India Meteorological Department (IMD) in its first stage operational forecast for the southwest monsoon seasonal (June to September) rainfall for the country as a whole has forecasted the monsoon seasonal rainfall to be 97% of the Long Period Average (LPA) with a model error of ± 5%.

The LPA of the season rainfall over the country as a whole for the period 1951-2000 is 89 cm. Forecast also suggests maximum probability for normal monsoon rainfall (96-104% of LPA) and low probability for deficient rainfall during the season.

IMD will issue the update in early June, 2018 as a part of the second stage forecast. 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.

The 5 category probability forecasts for the Seasonal (June to September) rainfall over the country as a whole suggest probability of rainfall to be deficient i.e. below 90% of LPA is only 14% and below normal (90-96%) is 30%. However, the probability of rainfall to be normal (96-104%) is 42%, above normal (104-110) 12% and excess (>110) is 2%.