"Southwest monsoon seasonal (June to September) rainfall over the country as a whole is likely to be normal," the IMD said in its first stage Long Range Forecast (LRF) for monsoon.
Secretary of Ministry of Earth Sciences, M Rajeevan, released IMD's forecast for the 2020 Southwest Monsoon rainfall at a press conference through video conferencing.
He said that quantitatively the monsoon seasonal rainfall "is likely to be 100 per cent of the Long Period Average (LPA) with a model error of 5 per cent".
The LPA of the season rainfall over the country as a whole for the period 1961-2010 is 88 cm.
"Good news is that it is estimated that the deficient rainfall will be nine per cent. This forecast is based on the statistical model. It suggests that we will have a normal monsoon", he said.
An official release said that the Indian Meteorological Development (IMD) will issue updated forecasts in the last week of May or first week of June 2020 as part of the second-stage forecast.
Rajeevan said that "neutral El Nino Southern Oscillation (ENSO) conditions" are prevailing over the Pacific Ocean and "neutral Indian Ocean Dipole (IOD) conditions" over the Indian Ocean.
"Some climate model forecasts indicate these conditions are likely to persist during the ensuing monsoon season. As sea surface temperature (SST) conditions over the Pacific and Indian Oceans are known to have strong influence on Indian monsoon, IMD is carefully monitoring the evolution of sea surface conditions over the Pacific and the Indian oceans," he said.
Rajeevan said that La Nina, or cooler-than-usual sea surface temperatures in the east-central Pacific Ocean is typically associated with better monsoon rains and colder winters in India while El Nino is associated with below-normal rainfall in the country.
The southwest monsoon season, that replenishes the country's farm-dependent economy, first hits the southern tip of Kerala usually in the first week of June and retreats from Rajasthan by September.
Monsoon is expected to hit Thiruvananthapuram in Kerala on June 1.
In states such as Maharashtra, Gujarat, Madhya Pradesh, Chhattisgarh, Telangana, Andhra Pradesh, Odisha, Jharkhand, Bihar and parts of Uttar Pradesh, monsoon will be delayed by three to seven days compared to the existing normal dates.
However, over extreme northwest India, the monsoon is expected to arrive a little earlier on July 8 compared to the existing date of July 15. Monsoon is expected to withdraw in south India on October 15.
( With inputs from ANI )