
The states with coastlines along the Bay of Bengal have been anxiously watching the unfolding of the giant movements of wind, sea moisture and pressure which is now called Cyclone Amphan.
Once that cyclonic threat has played itself out – and until it does Odisha, West Bengal and Assam will be on high alert – the countdown to normal rains will resume.
On 15 April, the India Meteorological Department (IMD) issued its customary first phase long range forecast for the south-west monsoon. And the primary take-away was: “South-west monsoon seasonal (June to September) rainfall over the country as a whole is likely to be normal (96-104%).”

Quantitatively, said the IMD, the monsoon seasonal (June to September) rainfall is likely to be 100% 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 1961-2010 is 88cm.
IMD’s forecast based on the Monsoon Mission Coupled Forecasting System (MMCFS) uses atmospheric and oceanic initial conditions during March 2020. The forecast was computed as the average of 51 ensemble members. The forecast based on the MMCFS suggests that there is a high probability (70%) for 2020 monsoon rainfall to be above normal to excess (more than 104% of LPA).