India will have a normal Southwest Monsoon, the lifeline of the agrarian economy of the country, this year, according to the India Meteorological Department (IMD).
“Southwest monsoon seasonal (June to September) rainfall over the country as a whole is likely to be normal (96-104%),” the IMD said in its first stage Long Range Forecast (LRF) for monsoons.
Addressing a press conference, Secretary of Ministry of Earth Sciences Dr. M. Rajeevan released the IMD’s Long Range Forecast for the 2021 Southwest Monsoon Season Rainfall. Director General of IMD, Dr. M. Mohapatra was also present.
Dr. Rajeevan said that quantitatively, the monsoon seasonal (June to September) rainfall is likely to be 98 % of the Long Period Average (LPA) with a model error of 5%.
Dr. Rajeevan pointed out that Neutral El Nino Southern Oscillation (ENSO) conditions are prevailing over the Pacific Ocean and Neutral Indian Ocean Dipole (IOD) conditions are prevailing 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 added.
Dr. Rajeevan said that La Niña conditions are likely to prevail only till May so we will transition to ENSO (El Nino and Southern Oscillation) neutral conditions during monsoon. There is very little chance of El Niño conditions developing during monsoon months. There is a very small probability of Indian Ocean Dipole (IOD) negative condition developing during monsoon. So these conditions are likely to lead to a normal monsoon this year, he explained.
Director General of IMD, Dr. M. Mohapatra explained that IOD is characterised by warmer sea surface temperature in the equatorial Indian Ocean; positive IOD conditions are usually associated with normal or above normal monsoon.
He said, while most of the country will have normal monsoon rains, some parts of east and northeast India including Jharkhand, Odisha, Bihar and the northeastern states are likely to record below normal rains this year according to IMD’s analysis
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.
Summary of the Forecast for the 2021 southwest monsoon Rainfall
a) Southwest seasonal (June to September) rainfall over the country as a whole is most likely to be normal (96 to 104 % of Long Period Average (LPA).
b) Quantitatively, the seasonal (June to September) rainfall is likely to be 98% 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 88 cm.
c) Neutral ENSO conditions are prevailing over the Pacific Ocean and Neutral Indian Ocean Dipole (IOD) conditions are prevailing over the Indian Ocean. The latest global model forecast indicates neutral ENSO conditions are likely to continue over the equatorial Pacific and negative IOD conditions are likely to develop over the
Indian Ocean during the ensuing season.
As sea surface temperature (SST) conditions over the Pacific and the Indian Oceans are known to have strong influence on Indian monsoon, IMD is carefully monitoring the evolution of sea surface conditions over these Ocean basins. IMD will issue the updated forecasts in the last week of May2021. In addition to update for the April forecast, forecasts for monsoon season (June-September) rainfall for four homogenous regions and forecast for the month of June also will be issued.
Last year, the Southwest Monsoon hit Kerala on June One.
