IMD Forecast Signals Cooler Summer, Rising Thunderstorm Activity, and Looming El Niño Risk Across India

While the milder weather should provide some respite to customers, and also lower power demand in the midst of an energy crisis brought about by the war in West Asia, a wet April co damage standing ready-for-harvest crops, some of which have already been impacted by western disturbances in the second half of March.

In what could further impact the farm sector, the agency predicted an 80% likelihood of an El Nino developing in the second half on monsoon which could sap the rainy season.

In its forecast, IMD said many parts of eastern and the North East, and also the eastern parts Central India, and the peninsular region adjoining these could, however, see hotter days. Below normal day temperatures and high night temperatures are expected mainly due to likely higher rainfall, thunderstorm activity and cloudy nights and days. Cloud cover makes nights warmer by trapping heat radiating from the Earth's surface. The weather office has predicted above normal rain, at 112% of the long period average, in April; the LPA, based on average rain from 1971-2020 is 39.2 mm.

"Intense and widespread thunderstorm activity is likely in different parts of April. People should be cautious especially those working outdoors. Three western disturbances are expected to impact until April 9 and they will travel eastwards causing thunderstorm activity. There are easterly waves over peninsular region also which cause thunderstorm activity," said M Mohapatra, director general, IMD. "This updated forecast is not completely different from the one we issued in March but now we can say more heat wave days are likely in May and June compared to April," Mohapatra added. During April, above-normal heatwave days are likely over many parts of coastal areas of Odisha, West Bengal, Tamil Nadu, Puducherry and Andhra Pradesh and isolated regions of Gujarat, Maharashtra and Karnataka, IMD said.

At present, neutral El Niño-Southern Oscillation (ENSO) conditions are prevailing over the equatorial Pacific Ocean, IMD said. The latest forecasts from the Monsoon Mission Climate Forecast System (MMCFS) suggest that ENSO-neutral conditions are most likely to continue till June. Thereafter, the probability of development of El Niño conditions increases gradually. There is a 62% chance of El Nino emerging in June-July-August period and there is an 80% chance of El Nino persisting in August-September-October.

El Niño years typically bring weak monsoons and harsh summers to India. The monsoon is primarily driven by the intense heating of land compared to the sea during summer.

When asked whether normal to below normal temperatures this summer will impact the monsoon, Mohapatra said factors other than land heating also have an important role to play. IMD will issue the initial monsoon forecast around mid April, he added. Currently, neutral Indian Ocean Dipole (IOD) conditions are prevailing over the Indian Ocean. The latest MMCFS forecast suggests that these neutral IOD conditions are likely to persist during the April to June season and thereafter. For east and northeast India, IMD has warned of significant heat stress.

The evolving weather pattern, marked by cooler days, elevated thunderstorm risks, and a high probability of El Niño, underscores a complex and potentially disruptive season for agriculture, energy demand, and overall climate stability across India.