Monsoon may start withdrawing from North-West India from Tuesday

With the four-month-long monsoon entering the last month of September on Tuesday, the rain deficit for the country as a whole is likely to grow beyond the 12 per cent forecast by the India Met Department.

The 12 per cent-mark was reached by end-August though it has been set back by one percentage point to 11 per cent on Monday, last day of the month.

What has apparently helped the overnight reduction in deficit is the heavy to very heavy rain over East and North-East India where the deficit has come down to two per cent.

But it has worsened to 21 per cent in South Peninsula; 15 per cent in Central India; and 10 per cent in North-West India. These three constitute the farming heartland of the country.

Model analyses suggest that the monsoon may start to withdraw from extreme northwest (Rajasthan) on Tuesday to signal the start of the month-long process. Rains have kept away from most of Rajasthan and neighbourhood for more than a week now.

The withdrawal takes place in an elaborate swipe of the air in the Northeast-East-Southeast-South-Southwest (clock-wise) direction when monsoonal rain evaporates from the surface covered. By the second week of September, it would cover North and North-West India and parts of adjoining Central India, says an assessment of the Indian Institute of Tropical Meteorology.

It is also likely that part of the North, including Jammu and Kashmir, would witness showers from western disturbance activity – and not monsoonal.

The assessment also gives out clear indications that rainfall until mid-September would be below normal except over parts of East and North-East India. This would worsen the drought-like conditions being witnessed over many parts of the country. Statisticians merely want to know by what margin the 12-per cent mark for deficit would be beaten.

The US Centre for Climate Prediction sees the north of the country drying up fast during the first two weeks of September. But occasional showers would help cool things over the southern parts during this period.

It sees normal to above normal rain for the South-East (coastal Tamil Nadu and Andhra Pradesh) of the country. The rest of the peninsula may also benefit from passing showers.

A short-to-medium term forecast put out by the Indian Institute of Tropical Meteorology suggests the following:

August 30 to September 3: Rain for East and North-East.

September 4 to 8: Rain for South India.