Small dip likely in south-west monsoon this year

Meteorological department to issue forecast on Tuesday

While monsoon may be normal in most parts of South Asia, it would fall short of the average level in the grain basket of Punjab and Haryana and rice cultivation areas in east and central India and Bangladesh, says an outlook of the monsoon season.

In the western region including Punjab and Haryana as well as in Gangetic West Bengal, there is 75-80 per cent possibility of the monsoon remaining within normal to below normal range. The same trend is expected in central India as well.

The outlook indicates slightly enhanced likelihood for below normal rainfall conditions over the north-western and north-eastern parts of South Asia.

Above normal monsoon with bountiful rainfall was likely only the in southern peninsula and islands, says the consensus statement on monsoon outlook released by the Indian meteorological department (IMD), Pune, after a meeting of the South Asian Climate Outlook Forum between April 13 and 15.

The consensus outlook, however, is not the operational monsoon forecast that will be issued by the IMD on Tuesday. It was made by a group of scientists based on their analysis of previous trends taking into account various empirical and dynamic models and prevailing global conditions.

Cautionary warning

The outlook gives cautionary warning on a possible decrease in the second half of the season due to a negative Indian Ocean Dipole (IOD) – a temperature seesaw in the Indian Ocean. Since negative IOD weakens the monsoon, there is a possibility of rainfall deficiency.

El Nino – the sea surface temperature anomaly in the Pacific that plays havoc with weather systems throughout the world – does not seem to be have much influence on the southwest monsoon this time around.

Last year was a normal monsoon year in which the overall rainfall was 102 per cent of the long period average of 89 cm. Maximum rainfall was witnessed in northwestern and southern India despite not having a single monsoon depression in the Bay of Bengal.

“Going by the consensus outlook, it’s possible that June-July will have normal rain and deficiency could occur in August-September. But it’s too early and more clarity would come next month. The IMD, however, has to monitor the IOD closely,” a monsoon forecaster told Deccan Herald.