The southwest monsoon is likely to hit the Kerala coast around June 1, well within its normal date of arrival, the India Meteorological Department (IMD) said on Tuesday.
“The date of onset of the southwest monsoon over Kerala is likely to be June 1, with a model error of +/- four days,” the met office said in a statement.
The southwest monsoon, which is crucial not only for agriculture, but also for the general economic growth, would advance over the Arabian Sea around May 20, the met office said. The monsoon’s advance over Andaman Sea is expected to be slightly later than its normal date, but well within the standard deviation, it added.
The southwest monsoon enters the Indian mainland through the Kerala coast in June and then covers the entire country in the subsequent months. It starts retreating from west Rajasthan around September, after completing its four-month journey over India.
The four-month monsoon provides about 70 per cent of the total annual moisture India receives. The IMD had, in its first official forecast for the 2012 southwest monsoon released last month, said rains during the four- month monsoon season would be, by and large, normal across the country. However, the met office did not entirely discount the impact of El Nino, which causes less rains during the second half of the season.
“Rains this year would be around 99 per cent of the long period average (LPA). Normal monsoon is considered in case rains are between 96 to 104 per cent of LPA,”the IMD said. The LPA is the average rainfall across the country in 50 years, starting 1941. It is estimated at 89 centimetres.
There is a 47 per cent chance of the monsoon being normal this year, and a 24 per cent chance of it being below normal.
The monsoon has received, added importance this year after some foreign weather forecasters made adverse prediction of rains this year.
The Japan Agency for Marine-Earth Science and Technology and the International Research Institute for Climate and Society at the Columbia University had, in December-January, predicted there was little chance of India getting above-normal monsoon this year.
This was followed by a forecast by the United Kingdom’s meteorological office, which, in its long-range global weather forecast, said the chance of India getting above-normal rainfall during the four-month period of July-September was only 40 per cent.
