India Meteorological Department (IMD) has published seasonal forecasts of rainfall for the southwest monsoon season (June to September). Operational forecast of summer monsoon has done on two stages. The first stage forecast is issued in April and second one issued on June. These forecasts are prepared using state of-the-art Statistical Ensemble Forecasting system (SEFS) that is critically reviewed and improved regularly through in-house research activities.

The weak La Nina conditions developed in the later part of the last monsoon season peaked in December 2016 and started weakening thereafter. Currently, neutral conditions are prevailing over the equatorial Pacific. The atmospheric conditions over the Pacific also reflect neutral El Nino conditions. The latest forecast from MMCFS indicates weak El Nino conditions to develop during the latter part of the monsoon season.

The forecast suggests that the monsoon rainfall during the 2017 monsoon season (June to September) averaged over the country as a whole is likely to be 96% ± 5%of the Long Period Average (LPA).

  1. Quantitatively, the monsoon seasonal rainfall is likely to be 96% of the Long Period Average (LPA) with an error of ± 5%.
  2. Forecast assessment suggests 38% of probability for near normal monsoon rainfall