1.1.1 Indian Meteorological Department

The report on the long-range forecast (LRF) for monsoons by IMD published on 15th April 2020 expects monsoon rainfall to be normal this year. Also, the monsoon seasonal rainfall is likely to be 100% of the Long Period Average (LPA) with a model error of +/- 5% (Forecasting of IMD during 2018 monsoon was 97% and for 2019 was 96%). Currently, neutral El Nino South Oscillation (ENSO) conditions are prevailing over the Pacific Ocean and the Neutral Indian Ocean Dipole (IOD) conditions are prevailing over the Indian oceans are the two important factors influencing Southwest monsoon. In the subsequent monsoon season, several model predictions suggest that these conditions are likely to continue. Some other global climate models, however suggest that poor La Nina conditions can evolve in the Pacific Ocean in the second half of the season. The statistical model suggests a probability of 21% for 2020 monsoon rainfall to be above normal rainfall (104-110 of LPA) and only 9% for excess rainfall (>110 of LPA). IMD will issue its second long-range forecast either in the last week of May or the 1st week of June which also includes different zonal predictions. Based on this zonal prediction we will a clear picture of rainfall in South India including Kerala. All the forecasting by IMD is based on the precipitation from June to September during Southwest Monsoon. The rainfall during the June – September monsoon season is likely to be in line with the long term average of 880. From the above statistics we cannot predict the extent of precipitation whole over the country or the severity of southwest monsoon. These details are available from the prediction of IMD on 5days rainfall report on the district level basis

The long-range forecast (LRF) for the monsoon by IMD can be seen here:

https://mausam.imd.gov.in/Forecast/marquee_data/1st_Stage_LRF_apr_2020_English.pdf

The available international, private agencies which are working on LRF for monsoon 2020 are included in Annexure.