IMD says monsoon likely to be better than forecast
Probability of the Indian Ocean Dipole, which nullifies El Niño effect, has increased, says IMD chief K.J. Ramesh
New Delhi: India could receive rains that exceed earlier expectations during the June-to-September south-west monsoon season, the chief of the India Meteorological Department (IMD) said.
IMD, which will issue its second forecast for this year’s monsoon in early June, had forecast normal rain during the south-west monsoon season in its first forecast in mid-April.
“Things have improved in the latter part of the April,” said K.J. Ramesh, IMD’s director-general. The probability of the Indian Ocean Dipole, a condition that nullifies the effect of the El Niño weather phenomenon, has increased by several notches, Ramesh said.
El Niño is a weather condition that develops due to excessive warming of the Pacific Ocean, disrupting the south-west monsoon pattern and often leading to drought-like conditions in India.
The onset of monsoon kick-starts the sowing season for summer crops in the country. India receives 70% of its annual rainfall during this period, which irrigates more than half of India’s farm lands.
In its first forecast, IMD had said rainfall would be 96% of the long-period average (LPA) with a 38% probability of a near-normal monsoon. It will update these numbers in early June. The numbers were based on its forecast that El Niño would hit India towards the end of the monsoon season, around the middle or end of September.
According to IMD, there was a close to a 50% probability in March that El Niño would prevail during July-September, which was reduced to around 40% in early April. As per its latest El Niño-Southern Oscillation (ENSO ) forecast, the probability of the Indian Ocean Dipole is much higher now.
The Potsdam Institute for Climate Impact Research, a German climate institute, has also forecast on-time onset of rains. In its forecast dated 9 May, the institute said the south-west monsoon was likely to hit central India around 18 June with an error margin of about 4 days. This prediction comes with a probability of about 73%.
Ramesh said the outlook of the Australian Bureau of Meteorology (ABM) agreed with IMD’s forecast of a near normal monsoon.
“International climate models have reduced the likelihood of El Niño this year compared to last month,” ABM said in its latest ENSO outlook released on 9 May. It also said that four out of five of its climate models suggest the development of the Indian Ocean Dipole during the onset of the El Niño in the August-September period.
Data from the past 16 years show IMD’s first monsoon forecast to be off the mark vis-a-vis actual rainfall values.
Reuters on Wednesday first reported that IMD had forecast above-average rainfall in 2017.
The south-west monsoon is considered normal when the rainfall is 96-104% of its LPA and above normal if it’s greater than this.