Southwest monsoon withdraws entirely

It bid adieu over a week later than normal.

The southwest monsoon, which had begun withdrawing from September 25, today receded from all over the Indian mainland, giving way to the arrival of the northeast monsoon in the southern peninsula.

The total rainfall in the extended part of the monsoon season since October 1 has been 44 per cent above normal. It was deficient by 23 per cent in the main southwest monsoon season between June 1 and September 30.

Normally, the southwest monsoon withdraws from the entire mainland by mid-October. This year, it bid adieu over a week later than normal.

The beginning of the withdrawal phase of the monsoon, too, was behind schedule, by some 25 days. It had begun receding from West Rajasthan on September 25, instead of the normal date of September 1.

The southwest monsoon season accounts for over 80 per cent of the country’s total annual rainfall.

Announcing the monsoon withdrawal, the India Meteorological Department (IMD) today said southwesterly winds have been replaced by northeasterly winds in the south peninsula. The entire country is likely to remain dry for the next four to five days, except Jammu and Kashmir and the southern peninsula, where isolated showers are expected.

The total rainfall during the 2009 monsoon season (June–September) was 77 per cent of the long period average rainfall of 89 cm. Month-wise, the rainfall was 53 per cent of the normal in June, 96 per cent in July, 73 per cent in August and 79 per cent in September.

The post-monsoon rainfall in October has so far been above normal, thanks to the belated withdrawal of the southwest monsoon. IMD data indicates total rainfall between October 1 and 21 was 67.6 mm, about 44 per cent above the normal rainfall of 47 mm for this period.

In all, 24 of the country’s total of 36 meteorological subdivisions have received normal or above normal rainfall in the post-monsoon period. These subdivisions span 64 per cent of the country’s area.