Monsoon may start 7-10 days early - expert

"This year the monsoon may hit the Kerala coast a week to ten days ahead of schedule," said P.V. Joseph, a former director at the India Meteorological Department and professor emeritus, department of atmospheric science, at the Cochin University of Science and Technology.

Joseph said the forecast was based on a phenomenon known as "pre-monsoon rain peak" in which the temperature of the Bay of Bengal off the east coast of the subcontinent rises about 40 days before the monsoon and clouds near the equator move north to bring rains on the southern tip of India.

When monsoon rains are delayed, this phenomenon occurs in early May, but this year it was observed in the first half of April, signalling early arrival of rains, he said.

"It is an indicator of coming monsoons. In most of the years, it has come true," said Joseph, who is often consulted by the government's weather office and invited to lecture on monsoon trends by the ministry of earth sciences which funds weather research.

"Last year the pre-monsoon rain peak took place in April and the monsoon arrived earlier," said Joseph, a resident of Cochin, now widely called Kochi, a city in the southwest Indian state of Kerala which hosts a key weather station for monsoon observance.

A senior weather scientist at a government body agreed there is a correlation between the "pre-monsoon rain peak" and the onset of the monsoon, but there may be a gap of up to four days between the forecast based on this phenomenon and the start of rains.

If rains begin before the usual date, it helps early sowing and harvesting of crops such as rice, soybean, and corn and shields them from any dry spell towards the end of the season.

The Indian monsoon, forecast to be normal this year, is keenly watched by traders and analysts as the country, one of the world's top producers and consumers of sugar, wheat, rice and edible oils, counts on rains to irrigate 60 percent of its farms.
The four-month monsoon season usually begins on June 1 with the first showers in Kerala and covers the rest of India and neighbouring countries by July.

Last year, the June-September season, which delivers 75-90 percent of the total rainfall in most parts of India, was the worst since 1972, stoking inflation and making India the world's top buyer of edible oils and a big sugar importer.

But the 2009 season began on a promising note with heavy showers from May 23 as monsoon rains arrived ahead of schedule.