‘Normal’ monsoon expected this year: IMD
Private forecaster Skymet Weather on Monday forecast “below normal” rainfall during the monsoon season between June and September, citing a strengthening El Nino phenomenon
“Normal” monsoon rainfall to the tune of 96% of the long-period average or LPA (with a model error of +/-5%) of 86.86 cm was expected this year, state-run India Meteorological Department (IMD) said on Tuesday as it expects the adverse impact of El Nino to be neutralised. LPA is the average rainfall between 1971 and 2020.
Private forecaster Skymet Weather on Monday forecast “below normal” rainfall during the monsoon season between June and September, citing a strengthening El Nino phenomenon.
El Nino involves the unusual warming of waters in the eastern equatorial Pacific, which has a high correlation with warmer summers and weaker monsoon rains in India.
IMD, which follows different categorisations for rainfall in meteorological regions and for all India measurements, said there is a 35% probability of normal and a 29% possibility of below-normal monsoon this year.
El Nino Southern Oscillation (ENSO) neutral conditions prevailed and El Nino was expected to develop in July.
IMD director general M Mohapatra said all El Nino years are not bad monsoon years. There have been 15 El Nino years between 1951 to 2022 and six of them recorded “normal” to “above normal” monsoon rain.
Positive Indian Ocean Dipole (IOD) conditions, which refer to the temperature differential between the western and eastern Indian Oceans, were also expected to develop. A positive IOD has a direct correlation with a good monsoon.
There has also been low snow cover over the northern hemisphere and Eurasia from February to March 2023 which aids the monsoon. IMD is hence expecting the adverse impact of El Nino to be neutralised by these associated factors
Skymet said it is expected to be “below normal” to the tune of 94% (with an error margin of +/-5%) of the LPA for the 4-month period.
The monsoon is critical for a healthy rural economy as 51% of the country’s farmed area, accounting for 40% of production, is rain-fed, according to the agriculture ministry. As much as 47% of the country’s population is dependent on agriculture, one of the mainstays of India’s economy, for livelihood, according to this year’s Economic Survey.
The monsoon, which is especially crucial for summer crops, brings about 70% of India’s annual rainfall. It spurs farm produce and improves rural spending besides impacting inflation, jobs, and industrial demand.
Good farm output keeps food inflation under check and ample harvests raise rural incomes and help inject demand into the economy.
The annual monsoon forecast as such is widely anticipated and both Skymet and IMD issue multiple forecasts.
Skymet’s first monsoon forecasts of monsoon rainfall for the past five years have differed from the actual rainfall by 4-16% of LPA.
The distance from the time for which the forecast is made is part of the reason why early forecasts get it wrong. Small errors in measurements fed into forecast models can become large errors for periods further away from the day on which the model is being run. All forecasts are more accurate closer to the event.
This year, Skymet’s forecast factored in an evolving El Nino condition.