IMD predicts ‘normal’ monsoon in new forecast
The India Meteorological Department (IMD) said on Friday that monsoon rainfall this year is likely to be “normal” at 96% of the long period average (LPA).Updated: Jun 01, 2019 07:20 IST
The India Meteorological Department (IMD) said on Friday that monsoon rainfall this year is likely to be “normal” at 96% of the long period average (LPA), and indicated that they will be fairly evenly spread, in a forecast that should offer a degree of relief to farmers already hit by deficient pre-monsoon rain and residents of the plains enduring scorching summer heat.
IMD, in its monsoon update on Friday, stood by its earlier monsoon forecast issued on April 15. This time, IMD also provided regional forecasts for four zones--94% of LPA over north-west India, 100% of LPA over central India, 97% of LPA over the south peninsula, and 91% of LPA over northeast India, all with an error margin of +/-8%.
Private forecasters and independent experts expressed surprise that IMD was optimistic about a normal south-west monsoon despite the shadow of an El Nino, albeit weak, looming over the June-to-September monsoon months. El Nino is a weather phenomenon characterised by warm ocean temperatures in the equatorial Pacific Ocean that is associated with weak monsoon rainfall and more episodes of heat waves in the subcontinent.
In April, too, IMD had forecast monsoon rainfall to be 96% of LPA, or 50-year average, in the monsoon months, but characterised it as “near normal,” introducing a new classification. Until last year, rainfall in the range of 96% to 104% had been termed “normal” – a classification to which IMD reverted in its latest forecast.
Rains are critical for farmers in India, where around 60% of the country’s net-sown area does not have any form of irrigation. For farm output, the rains also need to be evenly distributed across regions. Robust summer rains, which account for 70% of India’s total annual rainfall, spurs rural spending on most items and as well as increases demand in other sectors of the economy. Rural sales, for instance, account for about 48% of all motorcycles and 44% of television sets sold annually if the monsoon is normal.
Monsoon was set over the south Andaman sea and some parts of south Bay of Bengal on its normal date May 18. But thereafter there has been a delay in advancement. It is likely to advance further into extreme southern parts of Arabian Sea and some more parts of Maldives and Comorin area, southwest, southeast and east central Bay of Bengal during next 72 hours according to IMD. Thereafter, monsoon is likely to strengthen and set over Kerala on June 6.
IMD, in its monsoon update, said its own and global models had indicated weak El Nino conditions will continue during the monsoon season, but with reduced intensity. Some models even suggest neutral El Nino conditions during the latter part of the monsoon season.
But the World Meteorological Organization, in an update earlier this week, said weak El Nino conditions are likely persist for three more months through the monsoon season until August. Private forecaster Skymet Weather had forecast “below normal” monsoon at 93% of LPA.
“IMD has predicted a normal monsoon at 96% of LPA with +/- 4% error margin. So the range is from 92% to 100%, which is quite wide. Skymet is expecting below normal rains. The onset is delayed, the westerly wind profile has not established till now. Rains may only pick up in July,” said Mahesh Palawat, vice president (meteorology and climate change), Skymet Weather.
“Following a brief period of weakening during early May, El Niño has intensified once again. Central Pacific Ocean is witnessing maximum warming since the last few weeks compared to the eastern parts. Thus, this pattern is emerging to be a Central Pacific El Niño and such conditions are expected to continue during June-July and with a reduced intensity in August-September,” said Akshay Deoras, a Ph.D researcher at the department of meteorology, University of Reading, UK. “As the progression of monsoon is delayed, the overall rainfall in the first three weeks of June is expected to remain below average.”
The monsoon’s progression is being delayed because the monsoon winds are weak and haven’t properly got organised in the Indian Ocean as a result of El Niño, he said. “As per the latest forecast, monsoon is expected to reach Sri Lanka around 5th June, followed by a proper arrival in Kerala and the northeastern states around 9th June. We can expect a delay of around one week in the case of east and central India,” he said.
IMD issued a two-week forecast on Friday in which it reviewed the pre-monsoon rain between March and May. According to the update, pre-monsoon is 24% deficient compared to the LPA. In south peninsula, the deficiency is as high as 48% and 29% in northwest India.
Agriculture experts have said that dry soil exacerbated by extreme heat due to lack of pre-monsoon showers will make soil preparation difficult for Kharif crops. “Delay of each day in the onset of monsoon will have impact on yields. Farmers start preparing land in May and sowing by June second week,” said GV Ramanjaneyulu, executive director, Centre for Sustainable Agriculture.