La Niña conditions are likely to develop during the second half of the monsoon season.
New Delhi, India is likely to witness above-normal rainfall in the four-month monsoon season (June to September) with cumulative rainfall estimated at 106 percent of the long-period average (LPA) as per the Meteorological Department (IMD).
The LPA of the season’s rainfall over the country as a whole for the period 1971-2020 is 87 cm.
Issuing the Long Range Forecast (LRF) for 2024 Southwest Monsoon Season Rainfall, the Weather agency said currently, moderate El Niño conditions are prevailing over the equatorial Pacific region which will likely weaken further to neutral El Nino Southern Oscillation (ENSO) conditions during the early part of the monsoon season.
The IMD said La Niña conditions are likely to develop during the second half of the monsoon season.
“La Nina conditions, associated with good Monsoon in India, are likely to be set in by August-September, said IMD. Data from 1951 to 2023 shows India experienced above-normal monsoon rainfall on 9 occasions when La Nina followed the El Nino event” said IMD Director General Mrutyunjay Mohapatra.
“Positive Indian Ocean Dipole conditions are predicted during the monsoon season. Also, the snow cover in the Northern Hemisphere is low. These conditions are favourable for the Indian southwest monsoon” he said.
At present, neutral Indian Ocean Dipole (IOD) conditions are prevailing over the Indian Ocean and the latest Climate model forecasts indicate that the positive IOD conditions are likely to develop during the later part of the southwest monsoon season.
As per IMD, the northern hemisphere snow cover extent during the last three months (January to March, 2024) was below normal.
Winter and spring snow cover extent over the Northern Hemisphere as well as Eurasia has a generally inverse relationship with the subsequent Indian summer monsoon rainfall.
India received “below-average” cumulative rainfall — 820 mm compared to the long-period average of 868.6 mm — in 2023, an El Nino year. Before 2023, India recorded “normal” and “above-normal” rainfall in the monsoon season for four years in a row.
