Monsoon to be ‘above normal’, predicts IMD
India is expected to have an “above normal” monsoon season with 106% of the long period average, according to the India Meteorological Department.
India is likely to experience an “above normal” monsoon rainfall between June and September this year, the India Meteorological Department (IMD) said on Monday in its long-range forecast, a year after the country recorded below normal rains in 2023.
Monday’s forecast put the overall volume of rainfall across the country to be at 106% of the long period average (LPA), with an error margin of 5%. The government forecaster added that it will update its prediction in the last week of May, when a better picture is expected to be available of how the precipitation will be spread.
“All conditions are favourable for an above normal monsoon. Both dynamical and statistical models are indicating that monsoon will be good over most parts of the country,” said M Ravichandran, secretary, ministry of earth sciences, attributing the forecast to expected changes in oceanic temperature patterns and the amount of snow cover in the northern hemisphere.
“The expected La Nina, positive IOD and below normal snow cover over northern hemisphere would be favourable for rainfall during southwest monsoon season,” Ravichandran said.
Currently, moderate El Nino conditions are prevailing over the equatorial Pacific region. However, latest climate model forecasts indicate that El Nino is likely to weaken to neutral conditions during the early part of the monsoon season (June-July), and La Nina conditions are likely to develop during the second half of the monsoon season (August-September).
El Nino is characterised by unusual warming of waters in the eastern equatorial Pacific Ocean and correlates with warmer summers, drought, and weaker monsoon rains in India. La Nina has the opposite effect.
El Nino occurs on average every two to seven years, and typically last nine to 12 months.
According to an analysis by IMD, during most of the (22) La Nina years since 1954, monsoon rainfall was normal, above normal, or excess, except in 1974 and 2000 when it was below normal. Based on data from 1951-2023, during the nine La Nina years preceded by El Nino years — a scenario similar to what might happen this year — monsoon was above normal in two years, excess in five years, and on the positive side of normal in two years.
The forecast suggests a 31% probability of an above normal monsoon, 29% probability of a normal monsoon, 30% probability of excess monsoon, 8% probability of below normal monsoon, and only 2% probability of a deficient monsoon.
The spatial distribution suggests above normal seasonal rainfall is very likely over most parts of the country except some areas over northwest, east and northeast India, where below normal rainfall is expected. The models could not give a clear signal for rainfall over parts of central India.
Over the years, the overall monsoon precipitation figures have concealed wide disparities in the rainfall, both in terms of geographic spread and the number of days rains were recorded. Last year, June rains were 9% below average because of the delay in the arrival of rains, but July rains rebounded to 13% above average. August was the driest on record with a 36% deficit, but again in September, rainfall revived and the country received 13% more rainfall than the normal, according to IMD figures last year.
The monsoon delivers nearly 70% of India’s rain and is the lifeblood of its economy. As much as 51% of India’s farmed area accounting for 40% of production is rain-fed and 47% of the population is dependent on agriculture for livelihood.
Consistent and moderate amounts of rain – as opposed to heavy or very heavy rainfall days – is thus crucial for the country’s agriculture and rural sector. Good rains can help keep prices of staples such as sugar, pulses, rice and vegetables under control, in turn restraining the sticky inflation problem.
Last year, the IMD predicted “normal” monsoon rains at 96% of the LPA, which is an average of rain recorded every year between 1971 and 2020. In reality, the season turned out to be below normal, with 94% rain recorded – which was, to be sure, within the agency’s error margin.
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 for four years in a row.
Private forecaster Skymet on April 9 issued its own analysis, predicted the monsoon to be in the “normal” range at about 102% of the long period average (LPA), with an error margin of 5%.
Monsoon rains will follow what is likely to be a hot summer, most of which will also be marked by a frenetic political campaign season as elections are held between April 19 and June 1.
Officials on Monday said though northwest India has not recorded extreme heat or heat wave, the first seven days of April were “abnormally hot” for peninsular and east India. “Telangana, Andhra Pradesh, North Interior Karnataka, parts of Tamil Nadu, Odisha, Jharkhand, Gangetic West Bengal recorded heat waves and even severe heat waves on some days. Normally, three heat wave days are recorded in April that threshold has already been crossed and we are expecting 1-2 more heat wave events during rest of the month. So people should be prepared. Information is being provided to Election Commission,” said M Mohapatra, director general, IMD.
In a separate forecast for northwest India, the IMD said the ongoing rainfall spell with thunderstorms, lightning, gusty winds and hail is likely to continue during the next 24 hours, with a fresh spell expected during April 18 to 21.
A fresh western disturbance is likely to affect Northwest India from April 18. Under its influence, widespread light to moderate rainfall/snowfall with thunderstorm, lightning and gusty winds (30-40 kmph) will occur over Jammu-Kashmir-Ladakh region, Himachal Pradesh and Uttarakhand on April 15 and during April 18 to 21.
