Monsoon rains, the lifeline of the country's Dollars 2 trillion economy, are expected to be 97 per cent of a long-term average, KJ Ramesh, director general of the Indian Meteorological Department (IMD), said.
Rainfall below 90 per cent of the average is considered deficient, above normal at 105-110 per cent, and excessive above 110 per cent. Along with the updated forecast, separate forecasts for the monthly (July and August) rainfall over the country as a whole and seasonal (June-September) rainfall over the four geographical regions of India will also be issued. Since 2012, IMD is also using the dynamical global climate forecasting system (CFS) model developed under the Monsoon Mission to generate forecasts. The Indian Met Department will also today come out with its first official forecast of this year's monsoon.
According to the weatherman, below 90 per cent rainfall is considered deficient and at 95 per cent it is considered below normal. Unlike the IMD, Skymet had predicted a 100 per cent normal Monsoon, with an error estimate of plus-minus 5 per cent.
However, the monsoon can be affected by the El Niño conditions. The country receives some 70 per cent of its annual rainfall during the four-month Monsoon season. Operational forecasts for the southwest monsoon season rainfall are issued in two stages. A year ago also, there was a normal monsoon forecast by the IMD.
The moderate La Nina conditions developed in the equatorial Pacific during last year started weakening in the early part of this year and now have turned to weak La Nina conditions. The upcoming Kharif season is entirely based on Monsoon rains.