Monsoon has arrived on time and rains in the June-September period would be above normal in most parts of the country, says US-based International Research Institute for Climate Prediction (IRI). ‘‘This tendency for above normal monsoon rainfall is related to expected conditions in the tropical Pacific during June-September period. There is a 60-per cent probability for a La Nina during that time and La Nina is historically associated with a tendency for India to receive above normal rainfall,’’ says IRI. (La Nina is the cooling down of Pacific waters below a normal point). IRI has said that its monsoon rainfall outlook for India is based primarily on historical data and also on predictions made by several dynamical models which agreed with a general tendency for above normal rainfall over most parts of the country. ‘‘Conditions in mid-May have suggested early stages of La Nina and these Pacific conditions were not obvious in March or April. While the predictions made during January through March often are low in accuracy, those from late April and May become more accurate and so there is a growing confidence that a La Nina will be in effect by June 2003.’’ According to IRI, India’s worst drought in 2002 was due to the presence of El Nino — the warm episode in the Pacific. The IRI forecast has said there would be heavy rains over Gujarat, Konkan and Goa, central Maharashtra, Jammu and Kashmir, major parts of Rajasthan, parts of west Madhya Pradesh and western parts of north interior Karnataka.
