Pradesh, Chhattisgarh and Maharashtra (above normal by 1-2 deg C).

Predictions continue to suggest gradual rise in day temperatures over North, Central and North Peninsular India during the next four to five days.